{"title":"Color Rendering Correction Filters","description":"\u003cp\u003eShape a light source spectrum by selectively reducing wavelength regions. These filters are starting designs for evaluating color rendering with a particular source.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow to choose:\u003c\/strong\u003e Measure the combined source-and-filter spectrum. Any change in color rendering, color temperature and light output depends on the source; no universal score is implied.\u003c\/p\u003e","products":[{"product_id":"cri-8-s7","title":"CRI-8-S7 Spectral-shaping filter for color correction","description":"\u003cnav aria-label=\"Product family\"\u003e\u003cp\u003e\u003ca href=\"\/collections\/all-products\"\u003eAll optics\u003c\/a\u003e \/ \u003ca href=\"\/collections\/color-rendering-improvement-cri-filters\"\u003eColor Rendering Correction Filters\u003c\/a\u003e\u003c\/p\u003e\u003c\/nav\u003e\u003cstyle\u003e\n.ko-reviewed{color:#222;font-family:inherit;line-height:1.65;overflow-wrap:anywhere}\n.ko-reviewed *{box-sizing:border-box}.ko-reviewed h2,.ko-reviewed h3{color:#005F96;line-height:1.3}\n.ko-reviewed h2{font-size:24px;margin:0 0 1rem}.ko-reviewed h3{font-size:19px;margin:1.7rem 0 .65rem}\n.ko-reviewed p{margin:.6rem 0 1rem}.ko-reviewed ul{padding-left:1.25rem;margin:.6rem 0 1rem}\n.ko-reviewed li{padding-left:.15rem;margin:.55rem 0}.ko-reviewed .ko-note{border-left:3px solid #c9dae4;padding:.65rem 1rem;background:#f7fafc;font-size:.95em}\n.ko-reviewed a{color:#005F96;text-decoration:underline}\n\n@media(max-width:480px){.ko-reviewed h2{font-size:22px}.ko-reviewed h3{font-size:18px}.ko-reviewed .ko-note{padding:.65rem .8rem}}\n\u003c\/style\u003e\u003csection class=\"ko-reviewed\"\u003e\u003ch2 class=\"ko-catalog-description-title\"\u003eSpectral-shaping filter for color correction (CRI-8-S7)\u003c\/h2\u003e\n\u003cp\u003eCRI-8-S7 is a spectral-shaping filter for color correction. It reshapes the source spectrum by attenuating selected visible wavelengths rather than adding missing colors. Average transmission in the sample is 53.1% over 400-500 nm, 24.7% over 500-600 nm, 67.4% over 600-700 nm. The resulting light output also depends on the lamp spectrum.\u003c\/p\u003e\n\u003ch3\u003eOptical performance\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMeasured wavelength range:\u003c\/strong\u003e 380-800 nm. Performance outside this measured interval is not established by this curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e400-500 nm:\u003c\/strong\u003e Approximately 53.1% average transmission; the range is 13.4-92.8% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e500-600 nm:\u003c\/strong\u003e Approximately 24.7% average transmission; the range is 21.3-40% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e600-700 nm:\u003c\/strong\u003e Approximately 67.4% average transmission; the range is 31.3-94.4% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMeasured edge at 50% transmission:\u003c\/strong\u003e Approximately 460.6 nm. Interpolated absolute-transmission crossing, checked against the factory summary. \u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCustomization:\u003c\/strong\u003e We can customize stock and sample-book designs. Tell us the wavelength response, size and operating conditions you need.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"ko-note\"\u003eThese values come from the measured samples and help you choose a starting design. We will agree the final specification for your order. Custom versions have their own specifications and measured curves.\u003c\/p\u003e\n\u003ch3\u003eApplications to consider\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eLED and discharge-lamp development:\u003c\/strong\u003e Check whether reducing selected peaks improves the balance of your light source. Compare color rendering and luminous output before and after filtering.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eStudio and display lighting:\u003c\/strong\u003e Consider the filter when a measured color imbalance affects the desired appearance of skin tones or objects. Test with the actual source and viewing or camera conditions.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eColor-correction trials:\u003c\/strong\u003e Compare this profile with other correction filters using the same source. A color-rendering score belongs to the resulting light, so it must be measured or calculated for that combination.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eChoosing this filter\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eEvaluate the filter together with the intended light source. Color temperature, tint, color rendering and luminous output depend on that combination.\u003c\/li\u003e\n\u003cli\u003eTell us the size, shape and working angle you need, along with the temperature conditions inside the fixture.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eCustom options\u003c\/h3\u003e\n\u003cp\u003eStart with this stock or sample-book design, then tell us what you need to change. We can discuss the wavelength bands, transmission, blocking, angle, glass material, size and operating conditions with you, and agree a specification for your custom filter.\u003c\/p\u003e\u003c\/section\u003e\u003ch3\u003eTransmission spectrum\u003c\/h3\u003e\u003ciframe src=\"https:\/\/charts.kupooptics.com\/CRI-8-S7.html\" title=\"CRI-8-S7 transmission spectrum with wavelength readout\" loading=\"lazy\" width=\"100%\" height=\"880\" style=\"border:0;width:100%;height:clamp(640px,calc(43vw + 320px),880px);\" referrerpolicy=\"no-referrer-when-downgrade\"\u003e\u003c\/iframe\u003e\u003csection class=\"ko-reviewed ko-product-faq\" aria-label=\"Product questions\"\u003e\u003ch2\u003eQuestions about CRI-8-S7\u003c\/h2\u003e\n\u003ch3\u003eCan CRI-8-S7 guarantee a higher color-rendering index?\u003c\/h3\u003e\n\u003cp\u003eThe filter sample averages are 53.1% over 400-500 nm; 24.7% over 500-600 nm; 67.4% over 600-700 nm. They describe transmission, not a color-rendering score. Assess the filtered lamp spectrum or measure the complete lighting setup to find out whether the change helps your application.\u003c\/p\u003e\n\u003ch3\u003eWhat does the 50% crossing near 460.6 nm mean for CRI-8-S7?\u003c\/h3\u003e\n\u003cp\u003eIt identifies where this measured curve crosses 50% transmission. It is useful for comparing the spectral transition, but it does not give a fixed color-temperature shift or the total light output from your lamp. For CRI-8-S7, use the band averages above together with your source spectrum.\u003c\/p\u003e\u003c\/section\u003e\u003cp\u003e\u003ca href=\"\/pages\/contact\"\u003e\u003cstrong\u003eDiscuss this filter with KUPO\u003c\/strong\u003e\u003c\/a\u003e - include the product reference, source wavelength, working angle and required dimensions.\u003c\/p\u003e\u003cstyle\u003e#MainContent .ko-reviewed\u003eh2.ko-catalog-description-title{font-size:27px;font-weight:500;line-height:1.4;letter-spacing:-.01em;color:#0c324b;background:#f0f6f9;padding:20px 24px;}#MainContent .ko-reviewed\u003eh2.ko-catalog-description-title+p{border-bottom:0;}@media(max-width:650px){#MainContent .ko-reviewed\u003eh2.ko-catalog-description-title{font-size:24px;}}\u003c\/style\u003e","brand":"KUPO Optics","offers":[{"title":"Color Rendering Improvement Filter \/ Enhanced (Ra 92+)","offer_id":48516668326143,"sku":"CRI-8-S7","price":0.0,"currency_code":"TWD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0818\/8651\/1359\/files\/cri-8-s7-spectrum.jpg?v=1778712885"},{"product_id":"cri-32","title":"CRI-32 Spectral-shaping filter for color correction","description":"\u003cnav aria-label=\"Product family\"\u003e\u003cp\u003e\u003ca href=\"\/collections\/all-products\"\u003eAll optics\u003c\/a\u003e \/ \u003ca href=\"\/collections\/color-rendering-improvement-cri-filters\"\u003eColor Rendering Correction Filters\u003c\/a\u003e\u003c\/p\u003e\u003c\/nav\u003e\u003cstyle\u003e\n.ko-reviewed{color:#222;font-family:inherit;line-height:1.65;overflow-wrap:anywhere}\n.ko-reviewed *{box-sizing:border-box}.ko-reviewed h2,.ko-reviewed h3{color:#005F96;line-height:1.3}\n.ko-reviewed h2{font-size:24px;margin:0 0 1rem}.ko-reviewed h3{font-size:19px;margin:1.7rem 0 .65rem}\n.ko-reviewed p{margin:.6rem 0 1rem}.ko-reviewed ul{padding-left:1.25rem;margin:.6rem 0 1rem}\n.ko-reviewed li{padding-left:.15rem;margin:.55rem 0}.ko-reviewed .ko-note{border-left:3px solid #c9dae4;padding:.65rem 1rem;background:#f7fafc;font-size:.95em}\n.ko-reviewed a{color:#005F96;text-decoration:underline}\n\n@media(max-width:480px){.ko-reviewed h2{font-size:22px}.ko-reviewed h3{font-size:18px}.ko-reviewed .ko-note{padding:.65rem .8rem}}\n\u003c\/style\u003e\u003csection class=\"ko-reviewed\"\u003e\u003ch2 class=\"ko-catalog-description-title\"\u003eSpectral-shaping filter for color correction (CRI-32)\u003c\/h2\u003e\n\u003cp\u003eCRI-32 is a spectral-shaping filter for color correction. It reshapes the source spectrum by attenuating selected visible wavelengths rather than adding missing colors. Average transmission in the sample is 27.4% over 400-500 nm, 37.7% over 500-600 nm, 77.1% over 600-700 nm. The resulting light output also depends on the lamp spectrum.\u003c\/p\u003e\n\u003ch3\u003eOptical performance\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMeasured wavelength range:\u003c\/strong\u003e 380-800 nm. Performance outside this measured interval is not established by this curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e400-500 nm:\u003c\/strong\u003e Approximately 27.4% average transmission; the range is 9.4-43.2% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e500-600 nm:\u003c\/strong\u003e Approximately 37.7% average transmission; the range is 31-57.7% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e600-700 nm:\u003c\/strong\u003e Approximately 77.1% average transmission; the range is 57.7-85.5% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMeasured edge at 50% transmission:\u003c\/strong\u003e Approximately 590.4 nm. Interpolated absolute-transmission crossing, checked against the factory summary. \u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCustomization:\u003c\/strong\u003e We can customize stock and sample-book designs. Tell us the wavelength response, size and operating conditions you need.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"ko-note\"\u003eThese values come from the measured samples and help you choose a starting design. We will agree the final specification for your order. Custom versions have their own specifications and measured curves.\u003c\/p\u003e\n\u003ch3\u003eApplications to consider\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eLED and discharge-lamp development:\u003c\/strong\u003e Check whether reducing selected peaks improves the balance of your light source. Compare color rendering and luminous output before and after filtering.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eStudio and display lighting:\u003c\/strong\u003e Consider the filter when a measured color imbalance affects the desired appearance of skin tones or objects. Test with the actual source and viewing or camera conditions.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eColor-correction trials:\u003c\/strong\u003e Compare this profile with other correction filters using the same source. A color-rendering score belongs to the resulting light, so it must be measured or calculated for that combination.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eChoosing this filter\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eEvaluate the filter together with the intended light source. Color temperature, tint, color rendering and luminous output depend on that combination.\u003c\/li\u003e\n\u003cli\u003eTell us the size, shape and working angle you need, along with the temperature conditions inside the fixture.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eCustom options\u003c\/h3\u003e\n\u003cp\u003eStart with this stock or sample-book design, then tell us what you need to change. We can discuss the wavelength bands, transmission, blocking, angle, glass material, size and operating conditions with you, and agree a specification for your custom filter.\u003c\/p\u003e\u003c\/section\u003e\u003ch3\u003eTransmission spectrum\u003c\/h3\u003e\u003ciframe src=\"https:\/\/charts.kupooptics.com\/CRI-32.html\" title=\"CRI-32 transmission spectrum with wavelength readout\" loading=\"lazy\" width=\"100%\" height=\"880\" style=\"border:0;width:100%;height:clamp(640px,calc(43vw + 320px),880px);\" referrerpolicy=\"no-referrer-when-downgrade\"\u003e\u003c\/iframe\u003e\u003csection class=\"ko-reviewed ko-product-faq\" aria-label=\"Product questions\"\u003e\u003ch2\u003eQuestions about CRI-32\u003c\/h2\u003e\n\u003ch3\u003eWhat does the spectrum establish about CRI-32 and color rendering?\u003c\/h3\u003e\n\u003cp\u003eThe filter sample averages are 27.4% over 400-500 nm; 37.7% over 500-600 nm; 77.1% over 600-700 nm. They describe transmission, not a color-rendering score. Assess the filtered lamp spectrum or measure the complete lighting setup to find out whether the change helps your application.\u003c\/p\u003e\n\u003ch3\u003eWhat does the 50% crossing near 590.4 nm mean for CRI-32?\u003c\/h3\u003e\n\u003cp\u003eIt identifies where this measured curve crosses 50% transmission. It is useful for comparing the spectral transition, but it does not give a fixed color-temperature shift or the total light output from your lamp. For CRI-32, use the band averages above together with your source spectrum.\u003c\/p\u003e\u003c\/section\u003e\u003cp\u003e\u003ca href=\"\/pages\/contact\"\u003e\u003cstrong\u003eDiscuss this filter with KUPO\u003c\/strong\u003e\u003c\/a\u003e - include the product reference, source wavelength, working angle and required dimensions.\u003c\/p\u003e\u003cstyle\u003e#MainContent .ko-reviewed\u003eh2.ko-catalog-description-title{font-size:27px;font-weight:500;line-height:1.4;letter-spacing:-.01em;color:#0c324b;background:#f0f6f9;padding:20px 24px;}#MainContent .ko-reviewed\u003eh2.ko-catalog-description-title+p{border-bottom:0;}@media(max-width:650px){#MainContent .ko-reviewed\u003eh2.ko-catalog-description-title{font-size:24px;}}\u003c\/style\u003e","brand":"KUPO Optics","offers":[{"title":"Color Rendering Improvement Filter \/ Premium (Ra 95+)","offer_id":48516668358911,"sku":"CRI-32","price":0.0,"currency_code":"TWD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0818\/8651\/1359\/files\/cri-32-spectrum.jpg?v=1778712886"},{"product_id":"cri-31","title":"CRI-31 Spectral-shaping filter for color correction","description":"\u003cnav aria-label=\"Product family\"\u003e\u003cp\u003e\u003ca href=\"\/collections\/all-products\"\u003eAll optics\u003c\/a\u003e \/ \u003ca href=\"\/collections\/color-rendering-improvement-cri-filters\"\u003eColor Rendering Correction Filters\u003c\/a\u003e\u003c\/p\u003e\u003c\/nav\u003e\u003cstyle\u003e\n.ko-reviewed{color:#222;font-family:inherit;line-height:1.65;overflow-wrap:anywhere}\n.ko-reviewed *{box-sizing:border-box}.ko-reviewed h2,.ko-reviewed h3{color:#005F96;line-height:1.3}\n.ko-reviewed h2{font-size:24px;margin:0 0 1rem}.ko-reviewed h3{font-size:19px;margin:1.7rem 0 .65rem}\n.ko-reviewed p{margin:.6rem 0 1rem}.ko-reviewed ul{padding-left:1.25rem;margin:.6rem 0 1rem}\n.ko-reviewed li{padding-left:.15rem;margin:.55rem 0}.ko-reviewed .ko-note{border-left:3px solid #c9dae4;padding:.65rem 1rem;background:#f7fafc;font-size:.95em}\n.ko-reviewed a{color:#005F96;text-decoration:underline}\n\n@media(max-width:480px){.ko-reviewed h2{font-size:22px}.ko-reviewed h3{font-size:18px}.ko-reviewed .ko-note{padding:.65rem .8rem}}\n\u003c\/style\u003e\u003csection class=\"ko-reviewed\"\u003e\u003ch2 class=\"ko-catalog-description-title\"\u003eSpectral-shaping filter for color correction (CRI-31)\u003c\/h2\u003e\n\u003cp\u003eCRI-31 is a spectral-shaping filter for color correction. It reshapes the source spectrum by attenuating selected visible wavelengths rather than adding missing colors. Average transmission in the sample is 65.7% over 400-500 nm, 64.6% over 500-600 nm, 91.6% over 600-700 nm. The resulting light output also depends on the lamp spectrum.\u003c\/p\u003e\n\u003ch3\u003eOptical performance\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMeasured wavelength range:\u003c\/strong\u003e 380-800 nm. Performance outside this measured interval is not established by this curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e400-500 nm:\u003c\/strong\u003e Approximately 65.7% average transmission; the range is 20.5-95.8% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e500-600 nm:\u003c\/strong\u003e Approximately 64.6% average transmission; the range is 44.9-95.5% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e600-700 nm:\u003c\/strong\u003e Approximately 91.6% average transmission; the range is 66.1-96.2% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMeasured edge at 70% transmission:\u003c\/strong\u003e Approximately 533.8 nm. Interpolated absolute-transmission crossing, checked against the factory summary. \u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCustomization:\u003c\/strong\u003e We can customize stock and sample-book designs. Tell us the wavelength response, size and operating conditions you need.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"ko-note\"\u003eThese values come from the measured samples and help you choose a starting design. We will agree the final specification for your order. Custom versions have their own specifications and measured curves.\u003c\/p\u003e\n\u003ch3\u003eApplications to consider\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eLED and discharge-lamp development:\u003c\/strong\u003e Check whether reducing selected peaks improves the balance of your light source. Compare color rendering and luminous output before and after filtering.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eStudio and display lighting:\u003c\/strong\u003e Consider the filter when a measured color imbalance affects the desired appearance of skin tones or objects. Test with the actual source and viewing or camera conditions.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eColor-correction trials:\u003c\/strong\u003e Compare this profile with other correction filters using the same source. A color-rendering score belongs to the resulting light, so it must be measured or calculated for that combination.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eChoosing this filter\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eEvaluate the filter together with the intended light source. Color temperature, tint, color rendering and luminous output depend on that combination.\u003c\/li\u003e\n\u003cli\u003eTell us the size, shape and working angle you need, along with the temperature conditions inside the fixture.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eCustom options\u003c\/h3\u003e\n\u003cp\u003eStart with this stock or sample-book design, then tell us what you need to change. We can discuss the wavelength bands, transmission, blocking, angle, glass material, size and operating conditions with you, and agree a specification for your custom filter.\u003c\/p\u003e\u003c\/section\u003e\u003ch3\u003eTransmission spectrum\u003c\/h3\u003e\u003ciframe src=\"https:\/\/charts.kupooptics.com\/CRI-31.html\" title=\"CRI-31 transmission spectrum with wavelength readout\" loading=\"lazy\" width=\"100%\" height=\"880\" style=\"border:0;width:100%;height:clamp(640px,calc(43vw + 320px),880px);\" referrerpolicy=\"no-referrer-when-downgrade\"\u003e\u003c\/iframe\u003e\u003csection class=\"ko-reviewed ko-product-faq\" aria-label=\"Product questions\"\u003e\u003ch2\u003eQuestions about CRI-31\u003c\/h2\u003e\n\u003ch3\u003eHow do I judge whether CRI-31 suits my light source?\u003c\/h3\u003e\n\u003cp\u003eThe filter sample averages are 65.7% over 400-500 nm; 64.6% over 500-600 nm; 91.6% over 600-700 nm. They describe transmission, not a color-rendering score. Assess the filtered lamp spectrum or measure the complete lighting setup to find out whether the change helps your application.\u003c\/p\u003e\n\u003ch3\u003eWhat does the 70% crossing near 533.8 nm mean for CRI-31?\u003c\/h3\u003e\n\u003cp\u003eIt identifies where this measured curve crosses 70% transmission. It is useful for comparing the spectral transition, but it does not give a fixed color-temperature shift or the total light output from your lamp. For CRI-31, use the band averages above together with your source spectrum.\u003c\/p\u003e\u003c\/section\u003e\u003cp\u003e\u003ca href=\"\/pages\/contact\"\u003e\u003cstrong\u003eDiscuss this filter with KUPO\u003c\/strong\u003e\u003c\/a\u003e - include the product reference, source wavelength, working angle and required dimensions.\u003c\/p\u003e\u003cstyle\u003e#MainContent .ko-reviewed\u003eh2.ko-catalog-description-title{font-size:27px;font-weight:500;line-height:1.4;letter-spacing:-.01em;color:#0c324b;background:#f0f6f9;padding:20px 24px;}#MainContent .ko-reviewed\u003eh2.ko-catalog-description-title+p{border-bottom:0;}@media(max-width:650px){#MainContent .ko-reviewed\u003eh2.ko-catalog-description-title{font-size:24px;}}\u003c\/style\u003e","brand":"KUPO Optics","offers":[{"title":"Color Rendering Improvement Filter \/ Premium (Ra 95+)","offer_id":48516668391679,"sku":"CRI-31","price":0.0,"currency_code":"TWD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0818\/8651\/1359\/files\/cri-31-spectrum.jpg?v=1778712886"},{"product_id":"cri-30","title":"CRI-30 Spectral-shaping filter for color correction","description":"\u003cnav aria-label=\"Product family\"\u003e\u003cp\u003e\u003ca href=\"\/collections\/all-products\"\u003eAll optics\u003c\/a\u003e \/ \u003ca href=\"\/collections\/color-rendering-improvement-cri-filters\"\u003eColor Rendering Correction Filters\u003c\/a\u003e\u003c\/p\u003e\u003c\/nav\u003e\u003cstyle\u003e\n.ko-reviewed{color:#222;font-family:inherit;line-height:1.65;overflow-wrap:anywhere}\n.ko-reviewed *{box-sizing:border-box}.ko-reviewed h2,.ko-reviewed h3{color:#005F96;line-height:1.3}\n.ko-reviewed h2{font-size:24px;margin:0 0 1rem}.ko-reviewed h3{font-size:19px;margin:1.7rem 0 .65rem}\n.ko-reviewed p{margin:.6rem 0 1rem}.ko-reviewed ul{padding-left:1.25rem;margin:.6rem 0 1rem}\n.ko-reviewed li{padding-left:.15rem;margin:.55rem 0}.ko-reviewed .ko-note{border-left:3px solid #c9dae4;padding:.65rem 1rem;background:#f7fafc;font-size:.95em}\n.ko-reviewed a{color:#005F96;text-decoration:underline}\n\n@media(max-width:480px){.ko-reviewed h2{font-size:22px}.ko-reviewed h3{font-size:18px}.ko-reviewed .ko-note{padding:.65rem .8rem}}\n\u003c\/style\u003e\u003csection class=\"ko-reviewed\"\u003e\u003ch2 class=\"ko-catalog-description-title\"\u003eSpectral-shaping filter for color correction (CRI-30)\u003c\/h2\u003e\n\u003cp\u003eCRI-30 is a spectral-shaping filter for color correction. It reshapes the source spectrum by attenuating selected visible wavelengths rather than adding missing colors. Average transmission in the sample is 56.2% over 400-500 nm, 26.1% over 500-600 nm, 63.6% over 600-700 nm. The resulting light output also depends on the lamp spectrum.\u003c\/p\u003e\n\u003ch3\u003eOptical performance\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMeasured wavelength range:\u003c\/strong\u003e 380-800 nm. Performance outside this measured interval is not established by this curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e400-500 nm:\u003c\/strong\u003e Approximately 56.2% average transmission; the range is 13.3-93.2% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e500-600 nm:\u003c\/strong\u003e Approximately 26.1% average transmission; the range is 19.5-54.2% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e600-700 nm:\u003c\/strong\u003e Approximately 63.6% average transmission; the range is 29.7-96.5% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMeasured edge at 50% transmission:\u003c\/strong\u003e Approximately 422.6 nm. Interpolated absolute-transmission crossing, checked against the factory summary. \u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCustomization:\u003c\/strong\u003e We can customize stock and sample-book designs. Tell us the wavelength response, size and operating conditions you need.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"ko-note\"\u003eThese values come from the measured samples and help you choose a starting design. We will agree the final specification for your order. Custom versions have their own specifications and measured curves.\u003c\/p\u003e\n\u003ch3\u003eApplications to consider\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eLED and discharge-lamp development:\u003c\/strong\u003e Check whether reducing selected peaks improves the balance of your light source. Compare color rendering and luminous output before and after filtering.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eStudio and display lighting:\u003c\/strong\u003e Consider the filter when a measured color imbalance affects the desired appearance of skin tones or objects. Test with the actual source and viewing or camera conditions.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eColor-correction trials:\u003c\/strong\u003e Compare this profile with other correction filters using the same source. A color-rendering score belongs to the resulting light, so it must be measured or calculated for that combination.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eChoosing this filter\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eEvaluate the filter together with the intended light source. Color temperature, tint, color rendering and luminous output depend on that combination.\u003c\/li\u003e\n\u003cli\u003eTell us the size, shape and working angle you need, along with the temperature conditions inside the fixture.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eCustom options\u003c\/h3\u003e\n\u003cp\u003eStart with this stock or sample-book design, then tell us what you need to change. We can discuss the wavelength bands, transmission, blocking, angle, glass material, size and operating conditions with you, and agree a specification for your custom filter.\u003c\/p\u003e\u003c\/section\u003e\u003ch3\u003eTransmission spectrum\u003c\/h3\u003e\u003ciframe src=\"https:\/\/charts.kupooptics.com\/CRI-30.html\" title=\"CRI-30 transmission spectrum with wavelength readout\" loading=\"lazy\" width=\"100%\" height=\"880\" style=\"border:0;width:100%;height:clamp(640px,calc(43vw + 320px),880px);\" referrerpolicy=\"no-referrer-when-downgrade\"\u003e\u003c\/iframe\u003e\u003csection class=\"ko-reviewed ko-product-faq\" aria-label=\"Product questions\"\u003e\u003ch2\u003eQuestions about CRI-30\u003c\/h2\u003e\n\u003ch3\u003eCan CRI-30 guarantee a higher color-rendering index?\u003c\/h3\u003e\n\u003cp\u003eThe filter sample averages are 56.2% over 400-500 nm; 26.1% over 500-600 nm; 63.6% over 600-700 nm. They describe transmission, not a color-rendering score. Assess the filtered lamp spectrum or measure the complete lighting setup to find out whether the change helps your application.\u003c\/p\u003e\n\u003ch3\u003eWhat does the 50% crossing near 422.6 nm mean for CRI-30?\u003c\/h3\u003e\n\u003cp\u003eIt identifies where this measured curve crosses 50% transmission. It is useful for comparing the spectral transition, but it does not give a fixed color-temperature shift or the total light output from your lamp. For CRI-30, use the band averages above together with your source spectrum.\u003c\/p\u003e\u003c\/section\u003e\u003cp\u003e\u003ca href=\"\/pages\/contact\"\u003e\u003cstrong\u003eDiscuss this filter with KUPO\u003c\/strong\u003e\u003c\/a\u003e - include the product reference, source wavelength, working angle and required dimensions.\u003c\/p\u003e\u003cstyle\u003e#MainContent .ko-reviewed\u003eh2.ko-catalog-description-title{font-size:27px;font-weight:500;line-height:1.4;letter-spacing:-.01em;color:#0c324b;background:#f0f6f9;padding:20px 24px;}#MainContent .ko-reviewed\u003eh2.ko-catalog-description-title+p{border-bottom:0;}@media(max-width:650px){#MainContent .ko-reviewed\u003eh2.ko-catalog-description-title{font-size:24px;}}\u003c\/style\u003e","brand":"KUPO Optics","offers":[{"title":"Color Rendering Improvement Filter \/ Enhanced (Ra 92+)","offer_id":48516668424447,"sku":"CRI-30","price":0.0,"currency_code":"TWD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0818\/8651\/1359\/files\/cri-30-spectrum.jpg?v=1778712887"},{"product_id":"cri-29","title":"CRI-29 Spectral-shaping filter for color correction","description":"\u003cnav aria-label=\"Product family\"\u003e\u003cp\u003e\u003ca href=\"\/collections\/all-products\"\u003eAll optics\u003c\/a\u003e \/ \u003ca href=\"\/collections\/color-rendering-improvement-cri-filters\"\u003eColor Rendering Correction Filters\u003c\/a\u003e\u003c\/p\u003e\u003c\/nav\u003e\u003cstyle\u003e\n.ko-reviewed{color:#222;font-family:inherit;line-height:1.65;overflow-wrap:anywhere}\n.ko-reviewed *{box-sizing:border-box}.ko-reviewed h2,.ko-reviewed h3{color:#005F96;line-height:1.3}\n.ko-reviewed h2{font-size:24px;margin:0 0 1rem}.ko-reviewed h3{font-size:19px;margin:1.7rem 0 .65rem}\n.ko-reviewed p{margin:.6rem 0 1rem}.ko-reviewed ul{padding-left:1.25rem;margin:.6rem 0 1rem}\n.ko-reviewed li{padding-left:.15rem;margin:.55rem 0}.ko-reviewed .ko-note{border-left:3px solid #c9dae4;padding:.65rem 1rem;background:#f7fafc;font-size:.95em}\n.ko-reviewed a{color:#005F96;text-decoration:underline}\n\n@media(max-width:480px){.ko-reviewed h2{font-size:22px}.ko-reviewed h3{font-size:18px}.ko-reviewed .ko-note{padding:.65rem .8rem}}\n\u003c\/style\u003e\u003csection class=\"ko-reviewed\"\u003e\u003ch2 class=\"ko-catalog-description-title\"\u003eSpectral-shaping filter for color correction (CRI-29)\u003c\/h2\u003e\n\u003cp\u003eCRI-29 is a spectral-shaping filter for color correction. It reshapes the source spectrum by attenuating selected visible wavelengths rather than adding missing colors. Average transmission in the sample is 44.3% over 400-500 nm, 11.2% over 500-600 nm, 28.8% over 600-700 nm. The resulting light output also depends on the lamp spectrum.\u003c\/p\u003e\n\u003ch3\u003eOptical performance\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMeasured wavelength range:\u003c\/strong\u003e 380-800 nm. Performance outside this measured interval is not established by this curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e400-500 nm:\u003c\/strong\u003e Approximately 44.3% average transmission; the range is 5.6-88.1% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e500-600 nm:\u003c\/strong\u003e Approximately 11.2% average transmission; the range is 6.6-46% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e600-700 nm:\u003c\/strong\u003e Approximately 28.8% average transmission; the range is 8-87.4% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMeasured edge at 50% transmission:\u003c\/strong\u003e Approximately 474.5 nm. Interpolated absolute-transmission crossing, checked against the factory summary. \u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCustomization:\u003c\/strong\u003e We can customize stock and sample-book designs. Tell us the wavelength response, size and operating conditions you need.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"ko-note\"\u003eThese values come from the measured samples and help you choose a starting design. We will agree the final specification for your order. Custom versions have their own specifications and measured curves.\u003c\/p\u003e\n\u003ch3\u003eApplications to consider\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eLED and discharge-lamp development:\u003c\/strong\u003e Check whether reducing selected peaks improves the balance of your light source. Compare color rendering and luminous output before and after filtering.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eStudio and display lighting:\u003c\/strong\u003e Consider the filter when a measured color imbalance affects the desired appearance of skin tones or objects. Test with the actual source and viewing or camera conditions.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eColor-correction trials:\u003c\/strong\u003e Compare this profile with other correction filters using the same source. A color-rendering score belongs to the resulting light, so it must be measured or calculated for that combination.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eChoosing this filter\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eEvaluate the filter together with the intended light source. Color temperature, tint, color rendering and luminous output depend on that combination.\u003c\/li\u003e\n\u003cli\u003eTell us the size, shape and working angle you need, along with the temperature conditions inside the fixture.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eCustom options\u003c\/h3\u003e\n\u003cp\u003eStart with this stock or sample-book design, then tell us what you need to change. We can discuss the wavelength bands, transmission, blocking, angle, glass material, size and operating conditions with you, and agree a specification for your custom filter.\u003c\/p\u003e\u003c\/section\u003e\u003ch3\u003eTransmission spectrum\u003c\/h3\u003e\u003ciframe src=\"https:\/\/charts.kupooptics.com\/CRI-29.html\" title=\"CRI-29 transmission spectrum with wavelength readout\" loading=\"lazy\" width=\"100%\" height=\"880\" style=\"border:0;width:100%;height:clamp(640px,calc(43vw + 320px),880px);\" referrerpolicy=\"no-referrer-when-downgrade\"\u003e\u003c\/iframe\u003e\u003csection class=\"ko-reviewed ko-product-faq\" aria-label=\"Product questions\"\u003e\u003ch2\u003eQuestions about CRI-29\u003c\/h2\u003e\n\u003ch3\u003eWhat does the spectrum establish about CRI-29 and color rendering?\u003c\/h3\u003e\n\u003cp\u003eThe filter sample averages are 44.3% over 400-500 nm; 11.2% over 500-600 nm; 28.8% over 600-700 nm. They describe transmission, not a color-rendering score. Assess the filtered lamp spectrum or measure the complete lighting setup to find out whether the change helps your application.\u003c\/p\u003e\n\u003ch3\u003eWhat does the 50% crossing near 474.5 nm mean for CRI-29?\u003c\/h3\u003e\n\u003cp\u003eIt identifies where this measured curve crosses 50% transmission. It is useful for comparing the spectral transition, but it does not give a fixed color-temperature shift or the total light output from your lamp. For CRI-29, use the band averages above together with your source spectrum.\u003c\/p\u003e\u003c\/section\u003e\u003cp\u003e\u003ca href=\"\/pages\/contact\"\u003e\u003cstrong\u003eDiscuss this filter with KUPO\u003c\/strong\u003e\u003c\/a\u003e - include the product reference, source wavelength, working angle and required dimensions.\u003c\/p\u003e\u003cstyle\u003e#MainContent .ko-reviewed\u003eh2.ko-catalog-description-title{font-size:27px;font-weight:500;line-height:1.4;letter-spacing:-.01em;color:#0c324b;background:#f0f6f9;padding:20px 24px;}#MainContent .ko-reviewed\u003eh2.ko-catalog-description-title+p{border-bottom:0;}@media(max-width:650px){#MainContent .ko-reviewed\u003eh2.ko-catalog-description-title{font-size:24px;}}\u003c\/style\u003e","brand":"KUPO Optics","offers":[{"title":"Color Rendering Improvement Filter \/ Premium (Ra 95+)","offer_id":48516668457215,"sku":"CRI-29","price":0.0,"currency_code":"TWD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0818\/8651\/1359\/files\/cri-29-spectrum.jpg?v=1778712888"},{"product_id":"cri-28","title":"CRI-28 Spectral-shaping filter for color correction","description":"\u003cnav aria-label=\"Product family\"\u003e\u003cp\u003e\u003ca href=\"\/collections\/all-products\"\u003eAll optics\u003c\/a\u003e \/ \u003ca href=\"\/collections\/color-rendering-improvement-cri-filters\"\u003eColor Rendering Correction Filters\u003c\/a\u003e\u003c\/p\u003e\u003c\/nav\u003e\u003cstyle\u003e\n.ko-reviewed{color:#222;font-family:inherit;line-height:1.65;overflow-wrap:anywhere}\n.ko-reviewed *{box-sizing:border-box}.ko-reviewed h2,.ko-reviewed h3{color:#005F96;line-height:1.3}\n.ko-reviewed h2{font-size:24px;margin:0 0 1rem}.ko-reviewed h3{font-size:19px;margin:1.7rem 0 .65rem}\n.ko-reviewed p{margin:.6rem 0 1rem}.ko-reviewed ul{padding-left:1.25rem;margin:.6rem 0 1rem}\n.ko-reviewed li{padding-left:.15rem;margin:.55rem 0}.ko-reviewed .ko-note{border-left:3px solid #c9dae4;padding:.65rem 1rem;background:#f7fafc;font-size:.95em}\n.ko-reviewed a{color:#005F96;text-decoration:underline}\n\n@media(max-width:480px){.ko-reviewed h2{font-size:22px}.ko-reviewed h3{font-size:18px}.ko-reviewed .ko-note{padding:.65rem .8rem}}\n\u003c\/style\u003e\u003csection class=\"ko-reviewed\"\u003e\u003ch2 class=\"ko-catalog-description-title\"\u003eSpectral-shaping filter for color correction (CRI-28)\u003c\/h2\u003e\n\u003cp\u003eCRI-28 is a spectral-shaping filter for color correction. It reshapes the source spectrum by attenuating selected visible wavelengths rather than adding missing colors. Average transmission in the sample is 53.6% over 400-500 nm, 20.7% over 500-600 nm, 52.2% over 600-700 nm. The resulting light output also depends on the lamp spectrum.\u003c\/p\u003e\n\u003ch3\u003eOptical performance\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMeasured wavelength range:\u003c\/strong\u003e 380-800 nm. Performance outside this measured interval is not established by this curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e400-500 nm:\u003c\/strong\u003e Approximately 53.6% average transmission; the range is 13-91.7% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e500-600 nm:\u003c\/strong\u003e Approximately 20.7% average transmission; the range is 15.1-52.8% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e600-700 nm:\u003c\/strong\u003e Approximately 52.2% average transmission; the range is 21-92.7% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMeasured edge at 50% transmission:\u003c\/strong\u003e Approximately 424.1 nm. Interpolated absolute-transmission crossing, checked against the factory summary. \u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCustomization:\u003c\/strong\u003e We can customize stock and sample-book designs. Tell us the wavelength response, size and operating conditions you need.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"ko-note\"\u003eThese values come from the measured samples and help you choose a starting design. We will agree the final specification for your order. Custom versions have their own specifications and measured curves.\u003c\/p\u003e\n\u003ch3\u003eApplications to consider\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eLED and discharge-lamp development:\u003c\/strong\u003e Check whether reducing selected peaks improves the balance of your light source. Compare color rendering and luminous output before and after filtering.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eStudio and display lighting:\u003c\/strong\u003e Consider the filter when a measured color imbalance affects the desired appearance of skin tones or objects. Test with the actual source and viewing or camera conditions.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eColor-correction trials:\u003c\/strong\u003e Compare this profile with other correction filters using the same source. A color-rendering score belongs to the resulting light, so it must be measured or calculated for that combination.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eChoosing this filter\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eEvaluate the filter together with the intended light source. Color temperature, tint, color rendering and luminous output depend on that combination.\u003c\/li\u003e\n\u003cli\u003eTell us the size, shape and working angle you need, along with the temperature conditions inside the fixture.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eCustom options\u003c\/h3\u003e\n\u003cp\u003eStart with this stock or sample-book design, then tell us what you need to change. We can discuss the wavelength bands, transmission, blocking, angle, glass material, size and operating conditions with you, and agree a specification for your custom filter.\u003c\/p\u003e\u003c\/section\u003e\u003ch3\u003eTransmission spectrum\u003c\/h3\u003e\u003ciframe src=\"https:\/\/charts.kupooptics.com\/CRI-28.html\" title=\"CRI-28 transmission spectrum with wavelength readout\" loading=\"lazy\" width=\"100%\" height=\"880\" style=\"border:0;width:100%;height:clamp(640px,calc(43vw + 320px),880px);\" referrerpolicy=\"no-referrer-when-downgrade\"\u003e\u003c\/iframe\u003e\u003csection class=\"ko-reviewed ko-product-faq\" aria-label=\"Product questions\"\u003e\u003ch2\u003eQuestions about CRI-28\u003c\/h2\u003e\n\u003ch3\u003eHow do I judge whether CRI-28 suits my light source?\u003c\/h3\u003e\n\u003cp\u003eThe filter sample averages are 53.6% over 400-500 nm; 20.7% over 500-600 nm; 52.2% over 600-700 nm. They describe transmission, not a color-rendering score. Assess the filtered lamp spectrum or measure the complete lighting setup to find out whether the change helps your application.\u003c\/p\u003e\n\u003ch3\u003eWhat does the 50% crossing near 424.1 nm mean for CRI-28?\u003c\/h3\u003e\n\u003cp\u003eIt identifies where this measured curve crosses 50% transmission. It is useful for comparing the spectral transition, but it does not give a fixed color-temperature shift or the total light output from your lamp. For CRI-28, use the band averages above together with your source spectrum.\u003c\/p\u003e\u003c\/section\u003e\u003cp\u003e\u003ca href=\"\/pages\/contact\"\u003e\u003cstrong\u003eDiscuss this filter with KUPO\u003c\/strong\u003e\u003c\/a\u003e - include the product reference, source wavelength, working angle and required dimensions.\u003c\/p\u003e\u003cstyle\u003e#MainContent .ko-reviewed\u003eh2.ko-catalog-description-title{font-size:27px;font-weight:500;line-height:1.4;letter-spacing:-.01em;color:#0c324b;background:#f0f6f9;padding:20px 24px;}#MainContent .ko-reviewed\u003eh2.ko-catalog-description-title+p{border-bottom:0;}@media(max-width:650px){#MainContent .ko-reviewed\u003eh2.ko-catalog-description-title{font-size:24px;}}\u003c\/style\u003e","brand":"KUPO Optics","offers":[{"title":"Color Rendering Improvement Filter \/ Premium (Ra 95+)","offer_id":48516668489983,"sku":"CRI-28","price":0.0,"currency_code":"TWD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0818\/8651\/1359\/files\/cri-28-spectrum.jpg?v=1778712889"},{"product_id":"cri-27","title":"CRI-27 Spectral-shaping filter for color correction","description":"\u003cnav aria-label=\"Product family\"\u003e\u003cp\u003e\u003ca href=\"\/collections\/all-products\"\u003eAll optics\u003c\/a\u003e \/ \u003ca href=\"\/collections\/color-rendering-improvement-cri-filters\"\u003eColor Rendering Correction Filters\u003c\/a\u003e\u003c\/p\u003e\u003c\/nav\u003e\u003cstyle\u003e\n.ko-reviewed{color:#222;font-family:inherit;line-height:1.65;overflow-wrap:anywhere}\n.ko-reviewed *{box-sizing:border-box}.ko-reviewed h2,.ko-reviewed h3{color:#005F96;line-height:1.3}\n.ko-reviewed h2{font-size:24px;margin:0 0 1rem}.ko-reviewed h3{font-size:19px;margin:1.7rem 0 .65rem}\n.ko-reviewed p{margin:.6rem 0 1rem}.ko-reviewed ul{padding-left:1.25rem;margin:.6rem 0 1rem}\n.ko-reviewed li{padding-left:.15rem;margin:.55rem 0}.ko-reviewed .ko-note{border-left:3px solid #c9dae4;padding:.65rem 1rem;background:#f7fafc;font-size:.95em}\n.ko-reviewed a{color:#005F96;text-decoration:underline}\n\n@media(max-width:480px){.ko-reviewed h2{font-size:22px}.ko-reviewed h3{font-size:18px}.ko-reviewed .ko-note{padding:.65rem .8rem}}\n\u003c\/style\u003e\u003csection class=\"ko-reviewed\"\u003e\u003ch2 class=\"ko-catalog-description-title\"\u003eSpectral-shaping filter for color correction (CRI-27)\u003c\/h2\u003e\n\u003cp\u003eCRI-27 is a spectral-shaping filter for color correction. It reshapes the source spectrum by attenuating selected visible wavelengths rather than adding missing colors. Average transmission in the sample is 45.3% over 400-500 nm, 13% over 500-600 nm, 42.7% over 600-700 nm. The resulting light output also depends on the lamp spectrum.\u003c\/p\u003e\n\u003ch3\u003eOptical performance\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMeasured wavelength range:\u003c\/strong\u003e 380-800 nm. Performance outside this measured interval is not established by this curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e400-500 nm:\u003c\/strong\u003e Approximately 45.3% average transmission; the range is 6.7-90.9% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e500-600 nm:\u003c\/strong\u003e Approximately 13% average transmission; the range is 8.5-43.4% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e600-700 nm:\u003c\/strong\u003e Approximately 42.7% average transmission; the range is 10.7-93.9% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMeasured edge at 50% transmission:\u003c\/strong\u003e Approximately 417.5 nm. Interpolated absolute-transmission crossing, checked against the factory summary. \u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCustomization:\u003c\/strong\u003e We can customize stock and sample-book designs. Tell us the wavelength response, size and operating conditions you need.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"ko-note\"\u003eThese values come from the measured samples and help you choose a starting design. We will agree the final specification for your order. Custom versions have their own specifications and measured curves.\u003c\/p\u003e\n\u003ch3\u003eApplications to consider\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eLED and discharge-lamp development:\u003c\/strong\u003e Check whether reducing selected peaks improves the balance of your light source. Compare color rendering and luminous output before and after filtering.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eStudio and display lighting:\u003c\/strong\u003e Consider the filter when a measured color imbalance affects the desired appearance of skin tones or objects. Test with the actual source and viewing or camera conditions.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eColor-correction trials:\u003c\/strong\u003e Compare this profile with other correction filters using the same source. A color-rendering score belongs to the resulting light, so it must be measured or calculated for that combination.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eChoosing this filter\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eEvaluate the filter together with the intended light source. Color temperature, tint, color rendering and luminous output depend on that combination.\u003c\/li\u003e\n\u003cli\u003eTell us the size, shape and working angle you need, along with the temperature conditions inside the fixture.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eCustom options\u003c\/h3\u003e\n\u003cp\u003eStart with this stock or sample-book design, then tell us what you need to change. We can discuss the wavelength bands, transmission, blocking, angle, glass material, size and operating conditions with you, and agree a specification for your custom filter.\u003c\/p\u003e\u003c\/section\u003e\u003ch3\u003eTransmission spectrum\u003c\/h3\u003e\u003ciframe src=\"https:\/\/charts.kupooptics.com\/CRI-27.html\" title=\"CRI-27 transmission spectrum with wavelength readout\" loading=\"lazy\" width=\"100%\" height=\"880\" style=\"border:0;width:100%;height:clamp(640px,calc(43vw + 320px),880px);\" referrerpolicy=\"no-referrer-when-downgrade\"\u003e\u003c\/iframe\u003e\u003csection class=\"ko-reviewed ko-product-faq\" aria-label=\"Product questions\"\u003e\u003ch2\u003eQuestions about CRI-27\u003c\/h2\u003e\n\u003ch3\u003eCan CRI-27 guarantee a higher color-rendering index?\u003c\/h3\u003e\n\u003cp\u003eThe filter sample averages are 45.3% over 400-500 nm; 13% over 500-600 nm; 42.7% over 600-700 nm. They describe transmission, not a color-rendering score. Assess the filtered lamp spectrum or measure the complete lighting setup to find out whether the change helps your application.\u003c\/p\u003e\n\u003ch3\u003eWhat does the 50% crossing near 417.5 nm mean for CRI-27?\u003c\/h3\u003e\n\u003cp\u003eIt identifies where this measured curve crosses 50% transmission. It is useful for comparing the spectral transition, but it does not give a fixed color-temperature shift or the total light output from your lamp. For CRI-27, use the band averages above together with your source spectrum.\u003c\/p\u003e\u003c\/section\u003e\u003cp\u003e\u003ca href=\"\/pages\/contact\"\u003e\u003cstrong\u003eDiscuss this filter with KUPO\u003c\/strong\u003e\u003c\/a\u003e - include the product reference, source wavelength, working angle and required dimensions.\u003c\/p\u003e\u003cstyle\u003e#MainContent .ko-reviewed\u003eh2.ko-catalog-description-title{font-size:27px;font-weight:500;line-height:1.4;letter-spacing:-.01em;color:#0c324b;background:#f0f6f9;padding:20px 24px;}#MainContent .ko-reviewed\u003eh2.ko-catalog-description-title+p{border-bottom:0;}@media(max-width:650px){#MainContent .ko-reviewed\u003eh2.ko-catalog-description-title{font-size:24px;}}\u003c\/style\u003e","brand":"KUPO Optics","offers":[{"title":"Color Rendering Improvement Filter \/ Premium (Ra 95+)","offer_id":48516668522751,"sku":"CRI-27","price":0.0,"currency_code":"TWD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0818\/8651\/1359\/files\/cri-27-spectrum.jpg?v=1778712890"},{"product_id":"cri-26","title":"CRI-26 Spectral-shaping filter for color correction","description":"\u003cnav aria-label=\"Product family\"\u003e\u003cp\u003e\u003ca href=\"\/collections\/all-products\"\u003eAll optics\u003c\/a\u003e \/ \u003ca href=\"\/collections\/color-rendering-improvement-cri-filters\"\u003eColor Rendering Correction Filters\u003c\/a\u003e\u003c\/p\u003e\u003c\/nav\u003e\u003cstyle\u003e\n.ko-reviewed{color:#222;font-family:inherit;line-height:1.65;overflow-wrap:anywhere}\n.ko-reviewed *{box-sizing:border-box}.ko-reviewed h2,.ko-reviewed h3{color:#005F96;line-height:1.3}\n.ko-reviewed h2{font-size:24px;margin:0 0 1rem}.ko-reviewed h3{font-size:19px;margin:1.7rem 0 .65rem}\n.ko-reviewed p{margin:.6rem 0 1rem}.ko-reviewed ul{padding-left:1.25rem;margin:.6rem 0 1rem}\n.ko-reviewed li{padding-left:.15rem;margin:.55rem 0}.ko-reviewed .ko-note{border-left:3px solid #c9dae4;padding:.65rem 1rem;background:#f7fafc;font-size:.95em}\n.ko-reviewed a{color:#005F96;text-decoration:underline}\n\n@media(max-width:480px){.ko-reviewed h2{font-size:22px}.ko-reviewed h3{font-size:18px}.ko-reviewed .ko-note{padding:.65rem .8rem}}\n\u003c\/style\u003e\u003csection class=\"ko-reviewed\"\u003e\u003ch2 class=\"ko-catalog-description-title\"\u003eSpectral-shaping filter for color correction (CRI-26)\u003c\/h2\u003e\n\u003cp\u003eCRI-26 is a spectral-shaping filter for color correction. It reshapes the source spectrum by attenuating selected visible wavelengths rather than adding missing colors. Average transmission in the sample is 52.3% over 400-500 nm, 22% over 500-600 nm, 50.7% over 600-700 nm. The resulting light output also depends on the lamp spectrum.\u003c\/p\u003e\n\u003ch3\u003eOptical performance\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMeasured wavelength range:\u003c\/strong\u003e 380-800 nm. Performance outside this measured interval is not established by this curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e400-500 nm:\u003c\/strong\u003e Approximately 52.3% average transmission; the range is 9.8-94% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e500-600 nm:\u003c\/strong\u003e Approximately 22% average transmission; the range is 18-55.3% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e600-700 nm:\u003c\/strong\u003e Approximately 50.7% average transmission; the range is 19.1-94.7% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMeasured edge at 50% transmission:\u003c\/strong\u003e Approximately 421.7 nm. Interpolated absolute-transmission crossing, checked against the factory summary. \u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCustomization:\u003c\/strong\u003e We can customize stock and sample-book designs. Tell us the wavelength response, size and operating conditions you need.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"ko-note\"\u003eThese values come from the measured samples and help you choose a starting design. We will agree the final specification for your order. Custom versions have their own specifications and measured curves.\u003c\/p\u003e\n\u003ch3\u003eApplications to consider\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eLED and discharge-lamp development:\u003c\/strong\u003e Check whether reducing selected peaks improves the balance of your light source. Compare color rendering and luminous output before and after filtering.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eStudio and display lighting:\u003c\/strong\u003e Consider the filter when a measured color imbalance affects the desired appearance of skin tones or objects. Test with the actual source and viewing or camera conditions.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eColor-correction trials:\u003c\/strong\u003e Compare this profile with other correction filters using the same source. A color-rendering score belongs to the resulting light, so it must be measured or calculated for that combination.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eChoosing this filter\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eEvaluate the filter together with the intended light source. Color temperature, tint, color rendering and luminous output depend on that combination.\u003c\/li\u003e\n\u003cli\u003eTell us the size, shape and working angle you need, along with the temperature conditions inside the fixture.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eCustom options\u003c\/h3\u003e\n\u003cp\u003eStart with this stock or sample-book design, then tell us what you need to change. We can discuss the wavelength bands, transmission, blocking, angle, glass material, size and operating conditions with you, and agree a specification for your custom filter.\u003c\/p\u003e\u003c\/section\u003e\u003ch3\u003eTransmission spectrum\u003c\/h3\u003e\u003ciframe src=\"https:\/\/charts.kupooptics.com\/CRI-26.html\" title=\"CRI-26 transmission spectrum with wavelength readout\" loading=\"lazy\" width=\"100%\" height=\"880\" style=\"border:0;width:100%;height:clamp(640px,calc(43vw + 320px),880px);\" referrerpolicy=\"no-referrer-when-downgrade\"\u003e\u003c\/iframe\u003e\u003csection class=\"ko-reviewed ko-product-faq\" aria-label=\"Product questions\"\u003e\u003ch2\u003eQuestions about CRI-26\u003c\/h2\u003e\n\u003ch3\u003eWhat does the spectrum establish about CRI-26 and color rendering?\u003c\/h3\u003e\n\u003cp\u003eThe filter sample averages are 52.3% over 400-500 nm; 22% over 500-600 nm; 50.7% over 600-700 nm. They describe transmission, not a color-rendering score. Assess the filtered lamp spectrum or measure the complete lighting setup to find out whether the change helps your application.\u003c\/p\u003e\n\u003ch3\u003eWhat does the 50% crossing near 421.7 nm mean for CRI-26?\u003c\/h3\u003e\n\u003cp\u003eIt identifies where this measured curve crosses 50% transmission. It is useful for comparing the spectral transition, but it does not give a fixed color-temperature shift or the total light output from your lamp. For CRI-26, use the band averages above together with your source spectrum.\u003c\/p\u003e\u003c\/section\u003e\u003cp\u003e\u003ca href=\"\/pages\/contact\"\u003e\u003cstrong\u003eDiscuss this filter with KUPO\u003c\/strong\u003e\u003c\/a\u003e - include the product reference, source wavelength, working angle and required dimensions.\u003c\/p\u003e\u003cstyle\u003e#MainContent .ko-reviewed\u003eh2.ko-catalog-description-title{font-size:27px;font-weight:500;line-height:1.4;letter-spacing:-.01em;color:#0c324b;background:#f0f6f9;padding:20px 24px;}#MainContent .ko-reviewed\u003eh2.ko-catalog-description-title+p{border-bottom:0;}@media(max-width:650px){#MainContent .ko-reviewed\u003eh2.ko-catalog-description-title{font-size:24px;}}\u003c\/style\u003e","brand":"KUPO Optics","offers":[{"title":"Color Rendering Improvement Filter \/ Premium (Ra 95+)","offer_id":48516668555519,"sku":"CRI-26","price":0.0,"currency_code":"TWD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0818\/8651\/1359\/files\/cri-26-spectrum.jpg?v=1778712891"},{"product_id":"cri-25","title":"CRI-25 Spectral-shaping filter for color correction","description":"\u003cnav aria-label=\"Product family\"\u003e\u003cp\u003e\u003ca href=\"\/collections\/all-products\"\u003eAll optics\u003c\/a\u003e \/ \u003ca href=\"\/collections\/color-rendering-improvement-cri-filters\"\u003eColor Rendering Correction Filters\u003c\/a\u003e\u003c\/p\u003e\u003c\/nav\u003e\u003cstyle\u003e\n.ko-reviewed{color:#222;font-family:inherit;line-height:1.65;overflow-wrap:anywhere}\n.ko-reviewed *{box-sizing:border-box}.ko-reviewed h2,.ko-reviewed h3{color:#005F96;line-height:1.3}\n.ko-reviewed h2{font-size:24px;margin:0 0 1rem}.ko-reviewed h3{font-size:19px;margin:1.7rem 0 .65rem}\n.ko-reviewed p{margin:.6rem 0 1rem}.ko-reviewed ul{padding-left:1.25rem;margin:.6rem 0 1rem}\n.ko-reviewed li{padding-left:.15rem;margin:.55rem 0}.ko-reviewed .ko-note{border-left:3px solid #c9dae4;padding:.65rem 1rem;background:#f7fafc;font-size:.95em}\n.ko-reviewed a{color:#005F96;text-decoration:underline}\n\n@media(max-width:480px){.ko-reviewed h2{font-size:22px}.ko-reviewed h3{font-size:18px}.ko-reviewed .ko-note{padding:.65rem .8rem}}\n\u003c\/style\u003e\u003csection class=\"ko-reviewed\"\u003e\u003ch2 class=\"ko-catalog-description-title\"\u003eSpectral-shaping filter for color correction (CRI-25)\u003c\/h2\u003e\n\u003cp\u003eCRI-25 is a spectral-shaping filter for color correction. It reshapes the source spectrum by attenuating selected visible wavelengths rather than adding missing colors. Average transmission in the sample is 36.7% over 400-500 nm, 28.2% over 500-600 nm, 83.4% over 600-700 nm. The resulting light output also depends on the lamp spectrum.\u003c\/p\u003e\n\u003ch3\u003eOptical performance\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMeasured wavelength range:\u003c\/strong\u003e 380-800 nm. Performance outside this measured interval is not established by this curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e400-500 nm:\u003c\/strong\u003e Approximately 36.7% average transmission; the range is 5-90.8% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e500-600 nm:\u003c\/strong\u003e Approximately 28.2% average transmission; the range is 17.7-60.7% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e600-700 nm:\u003c\/strong\u003e Approximately 83.4% average transmission; the range is 38.9-94.6% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMeasured edge at 50% transmission:\u003c\/strong\u003e Approximately 416.8 nm. Interpolated absolute-transmission crossing, checked against the factory summary. \u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCustomization:\u003c\/strong\u003e We can customize stock and sample-book designs. Tell us the wavelength response, size and operating conditions you need.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"ko-note\"\u003eThese values come from the measured samples and help you choose a starting design. We will agree the final specification for your order. Custom versions have their own specifications and measured curves.\u003c\/p\u003e\n\u003ch3\u003eApplications to consider\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eLED and discharge-lamp development:\u003c\/strong\u003e Check whether reducing selected peaks improves the balance of your light source. Compare color rendering and luminous output before and after filtering.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eStudio and display lighting:\u003c\/strong\u003e Consider the filter when a measured color imbalance affects the desired appearance of skin tones or objects. Test with the actual source and viewing or camera conditions.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eColor-correction trials:\u003c\/strong\u003e Compare this profile with other correction filters using the same source. A color-rendering score belongs to the resulting light, so it must be measured or calculated for that combination.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eChoosing this filter\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eEvaluate the filter together with the intended light source. Color temperature, tint, color rendering and luminous output depend on that combination.\u003c\/li\u003e\n\u003cli\u003eTell us the size, shape and working angle you need, along with the temperature conditions inside the fixture.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eCustom options\u003c\/h3\u003e\n\u003cp\u003eStart with this stock or sample-book design, then tell us what you need to change. We can discuss the wavelength bands, transmission, blocking, angle, glass material, size and operating conditions with you, and agree a specification for your custom filter.\u003c\/p\u003e\u003c\/section\u003e\u003ch3\u003eTransmission spectrum\u003c\/h3\u003e\u003ciframe src=\"https:\/\/charts.kupooptics.com\/CRI-25.html\" title=\"CRI-25 transmission spectrum with wavelength readout\" loading=\"lazy\" width=\"100%\" height=\"880\" style=\"border:0;width:100%;height:clamp(640px,calc(43vw + 320px),880px);\" referrerpolicy=\"no-referrer-when-downgrade\"\u003e\u003c\/iframe\u003e\u003csection class=\"ko-reviewed ko-product-faq\" aria-label=\"Product questions\"\u003e\u003ch2\u003eQuestions about CRI-25\u003c\/h2\u003e\n\u003ch3\u003eHow do I judge whether CRI-25 suits my light source?\u003c\/h3\u003e\n\u003cp\u003eThe filter sample averages are 36.7% over 400-500 nm; 28.2% over 500-600 nm; 83.4% over 600-700 nm. They describe transmission, not a color-rendering score. Assess the filtered lamp spectrum or measure the complete lighting setup to find out whether the change helps your application.\u003c\/p\u003e\n\u003ch3\u003eWhat does the 50% crossing near 416.8 nm mean for CRI-25?\u003c\/h3\u003e\n\u003cp\u003eIt identifies where this measured curve crosses 50% transmission. It is useful for comparing the spectral transition, but it does not give a fixed color-temperature shift or the total light output from your lamp. For CRI-25, use the band averages above together with your source spectrum.\u003c\/p\u003e\u003c\/section\u003e\u003cp\u003e\u003ca href=\"\/pages\/contact\"\u003e\u003cstrong\u003eDiscuss this filter with KUPO\u003c\/strong\u003e\u003c\/a\u003e - include the product reference, source wavelength, working angle and required dimensions.\u003c\/p\u003e\u003cstyle\u003e#MainContent .ko-reviewed\u003eh2.ko-catalog-description-title{font-size:27px;font-weight:500;line-height:1.4;letter-spacing:-.01em;color:#0c324b;background:#f0f6f9;padding:20px 24px;}#MainContent .ko-reviewed\u003eh2.ko-catalog-description-title+p{border-bottom:0;}@media(max-width:650px){#MainContent .ko-reviewed\u003eh2.ko-catalog-description-title{font-size:24px;}}\u003c\/style\u003e","brand":"KUPO Optics","offers":[{"title":"Color Rendering Improvement Filter \/ Premium (Ra 95+)","offer_id":48516668588287,"sku":"CRI-25","price":0.0,"currency_code":"TWD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0818\/8651\/1359\/files\/cri-25-spectrum.jpg?v=1778712891"},{"product_id":"cri-24","title":"CRI-24 Spectral-shaping filter for color correction","description":"\u003cnav aria-label=\"Product family\"\u003e\u003cp\u003e\u003ca href=\"\/collections\/all-products\"\u003eAll optics\u003c\/a\u003e \/ \u003ca href=\"\/collections\/color-rendering-improvement-cri-filters\"\u003eColor Rendering Correction Filters\u003c\/a\u003e\u003c\/p\u003e\u003c\/nav\u003e\u003cstyle\u003e\n.ko-reviewed{color:#222;font-family:inherit;line-height:1.65;overflow-wrap:anywhere}\n.ko-reviewed *{box-sizing:border-box}.ko-reviewed h2,.ko-reviewed h3{color:#005F96;line-height:1.3}\n.ko-reviewed h2{font-size:24px;margin:0 0 1rem}.ko-reviewed h3{font-size:19px;margin:1.7rem 0 .65rem}\n.ko-reviewed p{margin:.6rem 0 1rem}.ko-reviewed ul{padding-left:1.25rem;margin:.6rem 0 1rem}\n.ko-reviewed li{padding-left:.15rem;margin:.55rem 0}.ko-reviewed .ko-note{border-left:3px solid #c9dae4;padding:.65rem 1rem;background:#f7fafc;font-size:.95em}\n.ko-reviewed a{color:#005F96;text-decoration:underline}\n\n@media(max-width:480px){.ko-reviewed h2{font-size:22px}.ko-reviewed h3{font-size:18px}.ko-reviewed .ko-note{padding:.65rem .8rem}}\n\u003c\/style\u003e\u003csection class=\"ko-reviewed\"\u003e\u003ch2 class=\"ko-catalog-description-title\"\u003eSpectral-shaping filter for color correction (CRI-24)\u003c\/h2\u003e\n\u003cp\u003eCRI-24 is a spectral-shaping filter for color correction. It reshapes the source spectrum by attenuating selected visible wavelengths rather than adding missing colors. Average transmission in the sample is 52.3% over 400-500 nm, 22.4% over 500-600 nm, 61.8% over 600-700 nm. The resulting light output also depends on the lamp spectrum.\u003c\/p\u003e\n\u003ch3\u003eOptical performance\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMeasured wavelength range:\u003c\/strong\u003e 380-800 nm. Performance outside this measured interval is not established by this curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e400-500 nm:\u003c\/strong\u003e Approximately 52.3% average transmission; the range is 8.8-93.2% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e500-600 nm:\u003c\/strong\u003e Approximately 22.4% average transmission; the range is 15.3-62% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e600-700 nm:\u003c\/strong\u003e Approximately 61.8% average transmission; the range is 21.3-94.4% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMeasured edge at 50% transmission:\u003c\/strong\u003e Approximately 423.3 nm. Interpolated absolute-transmission crossing, checked against the factory summary. \u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCustomization:\u003c\/strong\u003e We can customize stock and sample-book designs. Tell us the wavelength response, size and operating conditions you need.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"ko-note\"\u003eThese values come from the measured samples and help you choose a starting design. We will agree the final specification for your order. Custom versions have their own specifications and measured curves.\u003c\/p\u003e\n\u003ch3\u003eApplications to consider\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eLED and discharge-lamp development:\u003c\/strong\u003e Check whether reducing selected peaks improves the balance of your light source. Compare color rendering and luminous output before and after filtering.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eStudio and display lighting:\u003c\/strong\u003e Consider the filter when a measured color imbalance affects the desired appearance of skin tones or objects. Test with the actual source and viewing or camera conditions.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eColor-correction trials:\u003c\/strong\u003e Compare this profile with other correction filters using the same source. A color-rendering score belongs to the resulting light, so it must be measured or calculated for that combination.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eChoosing this filter\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eEvaluate the filter together with the intended light source. Color temperature, tint, color rendering and luminous output depend on that combination.\u003c\/li\u003e\n\u003cli\u003eTell us the size, shape and working angle you need, along with the temperature conditions inside the fixture.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eCustom options\u003c\/h3\u003e\n\u003cp\u003eStart with this stock or sample-book design, then tell us what you need to change. We can discuss the wavelength bands, transmission, blocking, angle, glass material, size and operating conditions with you, and agree a specification for your custom filter.\u003c\/p\u003e\u003c\/section\u003e\u003ch3\u003eTransmission spectrum\u003c\/h3\u003e\u003ciframe src=\"https:\/\/charts.kupooptics.com\/CRI-24.html\" title=\"CRI-24 transmission spectrum with wavelength readout\" loading=\"lazy\" width=\"100%\" height=\"880\" style=\"border:0;width:100%;height:clamp(640px,calc(43vw + 320px),880px);\" referrerpolicy=\"no-referrer-when-downgrade\"\u003e\u003c\/iframe\u003e\u003csection class=\"ko-reviewed ko-product-faq\" aria-label=\"Product questions\"\u003e\u003ch2\u003eQuestions about CRI-24\u003c\/h2\u003e\n\u003ch3\u003eCan CRI-24 guarantee a higher color-rendering index?\u003c\/h3\u003e\n\u003cp\u003eThe filter sample averages are 52.3% over 400-500 nm; 22.4% over 500-600 nm; 61.8% over 600-700 nm. They describe transmission, not a color-rendering score. Assess the filtered lamp spectrum or measure the complete lighting setup to find out whether the change helps your application.\u003c\/p\u003e\n\u003ch3\u003eWhat does the 50% crossing near 423.3 nm mean for CRI-24?\u003c\/h3\u003e\n\u003cp\u003eIt identifies where this measured curve crosses 50% transmission. It is useful for comparing the spectral transition, but it does not give a fixed color-temperature shift or the total light output from your lamp. For CRI-24, use the band averages above together with your source spectrum.\u003c\/p\u003e\u003c\/section\u003e\u003cp\u003e\u003ca href=\"\/pages\/contact\"\u003e\u003cstrong\u003eDiscuss this filter with KUPO\u003c\/strong\u003e\u003c\/a\u003e - include the product reference, source wavelength, working angle and required dimensions.\u003c\/p\u003e\u003cstyle\u003e#MainContent .ko-reviewed\u003eh2.ko-catalog-description-title{font-size:27px;font-weight:500;line-height:1.4;letter-spacing:-.01em;color:#0c324b;background:#f0f6f9;padding:20px 24px;}#MainContent .ko-reviewed\u003eh2.ko-catalog-description-title+p{border-bottom:0;}@media(max-width:650px){#MainContent .ko-reviewed\u003eh2.ko-catalog-description-title{font-size:24px;}}\u003c\/style\u003e","brand":"KUPO Optics","offers":[{"title":"Color Rendering Improvement Filter \/ Enhanced (Ra 92+)","offer_id":48516668653823,"sku":"CRI-24","price":0.0,"currency_code":"TWD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0818\/8651\/1359\/files\/cri-24-spectrum.jpg?v=1778712892"},{"product_id":"cri-22","title":"CRI-22 Spectral-shaping filter for color correction","description":"\u003cnav aria-label=\"Product family\"\u003e\u003cp\u003e\u003ca href=\"\/collections\/all-products\"\u003eAll optics\u003c\/a\u003e \/ \u003ca href=\"\/collections\/color-rendering-improvement-cri-filters\"\u003eColor Rendering Correction Filters\u003c\/a\u003e\u003c\/p\u003e\u003c\/nav\u003e\u003cstyle\u003e\n.ko-reviewed{color:#222;font-family:inherit;line-height:1.65;overflow-wrap:anywhere}\n.ko-reviewed *{box-sizing:border-box}.ko-reviewed h2,.ko-reviewed h3{color:#005F96;line-height:1.3}\n.ko-reviewed h2{font-size:24px;margin:0 0 1rem}.ko-reviewed h3{font-size:19px;margin:1.7rem 0 .65rem}\n.ko-reviewed p{margin:.6rem 0 1rem}.ko-reviewed ul{padding-left:1.25rem;margin:.6rem 0 1rem}\n.ko-reviewed li{padding-left:.15rem;margin:.55rem 0}.ko-reviewed .ko-note{border-left:3px solid #c9dae4;padding:.65rem 1rem;background:#f7fafc;font-size:.95em}\n.ko-reviewed a{color:#005F96;text-decoration:underline}\n\n@media(max-width:480px){.ko-reviewed h2{font-size:22px}.ko-reviewed h3{font-size:18px}.ko-reviewed .ko-note{padding:.65rem .8rem}}\n\u003c\/style\u003e\u003csection class=\"ko-reviewed\"\u003e\u003ch2 class=\"ko-catalog-description-title\"\u003eSpectral-shaping filter for color correction (CRI-22)\u003c\/h2\u003e\n\u003cp\u003eCRI-22 is a spectral-shaping filter for color correction. It reshapes the source spectrum by attenuating selected visible wavelengths rather than adding missing colors. Average transmission in the sample is 63.3% over 400-500 nm, 29.1% over 500-600 nm, 70.1% over 600-700 nm. The resulting light output also depends on the lamp spectrum.\u003c\/p\u003e\n\u003ch3\u003eOptical performance\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMeasured wavelength range:\u003c\/strong\u003e 380-800 nm. Performance outside this measured interval is not established by this curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e400-500 nm:\u003c\/strong\u003e Approximately 63.3% average transmission; the range is 17.9-91.7% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e500-600 nm:\u003c\/strong\u003e Approximately 29.1% average transmission; the range is 22.2-75.3% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e600-700 nm:\u003c\/strong\u003e Approximately 70.1% average transmission; the range is 27.5-95.5% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMeasured edge at 50% transmission:\u003c\/strong\u003e Approximately 425.5 nm. Interpolated absolute-transmission crossing, checked against the factory summary. \u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCustomization:\u003c\/strong\u003e We can customize stock and sample-book designs. Tell us the wavelength response, size and operating conditions you need.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"ko-note\"\u003eThese values come from the measured samples and help you choose a starting design. We will agree the final specification for your order. Custom versions have their own specifications and measured curves.\u003c\/p\u003e\n\u003ch3\u003eApplications to consider\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eLED and discharge-lamp development:\u003c\/strong\u003e Check whether reducing selected peaks improves the balance of your light source. Compare color rendering and luminous output before and after filtering.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eStudio and display lighting:\u003c\/strong\u003e Consider the filter when a measured color imbalance affects the desired appearance of skin tones or objects. Test with the actual source and viewing or camera conditions.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eColor-correction trials:\u003c\/strong\u003e Compare this profile with other correction filters using the same source. A color-rendering score belongs to the resulting light, so it must be measured or calculated for that combination.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eChoosing this filter\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eEvaluate the filter together with the intended light source. Color temperature, tint, color rendering and luminous output depend on that combination.\u003c\/li\u003e\n\u003cli\u003eTell us the size, shape and working angle you need, along with the temperature conditions inside the fixture.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eCustom options\u003c\/h3\u003e\n\u003cp\u003eStart with this stock or sample-book design, then tell us what you need to change. We can discuss the wavelength bands, transmission, blocking, angle, glass material, size and operating conditions with you, and agree a specification for your custom filter.\u003c\/p\u003e\u003c\/section\u003e\u003ch3\u003eTransmission spectrum\u003c\/h3\u003e\u003ciframe src=\"https:\/\/charts.kupooptics.com\/CRI-22.html\" title=\"CRI-22 transmission spectrum with wavelength readout\" loading=\"lazy\" width=\"100%\" height=\"880\" style=\"border:0;width:100%;height:clamp(640px,calc(43vw + 320px),880px);\" referrerpolicy=\"no-referrer-when-downgrade\"\u003e\u003c\/iframe\u003e\u003csection class=\"ko-reviewed ko-product-faq\" aria-label=\"Product questions\"\u003e\u003ch2\u003eQuestions about CRI-22\u003c\/h2\u003e\n\u003ch3\u003eWhat does the spectrum establish about CRI-22 and color rendering?\u003c\/h3\u003e\n\u003cp\u003eThe filter sample averages are 63.3% over 400-500 nm; 29.1% over 500-600 nm; 70.1% over 600-700 nm. They describe transmission, not a color-rendering score. Assess the filtered lamp spectrum or measure the complete lighting setup to find out whether the change helps your application.\u003c\/p\u003e\n\u003ch3\u003eWhat does the 50% crossing near 425.5 nm mean for CRI-22?\u003c\/h3\u003e\n\u003cp\u003eIt identifies where this measured curve crosses 50% transmission. It is useful for comparing the spectral transition, but it does not give a fixed color-temperature shift or the total light output from your lamp. For CRI-22, use the band averages above together with your source spectrum.\u003c\/p\u003e\u003c\/section\u003e\u003cp\u003e\u003ca href=\"\/pages\/contact\"\u003e\u003cstrong\u003eDiscuss this filter with KUPO\u003c\/strong\u003e\u003c\/a\u003e - include the product reference, source wavelength, working angle and required dimensions.\u003c\/p\u003e\u003cstyle\u003e#MainContent .ko-reviewed\u003eh2.ko-catalog-description-title{font-size:27px;font-weight:500;line-height:1.4;letter-spacing:-.01em;color:#0c324b;background:#f0f6f9;padding:20px 24px;}#MainContent .ko-reviewed\u003eh2.ko-catalog-description-title+p{border-bottom:0;}@media(max-width:650px){#MainContent .ko-reviewed\u003eh2.ko-catalog-description-title{font-size:24px;}}\u003c\/style\u003e","brand":"KUPO Optics","offers":[{"title":"Color Rendering Improvement Filter \/ Enhanced (Ra 92+)","offer_id":48516668817663,"sku":"CRI-22","price":0.0,"currency_code":"TWD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0818\/8651\/1359\/files\/cri-22-spectrum.jpg?v=1778712893"},{"product_id":"cri-21","title":"CRI-21 Spectral-shaping filter for color correction","description":"\u003cnav aria-label=\"Product family\"\u003e\u003cp\u003e\u003ca href=\"\/collections\/all-products\"\u003eAll optics\u003c\/a\u003e \/ \u003ca href=\"\/collections\/color-rendering-improvement-cri-filters\"\u003eColor Rendering Correction Filters\u003c\/a\u003e\u003c\/p\u003e\u003c\/nav\u003e\u003cstyle\u003e\n.ko-reviewed{color:#222;font-family:inherit;line-height:1.65;overflow-wrap:anywhere}\n.ko-reviewed *{box-sizing:border-box}.ko-reviewed h2,.ko-reviewed h3{color:#005F96;line-height:1.3}\n.ko-reviewed h2{font-size:24px;margin:0 0 1rem}.ko-reviewed h3{font-size:19px;margin:1.7rem 0 .65rem}\n.ko-reviewed p{margin:.6rem 0 1rem}.ko-reviewed ul{padding-left:1.25rem;margin:.6rem 0 1rem}\n.ko-reviewed li{padding-left:.15rem;margin:.55rem 0}.ko-reviewed .ko-note{border-left:3px solid #c9dae4;padding:.65rem 1rem;background:#f7fafc;font-size:.95em}\n.ko-reviewed a{color:#005F96;text-decoration:underline}\n\n@media(max-width:480px){.ko-reviewed h2{font-size:22px}.ko-reviewed h3{font-size:18px}.ko-reviewed .ko-note{padding:.65rem .8rem}}\n\u003c\/style\u003e\u003csection class=\"ko-reviewed\"\u003e\u003ch2 class=\"ko-catalog-description-title\"\u003eSpectral-shaping filter for color correction (CRI-21)\u003c\/h2\u003e\n\u003cp\u003eCRI-21 is a spectral-shaping filter for color correction. It reshapes the source spectrum by attenuating selected visible wavelengths rather than adding missing colors. Average transmission in the sample is 70% over 400-500 nm, 42.2% over 500-600 nm, 74% over 600-700 nm. The resulting light output also depends on the lamp spectrum.\u003c\/p\u003e\n\u003ch3\u003eOptical performance\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMeasured wavelength range:\u003c\/strong\u003e 380-800 nm. Performance outside this measured interval is not established by this curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e400-500 nm:\u003c\/strong\u003e Approximately 70% average transmission; the range is 25.5-92.1% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e500-600 nm:\u003c\/strong\u003e Approximately 42.2% average transmission; the range is 32.8-89.8% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e600-700 nm:\u003c\/strong\u003e Approximately 74% average transmission; the range is 37.4-95.4% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMeasured edge at 50% transmission:\u003c\/strong\u003e Approximately 519.2 nm. Interpolated absolute-transmission crossing, checked against the factory summary. \u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCustomization:\u003c\/strong\u003e We can customize stock and sample-book designs. Tell us the wavelength response, size and operating conditions you need.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"ko-note\"\u003eThese values come from the measured samples and help you choose a starting design. We will agree the final specification for your order. Custom versions have their own specifications and measured curves.\u003c\/p\u003e\n\u003ch3\u003eApplications to consider\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eLED and discharge-lamp development:\u003c\/strong\u003e Check whether reducing selected peaks improves the balance of your light source. Compare color rendering and luminous output before and after filtering.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eStudio and display lighting:\u003c\/strong\u003e Consider the filter when a measured color imbalance affects the desired appearance of skin tones or objects. Test with the actual source and viewing or camera conditions.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eColor-correction trials:\u003c\/strong\u003e Compare this profile with other correction filters using the same source. A color-rendering score belongs to the resulting light, so it must be measured or calculated for that combination.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eChoosing this filter\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eEvaluate the filter together with the intended light source. Color temperature, tint, color rendering and luminous output depend on that combination.\u003c\/li\u003e\n\u003cli\u003eTell us the size, shape and working angle you need, along with the temperature conditions inside the fixture.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eCustom options\u003c\/h3\u003e\n\u003cp\u003eStart with this stock or sample-book design, then tell us what you need to change. We can discuss the wavelength bands, transmission, blocking, angle, glass material, size and operating conditions with you, and agree a specification for your custom filter.\u003c\/p\u003e\u003c\/section\u003e\u003ch3\u003eTransmission spectrum\u003c\/h3\u003e\u003ciframe src=\"https:\/\/charts.kupooptics.com\/CRI-21.html\" title=\"CRI-21 transmission spectrum with wavelength readout\" loading=\"lazy\" width=\"100%\" height=\"880\" style=\"border:0;width:100%;height:clamp(640px,calc(43vw + 320px),880px);\" referrerpolicy=\"no-referrer-when-downgrade\"\u003e\u003c\/iframe\u003e\u003csection class=\"ko-reviewed ko-product-faq\" aria-label=\"Product questions\"\u003e\u003ch2\u003eQuestions about CRI-21\u003c\/h2\u003e\n\u003ch3\u003eHow do I judge whether CRI-21 suits my light source?\u003c\/h3\u003e\n\u003cp\u003eThe filter sample averages are 70% over 400-500 nm; 42.2% over 500-600 nm; 74% over 600-700 nm. They describe transmission, not a color-rendering score. Assess the filtered lamp spectrum or measure the complete lighting setup to find out whether the change helps your application.\u003c\/p\u003e\n\u003ch3\u003eWhat does the 50% crossing near 519.2 nm mean for CRI-21?\u003c\/h3\u003e\n\u003cp\u003eIt identifies where this measured curve crosses 50% transmission. It is useful for comparing the spectral transition, but it does not give a fixed color-temperature shift or the total light output from your lamp. For CRI-21, use the band averages above together with your source spectrum.\u003c\/p\u003e\u003c\/section\u003e\u003cp\u003e\u003ca href=\"\/pages\/contact\"\u003e\u003cstrong\u003eDiscuss this filter with KUPO\u003c\/strong\u003e\u003c\/a\u003e - include the product reference, source wavelength, working angle and required dimensions.\u003c\/p\u003e\u003cstyle\u003e#MainContent .ko-reviewed\u003eh2.ko-catalog-description-title{font-size:27px;font-weight:500;line-height:1.4;letter-spacing:-.01em;color:#0c324b;background:#f0f6f9;padding:20px 24px;}#MainContent .ko-reviewed\u003eh2.ko-catalog-description-title+p{border-bottom:0;}@media(max-width:650px){#MainContent .ko-reviewed\u003eh2.ko-catalog-description-title{font-size:24px;}}\u003c\/style\u003e","brand":"KUPO Optics","offers":[{"title":"Color Rendering Improvement Filter \/ Enhanced (Ra 92+)","offer_id":48516668850431,"sku":"CRI-21","price":0.0,"currency_code":"TWD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0818\/8651\/1359\/files\/cri-21-spectrum.jpg?v=1778712894"},{"product_id":"cri-20","title":"CRI-20 Spectral-shaping filter for color correction","description":"\u003cnav aria-label=\"Product family\"\u003e\u003cp\u003e\u003ca href=\"\/collections\/all-products\"\u003eAll optics\u003c\/a\u003e \/ \u003ca href=\"\/collections\/color-rendering-improvement-cri-filters\"\u003eColor Rendering Correction Filters\u003c\/a\u003e\u003c\/p\u003e\u003c\/nav\u003e\u003cstyle\u003e\n.ko-reviewed{color:#222;font-family:inherit;line-height:1.65;overflow-wrap:anywhere}\n.ko-reviewed *{box-sizing:border-box}.ko-reviewed h2,.ko-reviewed h3{color:#005F96;line-height:1.3}\n.ko-reviewed h2{font-size:24px;margin:0 0 1rem}.ko-reviewed h3{font-size:19px;margin:1.7rem 0 .65rem}\n.ko-reviewed p{margin:.6rem 0 1rem}.ko-reviewed ul{padding-left:1.25rem;margin:.6rem 0 1rem}\n.ko-reviewed li{padding-left:.15rem;margin:.55rem 0}.ko-reviewed .ko-note{border-left:3px solid #c9dae4;padding:.65rem 1rem;background:#f7fafc;font-size:.95em}\n.ko-reviewed a{color:#005F96;text-decoration:underline}\n\n@media(max-width:480px){.ko-reviewed h2{font-size:22px}.ko-reviewed h3{font-size:18px}.ko-reviewed .ko-note{padding:.65rem .8rem}}\n\u003c\/style\u003e\u003csection class=\"ko-reviewed\"\u003e\u003ch2 class=\"ko-catalog-description-title\"\u003eSpectral-shaping filter for color correction (CRI-20)\u003c\/h2\u003e\n\u003cp\u003eCRI-20 is a spectral-shaping filter for color correction. It reshapes the source spectrum by attenuating selected visible wavelengths rather than adding missing colors. Average transmission in the sample is 41.4% over 400-500 nm, 43.6% over 500-600 nm, 92.7% over 600-700 nm. The resulting light output also depends on the lamp spectrum.\u003c\/p\u003e\n\u003ch3\u003eOptical performance\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMeasured wavelength range:\u003c\/strong\u003e 380-800 nm. Performance outside this measured interval is not established by this curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e400-500 nm:\u003c\/strong\u003e Approximately 41.4% average transmission; the range is 12.4-89.8% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e500-600 nm:\u003c\/strong\u003e Approximately 43.6% average transmission; the range is 22.8-89.9% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e600-700 nm:\u003c\/strong\u003e Approximately 92.7% average transmission; the range is 70.5-95.6% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMeasured edge at 50% transmission:\u003c\/strong\u003e Approximately 521.5 nm. Interpolated absolute-transmission crossing, checked against the factory summary. \u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCustomization:\u003c\/strong\u003e We can customize stock and sample-book designs. Tell us the wavelength response, size and operating conditions you need.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"ko-note\"\u003eThese values come from the measured samples and help you choose a starting design. We will agree the final specification for your order. Custom versions have their own specifications and measured curves.\u003c\/p\u003e\n\u003ch3\u003eApplications to consider\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eLED and discharge-lamp development:\u003c\/strong\u003e Check whether reducing selected peaks improves the balance of your light source. Compare color rendering and luminous output before and after filtering.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eStudio and display lighting:\u003c\/strong\u003e Consider the filter when a measured color imbalance affects the desired appearance of skin tones or objects. Test with the actual source and viewing or camera conditions.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eColor-correction trials:\u003c\/strong\u003e Compare this profile with other correction filters using the same source. A color-rendering score belongs to the resulting light, so it must be measured or calculated for that combination.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eChoosing this filter\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eEvaluate the filter together with the intended light source. Color temperature, tint, color rendering and luminous output depend on that combination.\u003c\/li\u003e\n\u003cli\u003eTell us the size, shape and working angle you need, along with the temperature conditions inside the fixture.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eCustom options\u003c\/h3\u003e\n\u003cp\u003eStart with this stock or sample-book design, then tell us what you need to change. We can discuss the wavelength bands, transmission, blocking, angle, glass material, size and operating conditions with you, and agree a specification for your custom filter.\u003c\/p\u003e\u003c\/section\u003e\u003ch3\u003eTransmission spectrum\u003c\/h3\u003e\u003ciframe src=\"https:\/\/charts.kupooptics.com\/CRI-20.html\" title=\"CRI-20 transmission spectrum with wavelength readout\" loading=\"lazy\" width=\"100%\" height=\"880\" style=\"border:0;width:100%;height:clamp(640px,calc(43vw + 320px),880px);\" referrerpolicy=\"no-referrer-when-downgrade\"\u003e\u003c\/iframe\u003e\u003csection class=\"ko-reviewed ko-product-faq\" aria-label=\"Product questions\"\u003e\u003ch2\u003eQuestions about CRI-20\u003c\/h2\u003e\n\u003ch3\u003eCan CRI-20 guarantee a higher color-rendering index?\u003c\/h3\u003e\n\u003cp\u003eThe filter sample averages are 41.4% over 400-500 nm; 43.6% over 500-600 nm; 92.7% over 600-700 nm. They describe transmission, not a color-rendering score. Assess the filtered lamp spectrum or measure the complete lighting setup to find out whether the change helps your application.\u003c\/p\u003e\n\u003ch3\u003eWhat does the 50% crossing near 521.5 nm mean for CRI-20?\u003c\/h3\u003e\n\u003cp\u003eIt identifies where this measured curve crosses 50% transmission. It is useful for comparing the spectral transition, but it does not give a fixed color-temperature shift or the total light output from your lamp. For CRI-20, use the band averages above together with your source spectrum.\u003c\/p\u003e\u003c\/section\u003e\u003cp\u003e\u003ca href=\"\/pages\/contact\"\u003e\u003cstrong\u003eDiscuss this filter with KUPO\u003c\/strong\u003e\u003c\/a\u003e - include the product reference, source wavelength, working angle and required dimensions.\u003c\/p\u003e\u003cstyle\u003e#MainContent .ko-reviewed\u003eh2.ko-catalog-description-title{font-size:27px;font-weight:500;line-height:1.4;letter-spacing:-.01em;color:#0c324b;background:#f0f6f9;padding:20px 24px;}#MainContent .ko-reviewed\u003eh2.ko-catalog-description-title+p{border-bottom:0;}@media(max-width:650px){#MainContent .ko-reviewed\u003eh2.ko-catalog-description-title{font-size:24px;}}\u003c\/style\u003e","brand":"KUPO Optics","offers":[{"title":"Color Rendering Improvement Filter \/ Premium (Ra 95+)","offer_id":48516668883199,"sku":"CRI-20","price":0.0,"currency_code":"TWD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0818\/8651\/1359\/files\/cri-20-spectrum.jpg?v=1778712895"},{"product_id":"cri-19","title":"CRI-19 Spectral-shaping filter for color correction","description":"\u003cnav aria-label=\"Product family\"\u003e\u003cp\u003e\u003ca href=\"\/collections\/all-products\"\u003eAll optics\u003c\/a\u003e \/ \u003ca href=\"\/collections\/color-rendering-improvement-cri-filters\"\u003eColor Rendering Correction Filters\u003c\/a\u003e\u003c\/p\u003e\u003c\/nav\u003e\u003cstyle\u003e\n.ko-reviewed{color:#222;font-family:inherit;line-height:1.65;overflow-wrap:anywhere}\n.ko-reviewed *{box-sizing:border-box}.ko-reviewed h2,.ko-reviewed h3{color:#005F96;line-height:1.3}\n.ko-reviewed h2{font-size:24px;margin:0 0 1rem}.ko-reviewed h3{font-size:19px;margin:1.7rem 0 .65rem}\n.ko-reviewed p{margin:.6rem 0 1rem}.ko-reviewed ul{padding-left:1.25rem;margin:.6rem 0 1rem}\n.ko-reviewed li{padding-left:.15rem;margin:.55rem 0}.ko-reviewed .ko-note{border-left:3px solid #c9dae4;padding:.65rem 1rem;background:#f7fafc;font-size:.95em}\n.ko-reviewed a{color:#005F96;text-decoration:underline}\n\n@media(max-width:480px){.ko-reviewed h2{font-size:22px}.ko-reviewed h3{font-size:18px}.ko-reviewed .ko-note{padding:.65rem .8rem}}\n\u003c\/style\u003e\u003csection class=\"ko-reviewed\"\u003e\u003ch2 class=\"ko-catalog-description-title\"\u003eSpectral-shaping filter for color correction (CRI-19)\u003c\/h2\u003e\n\u003cp\u003eCRI-19 is a spectral-shaping filter for color correction. It reshapes the source spectrum by attenuating selected visible wavelengths rather than adding missing colors. Average transmission in the sample is 62.2% over 400-500 nm, 61.9% over 500-600 nm, 90.8% over 600-700 nm. The resulting light output also depends on the lamp spectrum.\u003c\/p\u003e\n\u003ch3\u003eOptical performance\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMeasured wavelength range:\u003c\/strong\u003e 380-800 nm. Performance outside this measured interval is not established by this curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e400-500 nm:\u003c\/strong\u003e Approximately 62.2% average transmission; the range is 16.6-95.7% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e500-600 nm:\u003c\/strong\u003e Approximately 61.9% average transmission; the range is 42.4-94.3% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e600-700 nm:\u003c\/strong\u003e Approximately 90.8% average transmission; the range is 65-95.8% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMeasured edge at 70% transmission:\u003c\/strong\u003e Approximately 530.5 nm. Interpolated absolute-transmission crossing, checked against the factory summary. \u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCustomization:\u003c\/strong\u003e We can customize stock and sample-book designs. Tell us the wavelength response, size and operating conditions you need.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"ko-note\"\u003eThese values come from the measured samples and help you choose a starting design. We will agree the final specification for your order. Custom versions have their own specifications and measured curves.\u003c\/p\u003e\n\u003ch3\u003eApplications to consider\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eLED and discharge-lamp development:\u003c\/strong\u003e Check whether reducing selected peaks improves the balance of your light source. Compare color rendering and luminous output before and after filtering.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eStudio and display lighting:\u003c\/strong\u003e Consider the filter when a measured color imbalance affects the desired appearance of skin tones or objects. Test with the actual source and viewing or camera conditions.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eColor-correction trials:\u003c\/strong\u003e Compare this profile with other correction filters using the same source. A color-rendering score belongs to the resulting light, so it must be measured or calculated for that combination.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eChoosing this filter\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eEvaluate the filter together with the intended light source. Color temperature, tint, color rendering and luminous output depend on that combination.\u003c\/li\u003e\n\u003cli\u003eTell us the size, shape and working angle you need, along with the temperature conditions inside the fixture.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eCustom options\u003c\/h3\u003e\n\u003cp\u003eStart with this stock or sample-book design, then tell us what you need to change. We can discuss the wavelength bands, transmission, blocking, angle, glass material, size and operating conditions with you, and agree a specification for your custom filter.\u003c\/p\u003e\u003c\/section\u003e\u003ch3\u003eTransmission spectrum\u003c\/h3\u003e\u003ciframe src=\"https:\/\/charts.kupooptics.com\/CRI-19.html\" title=\"CRI-19 transmission spectrum with wavelength readout\" loading=\"lazy\" width=\"100%\" height=\"880\" style=\"border:0;width:100%;height:clamp(640px,calc(43vw + 320px),880px);\" referrerpolicy=\"no-referrer-when-downgrade\"\u003e\u003c\/iframe\u003e\u003csection class=\"ko-reviewed ko-product-faq\" aria-label=\"Product questions\"\u003e\u003ch2\u003eQuestions about CRI-19\u003c\/h2\u003e\n\u003ch3\u003eWhat does the spectrum establish about CRI-19 and color rendering?\u003c\/h3\u003e\n\u003cp\u003eThe filter sample averages are 62.2% over 400-500 nm; 61.9% over 500-600 nm; 90.8% over 600-700 nm. They describe transmission, not a color-rendering score. Assess the filtered lamp spectrum or measure the complete lighting setup to find out whether the change helps your application.\u003c\/p\u003e\n\u003ch3\u003eWhat does the 70% crossing near 530.5 nm mean for CRI-19?\u003c\/h3\u003e\n\u003cp\u003eIt identifies where this measured curve crosses 70% transmission. It is useful for comparing the spectral transition, but it does not give a fixed color-temperature shift or the total light output from your lamp. For CRI-19, use the band averages above together with your source spectrum.\u003c\/p\u003e\u003c\/section\u003e\u003cp\u003e\u003ca href=\"\/pages\/contact\"\u003e\u003cstrong\u003eDiscuss this filter with KUPO\u003c\/strong\u003e\u003c\/a\u003e - include the product reference, source wavelength, working angle and required dimensions.\u003c\/p\u003e\u003cstyle\u003e#MainContent .ko-reviewed\u003eh2.ko-catalog-description-title{font-size:27px;font-weight:500;line-height:1.4;letter-spacing:-.01em;color:#0c324b;background:#f0f6f9;padding:20px 24px;}#MainContent .ko-reviewed\u003eh2.ko-catalog-description-title+p{border-bottom:0;}@media(max-width:650px){#MainContent .ko-reviewed\u003eh2.ko-catalog-description-title{font-size:24px;}}\u003c\/style\u003e","brand":"KUPO Optics","offers":[{"title":"Color Rendering Improvement Filter \/ Premium (Ra 95+)","offer_id":48516668915967,"sku":"CRI-19","price":0.0,"currency_code":"TWD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0818\/8651\/1359\/files\/cri-19-spectrum.jpg?v=1778712896"},{"product_id":"cri-18","title":"CRI-18 Spectral-shaping filter for color correction","description":"\u003cnav aria-label=\"Product family\"\u003e\u003cp\u003e\u003ca href=\"\/collections\/all-products\"\u003eAll optics\u003c\/a\u003e \/ \u003ca href=\"\/collections\/color-rendering-improvement-cri-filters\"\u003eColor Rendering Correction Filters\u003c\/a\u003e\u003c\/p\u003e\u003c\/nav\u003e\u003cstyle\u003e\n.ko-reviewed{color:#222;font-family:inherit;line-height:1.65;overflow-wrap:anywhere}\n.ko-reviewed *{box-sizing:border-box}.ko-reviewed h2,.ko-reviewed h3{color:#005F96;line-height:1.3}\n.ko-reviewed h2{font-size:24px;margin:0 0 1rem}.ko-reviewed h3{font-size:19px;margin:1.7rem 0 .65rem}\n.ko-reviewed p{margin:.6rem 0 1rem}.ko-reviewed ul{padding-left:1.25rem;margin:.6rem 0 1rem}\n.ko-reviewed li{padding-left:.15rem;margin:.55rem 0}.ko-reviewed .ko-note{border-left:3px solid #c9dae4;padding:.65rem 1rem;background:#f7fafc;font-size:.95em}\n.ko-reviewed a{color:#005F96;text-decoration:underline}\n\n@media(max-width:480px){.ko-reviewed h2{font-size:22px}.ko-reviewed h3{font-size:18px}.ko-reviewed .ko-note{padding:.65rem .8rem}}\n\u003c\/style\u003e\u003csection class=\"ko-reviewed\"\u003e\u003ch2 class=\"ko-catalog-description-title\"\u003eSpectral-shaping filter for color correction (CRI-18)\u003c\/h2\u003e\n\u003cp\u003eCRI-18 is a spectral-shaping filter for color correction. It reshapes the source spectrum by attenuating selected visible wavelengths rather than adding missing colors. Average transmission in the sample is 44.4% over 400-500 nm, 46.3% over 500-600 nm, 92.3% over 600-700 nm. The resulting light output also depends on the lamp spectrum.\u003c\/p\u003e\n\u003ch3\u003eOptical performance\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMeasured wavelength range:\u003c\/strong\u003e 380-800 nm. Performance outside this measured interval is not established by this curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e400-500 nm:\u003c\/strong\u003e Approximately 44.4% average transmission; the range is 12.5-92.2% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e500-600 nm:\u003c\/strong\u003e Approximately 46.3% average transmission; the range is 24.3-92.2% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e600-700 nm:\u003c\/strong\u003e Approximately 92.3% average transmission; the range is 74.4-95.2% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMeasured edge at 50% transmission:\u003c\/strong\u003e Approximately 470.4 nm. Interpolated absolute-transmission crossing, checked against the factory summary. \u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCustomization:\u003c\/strong\u003e We can customize stock and sample-book designs. Tell us the wavelength response, size and operating conditions you need.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"ko-note\"\u003eThese values come from the measured samples and help you choose a starting design. We will agree the final specification for your order. Custom versions have their own specifications and measured curves.\u003c\/p\u003e\n\u003ch3\u003eApplications to consider\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eLED and discharge-lamp development:\u003c\/strong\u003e Check whether reducing selected peaks improves the balance of your light source. Compare color rendering and luminous output before and after filtering.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eStudio and display lighting:\u003c\/strong\u003e Consider the filter when a measured color imbalance affects the desired appearance of skin tones or objects. Test with the actual source and viewing or camera conditions.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eColor-correction trials:\u003c\/strong\u003e Compare this profile with other correction filters using the same source. A color-rendering score belongs to the resulting light, so it must be measured or calculated for that combination.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eChoosing this filter\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eEvaluate the filter together with the intended light source. Color temperature, tint, color rendering and luminous output depend on that combination.\u003c\/li\u003e\n\u003cli\u003eTell us the size, shape and working angle you need, along with the temperature conditions inside the fixture.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eCustom options\u003c\/h3\u003e\n\u003cp\u003eStart with this stock or sample-book design, then tell us what you need to change. We can discuss the wavelength bands, transmission, blocking, angle, glass material, size and operating conditions with you, and agree a specification for your custom filter.\u003c\/p\u003e\u003c\/section\u003e\u003ch3\u003eTransmission spectrum\u003c\/h3\u003e\u003ciframe src=\"https:\/\/charts.kupooptics.com\/CRI-18.html\" title=\"CRI-18 transmission spectrum with wavelength readout\" loading=\"lazy\" width=\"100%\" height=\"880\" style=\"border:0;width:100%;height:clamp(640px,calc(43vw + 320px),880px);\" referrerpolicy=\"no-referrer-when-downgrade\"\u003e\u003c\/iframe\u003e\u003csection class=\"ko-reviewed ko-product-faq\" aria-label=\"Product questions\"\u003e\u003ch2\u003eQuestions about CRI-18\u003c\/h2\u003e\n\u003ch3\u003eHow do I judge whether CRI-18 suits my light source?\u003c\/h3\u003e\n\u003cp\u003eThe filter sample averages are 44.4% over 400-500 nm; 46.3% over 500-600 nm; 92.3% over 600-700 nm. They describe transmission, not a color-rendering score. Assess the filtered lamp spectrum or measure the complete lighting setup to find out whether the change helps your application.\u003c\/p\u003e\n\u003ch3\u003eWhat does the 50% crossing near 470.4 nm mean for CRI-18?\u003c\/h3\u003e\n\u003cp\u003eIt identifies where this measured curve crosses 50% transmission. It is useful for comparing the spectral transition, but it does not give a fixed color-temperature shift or the total light output from your lamp. For CRI-18, use the band averages above together with your source spectrum.\u003c\/p\u003e\u003c\/section\u003e\u003cp\u003e\u003ca href=\"\/pages\/contact\"\u003e\u003cstrong\u003eDiscuss this filter with KUPO\u003c\/strong\u003e\u003c\/a\u003e - include the product reference, source wavelength, working angle and required dimensions.\u003c\/p\u003e\u003cstyle\u003e#MainContent .ko-reviewed\u003eh2.ko-catalog-description-title{font-size:27px;font-weight:500;line-height:1.4;letter-spacing:-.01em;color:#0c324b;background:#f0f6f9;padding:20px 24px;}#MainContent .ko-reviewed\u003eh2.ko-catalog-description-title+p{border-bottom:0;}@media(max-width:650px){#MainContent .ko-reviewed\u003eh2.ko-catalog-description-title{font-size:24px;}}\u003c\/style\u003e","brand":"KUPO Optics","offers":[{"title":"Color Rendering Improvement Filter \/ Premium (Ra 95+)","offer_id":48516668948735,"sku":"CRI-18","price":0.0,"currency_code":"TWD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0818\/8651\/1359\/files\/cri-18-spectrum.jpg?v=1778712896"},{"product_id":"cri-17","title":"CRI-17 Spectral-shaping filter for color correction","description":"\u003cnav aria-label=\"Product family\"\u003e\u003cp\u003e\u003ca href=\"\/collections\/all-products\"\u003eAll optics\u003c\/a\u003e \/ \u003ca href=\"\/collections\/color-rendering-improvement-cri-filters\"\u003eColor Rendering Correction Filters\u003c\/a\u003e\u003c\/p\u003e\u003c\/nav\u003e\u003cstyle\u003e\n.ko-reviewed{color:#222;font-family:inherit;line-height:1.65;overflow-wrap:anywhere}\n.ko-reviewed *{box-sizing:border-box}.ko-reviewed h2,.ko-reviewed h3{color:#005F96;line-height:1.3}\n.ko-reviewed h2{font-size:24px;margin:0 0 1rem}.ko-reviewed h3{font-size:19px;margin:1.7rem 0 .65rem}\n.ko-reviewed p{margin:.6rem 0 1rem}.ko-reviewed ul{padding-left:1.25rem;margin:.6rem 0 1rem}\n.ko-reviewed li{padding-left:.15rem;margin:.55rem 0}.ko-reviewed .ko-note{border-left:3px solid #c9dae4;padding:.65rem 1rem;background:#f7fafc;font-size:.95em}\n.ko-reviewed a{color:#005F96;text-decoration:underline}\n\n@media(max-width:480px){.ko-reviewed h2{font-size:22px}.ko-reviewed h3{font-size:18px}.ko-reviewed .ko-note{padding:.65rem .8rem}}\n\u003c\/style\u003e\u003csection class=\"ko-reviewed\"\u003e\u003ch2 class=\"ko-catalog-description-title\"\u003eSpectral-shaping filter for color correction (CRI-17)\u003c\/h2\u003e\n\u003cp\u003eCRI-17 is a spectral-shaping filter for color correction. It reshapes the source spectrum by attenuating selected visible wavelengths rather than adding missing colors. Average transmission in the sample is 61.4% over 400-500 nm, 25.5% over 500-600 nm, 68.5% over 600-700 nm. The resulting light output also depends on the lamp spectrum.\u003c\/p\u003e\n\u003ch3\u003eOptical performance\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMeasured wavelength range:\u003c\/strong\u003e 380-800 nm. Performance outside this measured interval is not established by this curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e400-500 nm:\u003c\/strong\u003e Approximately 61.4% average transmission; the range is 15.5-90.8% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e500-600 nm:\u003c\/strong\u003e Approximately 25.5% average transmission; the range is 20.8-62.8% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e600-700 nm:\u003c\/strong\u003e Approximately 68.5% average transmission; the range is 26.3-95.5% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMeasured edge at 50% transmission:\u003c\/strong\u003e Approximately 426.1 nm. Interpolated absolute-transmission crossing, checked against the factory summary. \u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCustomization:\u003c\/strong\u003e We can customize stock and sample-book designs. Tell us the wavelength response, size and operating conditions you need.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"ko-note\"\u003eThese values come from the measured samples and help you choose a starting design. We will agree the final specification for your order. Custom versions have their own specifications and measured curves.\u003c\/p\u003e\n\u003ch3\u003eApplications to consider\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eLED and discharge-lamp development:\u003c\/strong\u003e Check whether reducing selected peaks improves the balance of your light source. Compare color rendering and luminous output before and after filtering.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eStudio and display lighting:\u003c\/strong\u003e Consider the filter when a measured color imbalance affects the desired appearance of skin tones or objects. Test with the actual source and viewing or camera conditions.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eColor-correction trials:\u003c\/strong\u003e Compare this profile with other correction filters using the same source. A color-rendering score belongs to the resulting light, so it must be measured or calculated for that combination.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eChoosing this filter\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eEvaluate the filter together with the intended light source. Color temperature, tint, color rendering and luminous output depend on that combination.\u003c\/li\u003e\n\u003cli\u003eTell us the size, shape and working angle you need, along with the temperature conditions inside the fixture.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eCustom options\u003c\/h3\u003e\n\u003cp\u003eStart with this stock or sample-book design, then tell us what you need to change. We can discuss the wavelength bands, transmission, blocking, angle, glass material, size and operating conditions with you, and agree a specification for your custom filter.\u003c\/p\u003e\u003c\/section\u003e\u003ch3\u003eTransmission spectrum\u003c\/h3\u003e\u003ciframe src=\"https:\/\/charts.kupooptics.com\/CRI-17.html\" title=\"CRI-17 transmission spectrum with wavelength readout\" loading=\"lazy\" width=\"100%\" height=\"880\" style=\"border:0;width:100%;height:clamp(640px,calc(43vw + 320px),880px);\" referrerpolicy=\"no-referrer-when-downgrade\"\u003e\u003c\/iframe\u003e\u003csection class=\"ko-reviewed ko-product-faq\" aria-label=\"Product questions\"\u003e\u003ch2\u003eQuestions about CRI-17\u003c\/h2\u003e\n\u003ch3\u003eCan CRI-17 guarantee a higher color-rendering index?\u003c\/h3\u003e\n\u003cp\u003eThe filter sample averages are 61.4% over 400-500 nm; 25.5% over 500-600 nm; 68.5% over 600-700 nm. They describe transmission, not a color-rendering score. Assess the filtered lamp spectrum or measure the complete lighting setup to find out whether the change helps your application.\u003c\/p\u003e\n\u003ch3\u003eWhat does the 50% crossing near 426.1 nm mean for CRI-17?\u003c\/h3\u003e\n\u003cp\u003eIt identifies where this measured curve crosses 50% transmission. It is useful for comparing the spectral transition, but it does not give a fixed color-temperature shift or the total light output from your lamp. For CRI-17, use the band averages above together with your source spectrum.\u003c\/p\u003e\u003c\/section\u003e\u003cp\u003e\u003ca href=\"\/pages\/contact\"\u003e\u003cstrong\u003eDiscuss this filter with KUPO\u003c\/strong\u003e\u003c\/a\u003e - include the product reference, source wavelength, working angle and required dimensions.\u003c\/p\u003e\u003cstyle\u003e#MainContent .ko-reviewed\u003eh2.ko-catalog-description-title{font-size:27px;font-weight:500;line-height:1.4;letter-spacing:-.01em;color:#0c324b;background:#f0f6f9;padding:20px 24px;}#MainContent .ko-reviewed\u003eh2.ko-catalog-description-title+p{border-bottom:0;}@media(max-width:650px){#MainContent .ko-reviewed\u003eh2.ko-catalog-description-title{font-size:24px;}}\u003c\/style\u003e","brand":"KUPO Optics","offers":[{"title":"Color Rendering Improvement Filter \/ Enhanced (Ra 92+)","offer_id":48516668981503,"sku":"CRI-17","price":0.0,"currency_code":"TWD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0818\/8651\/1359\/files\/cri-17-spectrum.jpg?v=1778712897"},{"product_id":"cri-16","title":"CRI-16 Spectral-shaping filter for color correction","description":"\u003cnav aria-label=\"Product family\"\u003e\u003cp\u003e\u003ca href=\"\/collections\/all-products\"\u003eAll optics\u003c\/a\u003e \/ \u003ca href=\"\/collections\/color-rendering-improvement-cri-filters\"\u003eColor Rendering Correction Filters\u003c\/a\u003e\u003c\/p\u003e\u003c\/nav\u003e\u003cstyle\u003e\n.ko-reviewed{color:#222;font-family:inherit;line-height:1.65;overflow-wrap:anywhere}\n.ko-reviewed *{box-sizing:border-box}.ko-reviewed h2,.ko-reviewed h3{color:#005F96;line-height:1.3}\n.ko-reviewed h2{font-size:24px;margin:0 0 1rem}.ko-reviewed h3{font-size:19px;margin:1.7rem 0 .65rem}\n.ko-reviewed p{margin:.6rem 0 1rem}.ko-reviewed ul{padding-left:1.25rem;margin:.6rem 0 1rem}\n.ko-reviewed li{padding-left:.15rem;margin:.55rem 0}.ko-reviewed .ko-note{border-left:3px solid #c9dae4;padding:.65rem 1rem;background:#f7fafc;font-size:.95em}\n.ko-reviewed a{color:#005F96;text-decoration:underline}\n\n@media(max-width:480px){.ko-reviewed h2{font-size:22px}.ko-reviewed h3{font-size:18px}.ko-reviewed .ko-note{padding:.65rem .8rem}}\n\u003c\/style\u003e\u003csection class=\"ko-reviewed\"\u003e\u003ch2 class=\"ko-catalog-description-title\"\u003eSpectral-shaping filter for color correction (CRI-16)\u003c\/h2\u003e\n\u003cp\u003eCRI-16 is a spectral-shaping filter for color correction. It reshapes the source spectrum by attenuating selected visible wavelengths rather than adding missing colors. Average transmission in the sample is 66.7% over 400-500 nm, 35.6% over 500-600 nm, 73.9% over 600-700 nm. The resulting light output also depends on the lamp spectrum.\u003c\/p\u003e\n\u003ch3\u003eOptical performance\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMeasured wavelength range:\u003c\/strong\u003e 380-800 nm. Performance outside this measured interval is not established by this curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e400-500 nm:\u003c\/strong\u003e Approximately 66.7% average transmission; the range is 20-89.9% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e500-600 nm:\u003c\/strong\u003e Approximately 35.6% average transmission; the range is 27.2-78% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e600-700 nm:\u003c\/strong\u003e Approximately 73.9% average transmission; the range is 37.7-95.5% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMeasured edge at 70% transmission:\u003c\/strong\u003e Approximately 467.9 nm. Interpolated absolute-transmission crossing, checked against the factory summary. \u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCustomization:\u003c\/strong\u003e We can customize stock and sample-book designs. Tell us the wavelength response, size and operating conditions you need.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"ko-note\"\u003eThese values come from the measured samples and help you choose a starting design. We will agree the final specification for your order. Custom versions have their own specifications and measured curves.\u003c\/p\u003e\n\u003ch3\u003eApplications to consider\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eLED and discharge-lamp development:\u003c\/strong\u003e Check whether reducing selected peaks improves the balance of your light source. Compare color rendering and luminous output before and after filtering.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eStudio and display lighting:\u003c\/strong\u003e Consider the filter when a measured color imbalance affects the desired appearance of skin tones or objects. Test with the actual source and viewing or camera conditions.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eColor-correction trials:\u003c\/strong\u003e Compare this profile with other correction filters using the same source. A color-rendering score belongs to the resulting light, so it must be measured or calculated for that combination.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eChoosing this filter\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eEvaluate the filter together with the intended light source. Color temperature, tint, color rendering and luminous output depend on that combination.\u003c\/li\u003e\n\u003cli\u003eTell us the size, shape and working angle you need, along with the temperature conditions inside the fixture.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eCustom options\u003c\/h3\u003e\n\u003cp\u003eStart with this stock or sample-book design, then tell us what you need to change. We can discuss the wavelength bands, transmission, blocking, angle, glass material, size and operating conditions with you, and agree a specification for your custom filter.\u003c\/p\u003e\u003c\/section\u003e\u003ch3\u003eTransmission spectrum\u003c\/h3\u003e\u003ciframe src=\"https:\/\/charts.kupooptics.com\/CRI-16.html\" title=\"CRI-16 transmission spectrum with wavelength readout\" loading=\"lazy\" width=\"100%\" height=\"880\" style=\"border:0;width:100%;height:clamp(640px,calc(43vw + 320px),880px);\" referrerpolicy=\"no-referrer-when-downgrade\"\u003e\u003c\/iframe\u003e\u003csection class=\"ko-reviewed ko-product-faq\" aria-label=\"Product questions\"\u003e\u003ch2\u003eQuestions about CRI-16\u003c\/h2\u003e\n\u003ch3\u003eWhat does the spectrum establish about CRI-16 and color rendering?\u003c\/h3\u003e\n\u003cp\u003eThe filter sample averages are 66.7% over 400-500 nm; 35.6% over 500-600 nm; 73.9% over 600-700 nm. They describe transmission, not a color-rendering score. Assess the filtered lamp spectrum or measure the complete lighting setup to find out whether the change helps your application.\u003c\/p\u003e\n\u003ch3\u003eWhat does the 70% crossing near 467.9 nm mean for CRI-16?\u003c\/h3\u003e\n\u003cp\u003eIt identifies where this measured curve crosses 70% transmission. It is useful for comparing the spectral transition, but it does not give a fixed color-temperature shift or the total light output from your lamp. For CRI-16, use the band averages above together with your source spectrum.\u003c\/p\u003e\u003c\/section\u003e\u003cp\u003e\u003ca href=\"\/pages\/contact\"\u003e\u003cstrong\u003eDiscuss this filter with KUPO\u003c\/strong\u003e\u003c\/a\u003e - include the product reference, source wavelength, working angle and required dimensions.\u003c\/p\u003e\u003cstyle\u003e#MainContent .ko-reviewed\u003eh2.ko-catalog-description-title{font-size:27px;font-weight:500;line-height:1.4;letter-spacing:-.01em;color:#0c324b;background:#f0f6f9;padding:20px 24px;}#MainContent .ko-reviewed\u003eh2.ko-catalog-description-title+p{border-bottom:0;}@media(max-width:650px){#MainContent .ko-reviewed\u003eh2.ko-catalog-description-title{font-size:24px;}}\u003c\/style\u003e","brand":"KUPO Optics","offers":[{"title":"Color Rendering Improvement Filter \/ Enhanced (Ra 92+)","offer_id":48516669014271,"sku":"CRI-16","price":0.0,"currency_code":"TWD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0818\/8651\/1359\/files\/cri-16-spectrum.jpg?v=1778712898"},{"product_id":"cri-14","title":"CRI-14 Spectral-shaping filter for color correction","description":"\u003cnav aria-label=\"Product family\"\u003e\u003cp\u003e\u003ca href=\"\/collections\/all-products\"\u003eAll optics\u003c\/a\u003e \/ \u003ca href=\"\/collections\/color-rendering-improvement-cri-filters\"\u003eColor Rendering Correction Filters\u003c\/a\u003e\u003c\/p\u003e\u003c\/nav\u003e\u003cstyle\u003e\n.ko-reviewed{color:#222;font-family:inherit;line-height:1.65;overflow-wrap:anywhere}\n.ko-reviewed *{box-sizing:border-box}.ko-reviewed h2,.ko-reviewed h3{color:#005F96;line-height:1.3}\n.ko-reviewed h2{font-size:24px;margin:0 0 1rem}.ko-reviewed h3{font-size:19px;margin:1.7rem 0 .65rem}\n.ko-reviewed p{margin:.6rem 0 1rem}.ko-reviewed ul{padding-left:1.25rem;margin:.6rem 0 1rem}\n.ko-reviewed li{padding-left:.15rem;margin:.55rem 0}.ko-reviewed .ko-note{border-left:3px solid #c9dae4;padding:.65rem 1rem;background:#f7fafc;font-size:.95em}\n.ko-reviewed a{color:#005F96;text-decoration:underline}\n\n@media(max-width:480px){.ko-reviewed h2{font-size:22px}.ko-reviewed h3{font-size:18px}.ko-reviewed .ko-note{padding:.65rem .8rem}}\n\u003c\/style\u003e\u003csection class=\"ko-reviewed\"\u003e\u003ch2 class=\"ko-catalog-description-title\"\u003eSpectral-shaping filter for color correction (CRI-14)\u003c\/h2\u003e\n\u003cp\u003eCRI-14 is a spectral-shaping filter for color correction. It reshapes the source spectrum by attenuating selected visible wavelengths rather than adding missing colors. Average transmission in the sample is 63.5% over 400-500 nm, 49.7% over 500-600 nm, 57.4% over 600-700 nm. The resulting light output also depends on the lamp spectrum.\u003c\/p\u003e\n\u003ch3\u003eOptical performance\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMeasured wavelength range:\u003c\/strong\u003e 380-800 nm. Performance outside this measured interval is not established by this curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e400-500 nm:\u003c\/strong\u003e Approximately 63.5% average transmission; the range is 26.6-92.3% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e500-600 nm:\u003c\/strong\u003e Approximately 49.7% average transmission; the range is 44.8-61.8% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e600-700 nm:\u003c\/strong\u003e Approximately 57.4% average transmission; the range is 44.6-92.8% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMeasured edge at 70% transmission:\u003c\/strong\u003e Approximately 439.4 nm. Interpolated absolute-transmission crossing, checked against the factory summary. \u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCustomization:\u003c\/strong\u003e We can customize stock and sample-book designs. Tell us the wavelength response, size and operating conditions you need.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"ko-note\"\u003eThese values come from the measured samples and help you choose a starting design. We will agree the final specification for your order. Custom versions have their own specifications and measured curves.\u003c\/p\u003e\n\u003ch3\u003eApplications to consider\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eLED and discharge-lamp development:\u003c\/strong\u003e Check whether reducing selected peaks improves the balance of your light source. Compare color rendering and luminous output before and after filtering.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eStudio and display lighting:\u003c\/strong\u003e Consider the filter when a measured color imbalance affects the desired appearance of skin tones or objects. Test with the actual source and viewing or camera conditions.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eColor-correction trials:\u003c\/strong\u003e Compare this profile with other correction filters using the same source. A color-rendering score belongs to the resulting light, so it must be measured or calculated for that combination.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eChoosing this filter\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eEvaluate the filter together with the intended light source. Color temperature, tint, color rendering and luminous output depend on that combination.\u003c\/li\u003e\n\u003cli\u003eTell us the size, shape and working angle you need, along with the temperature conditions inside the fixture.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eCustom options\u003c\/h3\u003e\n\u003cp\u003eStart with this stock or sample-book design, then tell us what you need to change. We can discuss the wavelength bands, transmission, blocking, angle, glass material, size and operating conditions with you, and agree a specification for your custom filter.\u003c\/p\u003e\u003c\/section\u003e\u003ch3\u003eTransmission spectrum\u003c\/h3\u003e\u003ciframe src=\"https:\/\/charts.kupooptics.com\/CRI-14.html\" title=\"CRI-14 transmission spectrum with wavelength readout\" loading=\"lazy\" width=\"100%\" height=\"880\" style=\"border:0;width:100%;height:clamp(640px,calc(43vw + 320px),880px);\" referrerpolicy=\"no-referrer-when-downgrade\"\u003e\u003c\/iframe\u003e\u003csection class=\"ko-reviewed ko-product-faq\" aria-label=\"Product questions\"\u003e\u003ch2\u003eQuestions about CRI-14\u003c\/h2\u003e\n\u003ch3\u003eHow do I judge whether CRI-14 suits my light source?\u003c\/h3\u003e\n\u003cp\u003eThe filter sample averages are 63.5% over 400-500 nm; 49.7% over 500-600 nm; 57.4% over 600-700 nm. They describe transmission, not a color-rendering score. Assess the filtered lamp spectrum or measure the complete lighting setup to find out whether the change helps your application.\u003c\/p\u003e\n\u003ch3\u003eWhat does the 70% crossing near 439.4 nm mean for CRI-14?\u003c\/h3\u003e\n\u003cp\u003eIt identifies where this measured curve crosses 70% transmission. It is useful for comparing the spectral transition, but it does not give a fixed color-temperature shift or the total light output from your lamp. For CRI-14, use the band averages above together with your source spectrum.\u003c\/p\u003e\u003c\/section\u003e\u003cp\u003e\u003ca href=\"\/pages\/contact\"\u003e\u003cstrong\u003eDiscuss this filter with KUPO\u003c\/strong\u003e\u003c\/a\u003e - include the product reference, source wavelength, working angle and required dimensions.\u003c\/p\u003e\u003cstyle\u003e#MainContent .ko-reviewed\u003eh2.ko-catalog-description-title{font-size:27px;font-weight:500;line-height:1.4;letter-spacing:-.01em;color:#0c324b;background:#f0f6f9;padding:20px 24px;}#MainContent .ko-reviewed\u003eh2.ko-catalog-description-title+p{border-bottom:0;}@media(max-width:650px){#MainContent .ko-reviewed\u003eh2.ko-catalog-description-title{font-size:24px;}}\u003c\/style\u003e","brand":"KUPO Optics","offers":[{"title":"Color Rendering Improvement Filter \/ Standard (Ra 90+)","offer_id":48516669047039,"sku":"CRI-14","price":0.0,"currency_code":"TWD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0818\/8651\/1359\/files\/cri-14-spectrum.jpg?v=1778712899"},{"product_id":"cri-11","title":"CRI-11 Spectral-shaping filter for color correction","description":"\u003cnav aria-label=\"Product family\"\u003e\u003cp\u003e\u003ca href=\"\/collections\/all-products\"\u003eAll optics\u003c\/a\u003e \/ \u003ca href=\"\/collections\/color-rendering-improvement-cri-filters\"\u003eColor Rendering Correction Filters\u003c\/a\u003e\u003c\/p\u003e\u003c\/nav\u003e\u003cstyle\u003e\n.ko-reviewed{color:#222;font-family:inherit;line-height:1.65;overflow-wrap:anywhere}\n.ko-reviewed *{box-sizing:border-box}.ko-reviewed h2,.ko-reviewed h3{color:#005F96;line-height:1.3}\n.ko-reviewed h2{font-size:24px;margin:0 0 1rem}.ko-reviewed h3{font-size:19px;margin:1.7rem 0 .65rem}\n.ko-reviewed p{margin:.6rem 0 1rem}.ko-reviewed ul{padding-left:1.25rem;margin:.6rem 0 1rem}\n.ko-reviewed li{padding-left:.15rem;margin:.55rem 0}.ko-reviewed .ko-note{border-left:3px solid #c9dae4;padding:.65rem 1rem;background:#f7fafc;font-size:.95em}\n.ko-reviewed a{color:#005F96;text-decoration:underline}\n\n@media(max-width:480px){.ko-reviewed h2{font-size:22px}.ko-reviewed h3{font-size:18px}.ko-reviewed .ko-note{padding:.65rem .8rem}}\n\u003c\/style\u003e\u003csection class=\"ko-reviewed\"\u003e\u003ch2 class=\"ko-catalog-description-title\"\u003eSpectral-shaping filter for color correction (CRI-11)\u003c\/h2\u003e\n\u003cp\u003eCRI-11 is a spectral-shaping filter for color correction. It reshapes the source spectrum by attenuating selected visible wavelengths rather than adding missing colors. Average transmission in the sample is 76.2% over 400-500 nm, 71.4% over 500-600 nm, 78% over 600-700 nm. The resulting light output also depends on the lamp spectrum.\u003c\/p\u003e\n\u003ch3\u003eOptical performance\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMeasured wavelength range:\u003c\/strong\u003e 380-800 nm. Performance outside this measured interval is not established by this curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e400-500 nm:\u003c\/strong\u003e Approximately 76.2% average transmission; the range is 40.5-94.5% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e500-600 nm:\u003c\/strong\u003e Approximately 71.4% average transmission; the range is 67.4-86.8% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e600-700 nm:\u003c\/strong\u003e Approximately 78% average transmission; the range is 64.7-95.8% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMeasured edge at 80% transmission:\u003c\/strong\u003e Approximately 477.6 nm. Interpolated absolute-transmission crossing, checked against the factory summary. \u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCustomization:\u003c\/strong\u003e We can customize stock and sample-book designs. Tell us the wavelength response, size and operating conditions you need.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"ko-note\"\u003eThese values come from the measured samples and help you choose a starting design. We will agree the final specification for your order. Custom versions have their own specifications and measured curves.\u003c\/p\u003e\n\u003ch3\u003eApplications to consider\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eLED and discharge-lamp development:\u003c\/strong\u003e Check whether reducing selected peaks improves the balance of your light source. Compare color rendering and luminous output before and after filtering.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eStudio and display lighting:\u003c\/strong\u003e Consider the filter when a measured color imbalance affects the desired appearance of skin tones or objects. Test with the actual source and viewing or camera conditions.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eColor-correction trials:\u003c\/strong\u003e Compare this profile with other correction filters using the same source. A color-rendering score belongs to the resulting light, so it must be measured or calculated for that combination.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eChoosing this filter\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eEvaluate the filter together with the intended light source. Color temperature, tint, color rendering and luminous output depend on that combination.\u003c\/li\u003e\n\u003cli\u003eTell us the size, shape and working angle you need, along with the temperature conditions inside the fixture.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eCustom options\u003c\/h3\u003e\n\u003cp\u003eStart with this stock or sample-book design, then tell us what you need to change. We can discuss the wavelength bands, transmission, blocking, angle, glass material, size and operating conditions with you, and agree a specification for your custom filter.\u003c\/p\u003e\u003c\/section\u003e\u003ch3\u003eTransmission spectrum\u003c\/h3\u003e\u003ciframe src=\"https:\/\/charts.kupooptics.com\/CRI-11.html\" title=\"CRI-11 transmission spectrum with wavelength readout\" loading=\"lazy\" width=\"100%\" height=\"880\" style=\"border:0;width:100%;height:clamp(640px,calc(43vw + 320px),880px);\" referrerpolicy=\"no-referrer-when-downgrade\"\u003e\u003c\/iframe\u003e\u003csection class=\"ko-reviewed ko-product-faq\" aria-label=\"Product questions\"\u003e\u003ch2\u003eQuestions about CRI-11\u003c\/h2\u003e\n\u003ch3\u003eCan CRI-11 guarantee a higher color-rendering index?\u003c\/h3\u003e\n\u003cp\u003eThe filter sample averages are 76.2% over 400-500 nm; 71.4% over 500-600 nm; 78% over 600-700 nm. They describe transmission, not a color-rendering score. Assess the filtered lamp spectrum or measure the complete lighting setup to find out whether the change helps your application.\u003c\/p\u003e\n\u003ch3\u003eWhat does the 80% crossing near 477.6 nm mean for CRI-11?\u003c\/h3\u003e\n\u003cp\u003eIt identifies where this measured curve crosses 80% transmission. It is useful for comparing the spectral transition, but it does not give a fixed color-temperature shift or the total light output from your lamp. For CRI-11, use the band averages above together with your source spectrum.\u003c\/p\u003e\u003c\/section\u003e\u003cp\u003e\u003ca href=\"\/pages\/contact\"\u003e\u003cstrong\u003eDiscuss this filter with KUPO\u003c\/strong\u003e\u003c\/a\u003e - include the product reference, source wavelength, working angle and required dimensions.\u003c\/p\u003e\u003cstyle\u003e#MainContent .ko-reviewed\u003eh2.ko-catalog-description-title{font-size:27px;font-weight:500;line-height:1.4;letter-spacing:-.01em;color:#0c324b;background:#f0f6f9;padding:20px 24px;}#MainContent .ko-reviewed\u003eh2.ko-catalog-description-title+p{border-bottom:0;}@media(max-width:650px){#MainContent .ko-reviewed\u003eh2.ko-catalog-description-title{font-size:24px;}}\u003c\/style\u003e","brand":"KUPO Optics","offers":[{"title":"Color Rendering Improvement Filter \/ Standard (Ra 90+)","offer_id":48516669079807,"sku":"CRI-11","price":0.0,"currency_code":"TWD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0818\/8651\/1359\/files\/cri-11-spectrum.jpg?v=1778712900"},{"product_id":"cri-10","title":"CRI-10 Spectral-shaping filter for color correction","description":"\u003cnav aria-label=\"Product family\"\u003e\u003cp\u003e\u003ca href=\"\/collections\/all-products\"\u003eAll optics\u003c\/a\u003e \/ \u003ca href=\"\/collections\/color-rendering-improvement-cri-filters\"\u003eColor Rendering Correction Filters\u003c\/a\u003e\u003c\/p\u003e\u003c\/nav\u003e\u003cstyle\u003e\n.ko-reviewed{color:#222;font-family:inherit;line-height:1.65;overflow-wrap:anywhere}\n.ko-reviewed *{box-sizing:border-box}.ko-reviewed h2,.ko-reviewed h3{color:#005F96;line-height:1.3}\n.ko-reviewed h2{font-size:24px;margin:0 0 1rem}.ko-reviewed h3{font-size:19px;margin:1.7rem 0 .65rem}\n.ko-reviewed p{margin:.6rem 0 1rem}.ko-reviewed ul{padding-left:1.25rem;margin:.6rem 0 1rem}\n.ko-reviewed li{padding-left:.15rem;margin:.55rem 0}.ko-reviewed .ko-note{border-left:3px solid #c9dae4;padding:.65rem 1rem;background:#f7fafc;font-size:.95em}\n.ko-reviewed a{color:#005F96;text-decoration:underline}\n\n@media(max-width:480px){.ko-reviewed h2{font-size:22px}.ko-reviewed h3{font-size:18px}.ko-reviewed .ko-note{padding:.65rem .8rem}}\n\u003c\/style\u003e\u003csection class=\"ko-reviewed\"\u003e\u003ch2 class=\"ko-catalog-description-title\"\u003eSpectral-shaping filter for color correction (CRI-10)\u003c\/h2\u003e\n\u003cp\u003eCRI-10 is a spectral-shaping filter for color correction. It reshapes the source spectrum by attenuating selected visible wavelengths rather than adding missing colors. Average transmission in the sample is 62.8% over 400-500 nm, 64% over 500-600 nm, 90.6% over 600-700 nm. The resulting light output also depends on the lamp spectrum.\u003c\/p\u003e\n\u003ch3\u003eOptical performance\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMeasured wavelength range:\u003c\/strong\u003e 380-800 nm. Performance outside this measured interval is not established by this curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e400-500 nm:\u003c\/strong\u003e Approximately 62.8% average transmission; the range is 15.6-94.2% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e500-600 nm:\u003c\/strong\u003e Approximately 64% average transmission; the range is 44.8-94.8% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e600-700 nm:\u003c\/strong\u003e Approximately 90.6% average transmission; the range is 70.4-95.1% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMeasured edge at 70% transmission:\u003c\/strong\u003e Approximately 531.1 nm. Interpolated absolute-transmission crossing, checked against the factory summary. \u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCustomization:\u003c\/strong\u003e We can customize stock and sample-book designs. Tell us the wavelength response, size and operating conditions you need.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"ko-note\"\u003eThese values come from the measured samples and help you choose a starting design. We will agree the final specification for your order. Custom versions have their own specifications and measured curves.\u003c\/p\u003e\n\u003ch3\u003eApplications to consider\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eLED and discharge-lamp development:\u003c\/strong\u003e Check whether reducing selected peaks improves the balance of your light source. Compare color rendering and luminous output before and after filtering.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eStudio and display lighting:\u003c\/strong\u003e Consider the filter when a measured color imbalance affects the desired appearance of skin tones or objects. Test with the actual source and viewing or camera conditions.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eColor-correction trials:\u003c\/strong\u003e Compare this profile with other correction filters using the same source. A color-rendering score belongs to the resulting light, so it must be measured or calculated for that combination.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eChoosing this filter\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eEvaluate the filter together with the intended light source. Color temperature, tint, color rendering and luminous output depend on that combination.\u003c\/li\u003e\n\u003cli\u003eTell us the size, shape and working angle you need, along with the temperature conditions inside the fixture.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eCustom options\u003c\/h3\u003e\n\u003cp\u003eStart with this stock or sample-book design, then tell us what you need to change. We can discuss the wavelength bands, transmission, blocking, angle, glass material, size and operating conditions with you, and agree a specification for your custom filter.\u003c\/p\u003e\u003c\/section\u003e\u003ch3\u003eTransmission spectrum\u003c\/h3\u003e\u003ciframe src=\"https:\/\/charts.kupooptics.com\/CRI-10.html\" title=\"CRI-10 transmission spectrum with wavelength readout\" loading=\"lazy\" width=\"100%\" height=\"880\" style=\"border:0;width:100%;height:clamp(640px,calc(43vw + 320px),880px);\" referrerpolicy=\"no-referrer-when-downgrade\"\u003e\u003c\/iframe\u003e\u003csection class=\"ko-reviewed ko-product-faq\" aria-label=\"Product questions\"\u003e\u003ch2\u003eQuestions about CRI-10\u003c\/h2\u003e\n\u003ch3\u003eWhat does the spectrum establish about CRI-10 and color rendering?\u003c\/h3\u003e\n\u003cp\u003eThe filter sample averages are 62.8% over 400-500 nm; 64% over 500-600 nm; 90.6% over 600-700 nm. They describe transmission, not a color-rendering score. Assess the filtered lamp spectrum or measure the complete lighting setup to find out whether the change helps your application.\u003c\/p\u003e\n\u003ch3\u003eWhat does the 70% crossing near 531.1 nm mean for CRI-10?\u003c\/h3\u003e\n\u003cp\u003eIt identifies where this measured curve crosses 70% transmission. It is useful for comparing the spectral transition, but it does not give a fixed color-temperature shift or the total light output from your lamp. For CRI-10, use the band averages above together with your source spectrum.\u003c\/p\u003e\u003c\/section\u003e\u003cp\u003e\u003ca href=\"\/pages\/contact\"\u003e\u003cstrong\u003eDiscuss this filter with KUPO\u003c\/strong\u003e\u003c\/a\u003e - include the product reference, source wavelength, working angle and required dimensions.\u003c\/p\u003e\u003cstyle\u003e#MainContent .ko-reviewed\u003eh2.ko-catalog-description-title{font-size:27px;font-weight:500;line-height:1.4;letter-spacing:-.01em;color:#0c324b;background:#f0f6f9;padding:20px 24px;}#MainContent .ko-reviewed\u003eh2.ko-catalog-description-title+p{border-bottom:0;}@media(max-width:650px){#MainContent .ko-reviewed\u003eh2.ko-catalog-description-title{font-size:24px;}}\u003c\/style\u003e","brand":"KUPO Optics","offers":[{"title":"Color Rendering Improvement Filter \/ Premium (Ra 95+)","offer_id":48516669112575,"sku":"CRI-10","price":0.0,"currency_code":"TWD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0818\/8651\/1359\/files\/cri-10-spectrum.jpg?v=1778712901"},{"product_id":"cri-9","title":"CRI-9 Spectral-shaping filter for color correction","description":"\u003cnav aria-label=\"Product family\"\u003e\u003cp\u003e\u003ca href=\"\/collections\/all-products\"\u003eAll optics\u003c\/a\u003e \/ \u003ca href=\"\/collections\/color-rendering-improvement-cri-filters\"\u003eColor Rendering Correction Filters\u003c\/a\u003e\u003c\/p\u003e\u003c\/nav\u003e\u003cstyle\u003e\n.ko-reviewed{color:#222;font-family:inherit;line-height:1.65;overflow-wrap:anywhere}\n.ko-reviewed *{box-sizing:border-box}.ko-reviewed h2,.ko-reviewed h3{color:#005F96;line-height:1.3}\n.ko-reviewed h2{font-size:24px;margin:0 0 1rem}.ko-reviewed h3{font-size:19px;margin:1.7rem 0 .65rem}\n.ko-reviewed p{margin:.6rem 0 1rem}.ko-reviewed ul{padding-left:1.25rem;margin:.6rem 0 1rem}\n.ko-reviewed li{padding-left:.15rem;margin:.55rem 0}.ko-reviewed .ko-note{border-left:3px solid #c9dae4;padding:.65rem 1rem;background:#f7fafc;font-size:.95em}\n.ko-reviewed a{color:#005F96;text-decoration:underline}\n\n@media(max-width:480px){.ko-reviewed h2{font-size:22px}.ko-reviewed h3{font-size:18px}.ko-reviewed .ko-note{padding:.65rem .8rem}}\n\u003c\/style\u003e\u003csection class=\"ko-reviewed\"\u003e\u003ch2 class=\"ko-catalog-description-title\"\u003eSpectral-shaping filter for color correction (CRI-9)\u003c\/h2\u003e\n\u003cp\u003eCRI-9 is a spectral-shaping filter for color correction. It reshapes the source spectrum by attenuating selected visible wavelengths rather than adding missing colors. Average transmission in the sample is 44.6% over 400-500 nm, 17.4% over 500-600 nm, 50.6% over 600-700 nm. The resulting light output also depends on the lamp spectrum.\u003c\/p\u003e\n\u003ch3\u003eOptical performance\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMeasured wavelength range:\u003c\/strong\u003e 380-800 nm. Performance outside this measured interval is not established by this curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e400-500 nm:\u003c\/strong\u003e Approximately 44.6% average transmission; the range is 6.7-93.3% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e500-600 nm:\u003c\/strong\u003e Approximately 17.4% average transmission; the range is 13.9-41.4% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e600-700 nm:\u003c\/strong\u003e Approximately 50.6% average transmission; the range is 20.5-93.8% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMeasured edge at 50% transmission:\u003c\/strong\u003e Approximately 419.1 nm. Interpolated absolute-transmission crossing, checked against the factory summary. \u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCustomization:\u003c\/strong\u003e We can customize stock and sample-book designs. Tell us the wavelength response, size and operating conditions you need.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"ko-note\"\u003eThese values come from the measured samples and help you choose a starting design. We will agree the final specification for your order. Custom versions have their own specifications and measured curves.\u003c\/p\u003e\n\u003ch3\u003eApplications to consider\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eLED and discharge-lamp development:\u003c\/strong\u003e Check whether reducing selected peaks improves the balance of your light source. Compare color rendering and luminous output before and after filtering.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eStudio and display lighting:\u003c\/strong\u003e Consider the filter when a measured color imbalance affects the desired appearance of skin tones or objects. Test with the actual source and viewing or camera conditions.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eColor-correction trials:\u003c\/strong\u003e Compare this profile with other correction filters using the same source. A color-rendering score belongs to the resulting light, so it must be measured or calculated for that combination.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eChoosing this filter\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eEvaluate the filter together with the intended light source. Color temperature, tint, color rendering and luminous output depend on that combination.\u003c\/li\u003e\n\u003cli\u003eTell us the size, shape and working angle you need, along with the temperature conditions inside the fixture.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eCustom options\u003c\/h3\u003e\n\u003cp\u003eStart with this stock or sample-book design, then tell us what you need to change. We can discuss the wavelength bands, transmission, blocking, angle, glass material, size and operating conditions with you, and agree a specification for your custom filter.\u003c\/p\u003e\u003c\/section\u003e\u003ch3\u003eTransmission spectrum\u003c\/h3\u003e\u003ciframe src=\"https:\/\/charts.kupooptics.com\/CRI-9.html\" title=\"CRI-9 transmission spectrum with wavelength readout\" loading=\"lazy\" width=\"100%\" height=\"880\" style=\"border:0;width:100%;height:clamp(640px,calc(43vw + 320px),880px);\" referrerpolicy=\"no-referrer-when-downgrade\"\u003e\u003c\/iframe\u003e\u003csection class=\"ko-reviewed ko-product-faq\" aria-label=\"Product questions\"\u003e\u003ch2\u003eQuestions about CRI-9\u003c\/h2\u003e\n\u003ch3\u003eHow do I judge whether CRI-9 suits my light source?\u003c\/h3\u003e\n\u003cp\u003eThe filter sample averages are 44.6% over 400-500 nm; 17.4% over 500-600 nm; 50.6% over 600-700 nm. They describe transmission, not a color-rendering score. Assess the filtered lamp spectrum or measure the complete lighting setup to find out whether the change helps your application.\u003c\/p\u003e\n\u003ch3\u003eWhat does the 50% crossing near 419.1 nm mean for CRI-9?\u003c\/h3\u003e\n\u003cp\u003eIt identifies where this measured curve crosses 50% transmission. It is useful for comparing the spectral transition, but it does not give a fixed color-temperature shift or the total light output from your lamp. For CRI-9, use the band averages above together with your source spectrum.\u003c\/p\u003e\u003c\/section\u003e\u003cp\u003e\u003ca href=\"\/pages\/contact\"\u003e\u003cstrong\u003eDiscuss this filter with KUPO\u003c\/strong\u003e\u003c\/a\u003e - include the product reference, source wavelength, working angle and required dimensions.\u003c\/p\u003e\u003cstyle\u003e#MainContent .ko-reviewed\u003eh2.ko-catalog-description-title{font-size:27px;font-weight:500;line-height:1.4;letter-spacing:-.01em;color:#0c324b;background:#f0f6f9;padding:20px 24px;}#MainContent .ko-reviewed\u003eh2.ko-catalog-description-title+p{border-bottom:0;}@media(max-width:650px){#MainContent .ko-reviewed\u003eh2.ko-catalog-description-title{font-size:24px;}}\u003c\/style\u003e","brand":"KUPO Optics","offers":[{"title":"Color Rendering Improvement Filter \/ Premium (Ra 95+)","offer_id":48516669145343,"sku":"CRI-9","price":0.0,"currency_code":"TWD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0818\/8651\/1359\/files\/cri-9-spectrum.jpg?v=1778712901"},{"product_id":"cri-8","title":"CRI-8 Spectral-shaping filter for color correction","description":"\u003cnav aria-label=\"Product family\"\u003e\u003cp\u003e\u003ca href=\"\/collections\/all-products\"\u003eAll optics\u003c\/a\u003e \/ \u003ca href=\"\/collections\/color-rendering-improvement-cri-filters\"\u003eColor Rendering Correction Filters\u003c\/a\u003e\u003c\/p\u003e\u003c\/nav\u003e\u003cstyle\u003e\n.ko-reviewed{color:#222;font-family:inherit;line-height:1.65;overflow-wrap:anywhere}\n.ko-reviewed *{box-sizing:border-box}.ko-reviewed h2,.ko-reviewed h3{color:#005F96;line-height:1.3}\n.ko-reviewed h2{font-size:24px;margin:0 0 1rem}.ko-reviewed h3{font-size:19px;margin:1.7rem 0 .65rem}\n.ko-reviewed p{margin:.6rem 0 1rem}.ko-reviewed ul{padding-left:1.25rem;margin:.6rem 0 1rem}\n.ko-reviewed li{padding-left:.15rem;margin:.55rem 0}.ko-reviewed .ko-note{border-left:3px solid #c9dae4;padding:.65rem 1rem;background:#f7fafc;font-size:.95em}\n.ko-reviewed a{color:#005F96;text-decoration:underline}\n\n@media(max-width:480px){.ko-reviewed h2{font-size:22px}.ko-reviewed h3{font-size:18px}.ko-reviewed .ko-note{padding:.65rem .8rem}}\n\u003c\/style\u003e\u003csection class=\"ko-reviewed\"\u003e\u003ch2 class=\"ko-catalog-description-title\"\u003eSpectral-shaping filter for color correction (CRI-8)\u003c\/h2\u003e\n\u003cp\u003eCRI-8 is a spectral-shaping filter for color correction. It reshapes the source spectrum by attenuating selected visible wavelengths rather than adding missing colors. Average transmission in the sample is 55.6% over 400-500 nm, 27.5% over 500-600 nm, 62.1% over 600-700 nm. The resulting light output also depends on the lamp spectrum.\u003c\/p\u003e\n\u003ch3\u003eOptical performance\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMeasured wavelength range:\u003c\/strong\u003e 380-800 nm. Performance outside this measured interval is not established by this curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e400-500 nm:\u003c\/strong\u003e Approximately 55.6% average transmission; the range is 13.4-92.8% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e500-600 nm:\u003c\/strong\u003e Approximately 27.5% average transmission; the range is 20.8-67.6% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e600-700 nm:\u003c\/strong\u003e Approximately 62.1% average transmission; the range is 25.7-94% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMeasured edge at 50% transmission:\u003c\/strong\u003e Approximately 472.3 nm. Interpolated absolute-transmission crossing, checked against the factory summary. \u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCustomization:\u003c\/strong\u003e We can customize stock and sample-book designs. Tell us the wavelength response, size and operating conditions you need.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"ko-note\"\u003eThese values come from the measured samples and help you choose a starting design. We will agree the final specification for your order. Custom versions have their own specifications and measured curves.\u003c\/p\u003e\n\u003ch3\u003eApplications to consider\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eLED and discharge-lamp development:\u003c\/strong\u003e Check whether reducing selected peaks improves the balance of your light source. Compare color rendering and luminous output before and after filtering.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eStudio and display lighting:\u003c\/strong\u003e Consider the filter when a measured color imbalance affects the desired appearance of skin tones or objects. Test with the actual source and viewing or camera conditions.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eColor-correction trials:\u003c\/strong\u003e Compare this profile with other correction filters using the same source. A color-rendering score belongs to the resulting light, so it must be measured or calculated for that combination.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eChoosing this filter\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eEvaluate the filter together with the intended light source. Color temperature, tint, color rendering and luminous output depend on that combination.\u003c\/li\u003e\n\u003cli\u003eTell us the size, shape and working angle you need, along with the temperature conditions inside the fixture.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eCustom options\u003c\/h3\u003e\n\u003cp\u003eStart with this stock or sample-book design, then tell us what you need to change. We can discuss the wavelength bands, transmission, blocking, angle, glass material, size and operating conditions with you, and agree a specification for your custom filter.\u003c\/p\u003e\u003c\/section\u003e\u003ch3\u003eTransmission spectrum\u003c\/h3\u003e\u003ciframe src=\"https:\/\/charts.kupooptics.com\/CRI-8.html\" title=\"CRI-8 transmission spectrum with wavelength readout\" loading=\"lazy\" width=\"100%\" height=\"880\" style=\"border:0;width:100%;height:clamp(640px,calc(43vw + 320px),880px);\" referrerpolicy=\"no-referrer-when-downgrade\"\u003e\u003c\/iframe\u003e\u003csection class=\"ko-reviewed ko-product-faq\" aria-label=\"Product questions\"\u003e\u003ch2\u003eQuestions about CRI-8\u003c\/h2\u003e\n\u003ch3\u003eWhat does the spectrum establish about CRI-8 and color rendering?\u003c\/h3\u003e\n\u003cp\u003eThe filter sample averages are 55.6% over 400-500 nm; 27.5% over 500-600 nm; 62.1% over 600-700 nm. They describe transmission, not a color-rendering score. Assess the filtered lamp spectrum or measure the complete lighting setup to find out whether the change helps your application.\u003c\/p\u003e\n\u003ch3\u003eWhat does the 50% crossing near 472.3 nm mean for CRI-8?\u003c\/h3\u003e\n\u003cp\u003eIt identifies where this measured curve crosses 50% transmission. It is useful for comparing the spectral transition, but it does not give a fixed color-temperature shift or the total light output from your lamp. For CRI-8, use the band averages above together with your source spectrum.\u003c\/p\u003e\u003c\/section\u003e\u003cp\u003e\u003ca href=\"\/pages\/contact\"\u003e\u003cstrong\u003eDiscuss this filter with KUPO\u003c\/strong\u003e\u003c\/a\u003e - include the product reference, source wavelength, working angle and required dimensions.\u003c\/p\u003e\u003cstyle\u003e#MainContent .ko-reviewed\u003eh2.ko-catalog-description-title{font-size:27px;font-weight:500;line-height:1.4;letter-spacing:-.01em;color:#0c324b;background:#f0f6f9;padding:20px 24px;}#MainContent .ko-reviewed\u003eh2.ko-catalog-description-title+p{border-bottom:0;}@media(max-width:650px){#MainContent .ko-reviewed\u003eh2.ko-catalog-description-title{font-size:24px;}}\u003c\/style\u003e","brand":"KUPO Optics","offers":[{"title":"Color Rendering Improvement Filter \/ Enhanced (Ra 92+)","offer_id":48516669178111,"sku":"CRI-8","price":0.0,"currency_code":"TWD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0818\/8651\/1359\/files\/cri-8-spectrum.jpg?v=1778712902"},{"product_id":"cri-7","title":"CRI-7 Spectral-shaping filter for color correction","description":"\u003cnav aria-label=\"Product family\"\u003e\u003cp\u003e\u003ca href=\"\/collections\/all-products\"\u003eAll optics\u003c\/a\u003e \/ \u003ca href=\"\/collections\/color-rendering-improvement-cri-filters\"\u003eColor Rendering Correction Filters\u003c\/a\u003e\u003c\/p\u003e\u003c\/nav\u003e\u003cstyle\u003e\n.ko-reviewed{color:#222;font-family:inherit;line-height:1.65;overflow-wrap:anywhere}\n.ko-reviewed *{box-sizing:border-box}.ko-reviewed h2,.ko-reviewed h3{color:#005F96;line-height:1.3}\n.ko-reviewed h2{font-size:24px;margin:0 0 1rem}.ko-reviewed h3{font-size:19px;margin:1.7rem 0 .65rem}\n.ko-reviewed p{margin:.6rem 0 1rem}.ko-reviewed ul{padding-left:1.25rem;margin:.6rem 0 1rem}\n.ko-reviewed li{padding-left:.15rem;margin:.55rem 0}.ko-reviewed .ko-note{border-left:3px solid #c9dae4;padding:.65rem 1rem;background:#f7fafc;font-size:.95em}\n.ko-reviewed a{color:#005F96;text-decoration:underline}\n\n@media(max-width:480px){.ko-reviewed h2{font-size:22px}.ko-reviewed h3{font-size:18px}.ko-reviewed .ko-note{padding:.65rem .8rem}}\n\u003c\/style\u003e\u003csection class=\"ko-reviewed\"\u003e\u003ch2 class=\"ko-catalog-description-title\"\u003eSpectral-shaping filter for color correction (CRI-7)\u003c\/h2\u003e\n\u003cp\u003eCRI-7 is a spectral-shaping filter for color correction. It reshapes the source spectrum by attenuating selected visible wavelengths rather than adding missing colors. Average transmission in the sample is 44.9% over 400-500 nm, 25.3% over 500-600 nm, 79% over 600-700 nm. The resulting light output also depends on the lamp spectrum.\u003c\/p\u003e\n\u003ch3\u003eOptical performance\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMeasured wavelength range:\u003c\/strong\u003e 380-800 nm. Performance outside this measured interval is not established by this curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e400-500 nm:\u003c\/strong\u003e Approximately 44.9% average transmission; the range is 7.1-88.7% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e500-600 nm:\u003c\/strong\u003e Approximately 25.3% average transmission; the range is 17.7-40.6% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e600-700 nm:\u003c\/strong\u003e Approximately 79% average transmission; the range is 40.6-95.5% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMeasured edge at 50% transmission:\u003c\/strong\u003e Approximately 462.9 nm. Interpolated absolute-transmission crossing, checked against the factory summary. \u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCustomization:\u003c\/strong\u003e We can customize stock and sample-book designs. Tell us the wavelength response, size and operating conditions you need.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"ko-note\"\u003eThese values come from the measured samples and help you choose a starting design. We will agree the final specification for your order. Custom versions have their own specifications and measured curves.\u003c\/p\u003e\n\u003ch3\u003eApplications to consider\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eLED and discharge-lamp development:\u003c\/strong\u003e Check whether reducing selected peaks improves the balance of your light source. Compare color rendering and luminous output before and after filtering.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eStudio and display lighting:\u003c\/strong\u003e Consider the filter when a measured color imbalance affects the desired appearance of skin tones or objects. Test with the actual source and viewing or camera conditions.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eColor-correction trials:\u003c\/strong\u003e Compare this profile with other correction filters using the same source. A color-rendering score belongs to the resulting light, so it must be measured or calculated for that combination.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eChoosing this filter\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eEvaluate the filter together with the intended light source. Color temperature, tint, color rendering and luminous output depend on that combination.\u003c\/li\u003e\n\u003cli\u003eTell us the size, shape and working angle you need, along with the temperature conditions inside the fixture.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eCustom options\u003c\/h3\u003e\n\u003cp\u003eStart with this stock or sample-book design, then tell us what you need to change. We can discuss the wavelength bands, transmission, blocking, angle, glass material, size and operating conditions with you, and agree a specification for your custom filter.\u003c\/p\u003e\u003c\/section\u003e\u003ch3\u003eTransmission spectrum\u003c\/h3\u003e\u003ciframe src=\"https:\/\/charts.kupooptics.com\/CRI-7.html\" title=\"CRI-7 transmission spectrum with wavelength readout\" loading=\"lazy\" width=\"100%\" height=\"880\" style=\"border:0;width:100%;height:clamp(640px,calc(43vw + 320px),880px);\" referrerpolicy=\"no-referrer-when-downgrade\"\u003e\u003c\/iframe\u003e\u003csection class=\"ko-reviewed ko-product-faq\" aria-label=\"Product questions\"\u003e\u003ch2\u003eQuestions about CRI-7\u003c\/h2\u003e\n\u003ch3\u003eHow do I judge whether CRI-7 suits my light source?\u003c\/h3\u003e\n\u003cp\u003eThe filter sample averages are 44.9% over 400-500 nm; 25.3% over 500-600 nm; 79% over 600-700 nm. They describe transmission, not a color-rendering score. Assess the filtered lamp spectrum or measure the complete lighting setup to find out whether the change helps your application.\u003c\/p\u003e\n\u003ch3\u003eWhat does the 50% crossing near 462.9 nm mean for CRI-7?\u003c\/h3\u003e\n\u003cp\u003eIt identifies where this measured curve crosses 50% transmission. It is useful for comparing the spectral transition, but it does not give a fixed color-temperature shift or the total light output from your lamp. For CRI-7, use the band averages above together with your source spectrum.\u003c\/p\u003e\u003c\/section\u003e\u003cp\u003e\u003ca href=\"\/pages\/contact\"\u003e\u003cstrong\u003eDiscuss this filter with KUPO\u003c\/strong\u003e\u003c\/a\u003e - include the product reference, source wavelength, working angle and required dimensions.\u003c\/p\u003e\u003cstyle\u003e#MainContent .ko-reviewed\u003eh2.ko-catalog-description-title{font-size:27px;font-weight:500;line-height:1.4;letter-spacing:-.01em;color:#0c324b;background:#f0f6f9;padding:20px 24px;}#MainContent .ko-reviewed\u003eh2.ko-catalog-description-title+p{border-bottom:0;}@media(max-width:650px){#MainContent .ko-reviewed\u003eh2.ko-catalog-description-title{font-size:24px;}}\u003c\/style\u003e","brand":"KUPO Optics","offers":[{"title":"Color Rendering Improvement Filter \/ Premium (Ra 95+)","offer_id":48516669210879,"sku":"CRI-7","price":0.0,"currency_code":"TWD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0818\/8651\/1359\/files\/cri-7-spectrum.jpg?v=1778712903"},{"product_id":"cri-4","title":"CRI-4 Spectral-shaping filter for color correction","description":"\u003cnav aria-label=\"Product family\"\u003e\u003cp\u003e\u003ca href=\"\/collections\/all-products\"\u003eAll optics\u003c\/a\u003e \/ \u003ca href=\"\/collections\/color-rendering-improvement-cri-filters\"\u003eColor Rendering Correction Filters\u003c\/a\u003e\u003c\/p\u003e\u003c\/nav\u003e\u003cstyle\u003e\n.ko-reviewed{color:#222;font-family:inherit;line-height:1.65;overflow-wrap:anywhere}\n.ko-reviewed *{box-sizing:border-box}.ko-reviewed h2,.ko-reviewed h3{color:#005F96;line-height:1.3}\n.ko-reviewed h2{font-size:24px;margin:0 0 1rem}.ko-reviewed h3{font-size:19px;margin:1.7rem 0 .65rem}\n.ko-reviewed p{margin:.6rem 0 1rem}.ko-reviewed ul{padding-left:1.25rem;margin:.6rem 0 1rem}\n.ko-reviewed li{padding-left:.15rem;margin:.55rem 0}.ko-reviewed .ko-note{border-left:3px solid #c9dae4;padding:.65rem 1rem;background:#f7fafc;font-size:.95em}\n.ko-reviewed a{color:#005F96;text-decoration:underline}\n\n@media(max-width:480px){.ko-reviewed h2{font-size:22px}.ko-reviewed h3{font-size:18px}.ko-reviewed .ko-note{padding:.65rem .8rem}}\n\u003c\/style\u003e\u003csection class=\"ko-reviewed\"\u003e\u003ch2 class=\"ko-catalog-description-title\"\u003eSpectral-shaping filter for color correction (CRI-4)\u003c\/h2\u003e\n\u003cp\u003eCRI-4 is a spectral-shaping filter for color correction. It reshapes the source spectrum by attenuating selected visible wavelengths rather than adding missing colors. Average transmission in the sample is 73.4% over 400-500 nm, 56% over 500-600 nm, 90.1% over 600-700 nm. The resulting light output also depends on the lamp spectrum.\u003c\/p\u003e\n\u003ch3\u003eOptical performance\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMeasured wavelength range:\u003c\/strong\u003e 380-800 nm. Performance outside this measured interval is not established by this curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e400-500 nm:\u003c\/strong\u003e Approximately 73.4% average transmission; the range is 40.7-94.1% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e500-600 nm:\u003c\/strong\u003e Approximately 56% average transmission; the range is 33.7-90% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e600-700 nm:\u003c\/strong\u003e Approximately 90.1% average transmission; the range is 60.2-95.9% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMeasured edge at 70% transmission:\u003c\/strong\u003e Approximately 529.4 nm. Interpolated absolute-transmission crossing, checked against the factory summary. \u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCustomization:\u003c\/strong\u003e We can customize stock and sample-book designs. Tell us the wavelength response, size and operating conditions you need.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"ko-note\"\u003eThese values come from the measured samples and help you choose a starting design. We will agree the final specification for your order. Custom versions have their own specifications and measured curves.\u003c\/p\u003e\n\u003ch3\u003eApplications to consider\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eLED and discharge-lamp development:\u003c\/strong\u003e Check whether reducing selected peaks improves the balance of your light source. Compare color rendering and luminous output before and after filtering.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eStudio and display lighting:\u003c\/strong\u003e Consider the filter when a measured color imbalance affects the desired appearance of skin tones or objects. Test with the actual source and viewing or camera conditions.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eColor-correction trials:\u003c\/strong\u003e Compare this profile with other correction filters using the same source. A color-rendering score belongs to the resulting light, so it must be measured or calculated for that combination.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eChoosing this filter\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eEvaluate the filter together with the intended light source. Color temperature, tint, color rendering and luminous output depend on that combination.\u003c\/li\u003e\n\u003cli\u003eTell us the size, shape and working angle you need, along with the temperature conditions inside the fixture.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eCustom options\u003c\/h3\u003e\n\u003cp\u003eStart with this stock or sample-book design, then tell us what you need to change. We can discuss the wavelength bands, transmission, blocking, angle, glass material, size and operating conditions with you, and agree a specification for your custom filter.\u003c\/p\u003e\u003c\/section\u003e\u003ch3\u003eTransmission spectrum\u003c\/h3\u003e\u003ciframe src=\"https:\/\/charts.kupooptics.com\/CRI-4.html\" title=\"CRI-4 transmission spectrum with wavelength readout\" loading=\"lazy\" width=\"100%\" height=\"880\" style=\"border:0;width:100%;height:clamp(640px,calc(43vw + 320px),880px);\" referrerpolicy=\"no-referrer-when-downgrade\"\u003e\u003c\/iframe\u003e\u003csection class=\"ko-reviewed ko-product-faq\" aria-label=\"Product questions\"\u003e\u003ch2\u003eQuestions about CRI-4\u003c\/h2\u003e\n\u003ch3\u003eCan CRI-4 guarantee a higher color-rendering index?\u003c\/h3\u003e\n\u003cp\u003eThe filter sample averages are 73.4% over 400-500 nm; 56% over 500-600 nm; 90.1% over 600-700 nm. They describe transmission, not a color-rendering score. Assess the filtered lamp spectrum or measure the complete lighting setup to find out whether the change helps your application.\u003c\/p\u003e\n\u003ch3\u003eWhat does the 70% crossing near 529.4 nm mean for CRI-4?\u003c\/h3\u003e\n\u003cp\u003eIt identifies where this measured curve crosses 70% transmission. It is useful for comparing the spectral transition, but it does not give a fixed color-temperature shift or the total light output from your lamp. For CRI-4, use the band averages above together with your source spectrum.\u003c\/p\u003e\u003c\/section\u003e\u003cp\u003e\u003ca href=\"\/pages\/contact\"\u003e\u003cstrong\u003eDiscuss this filter with KUPO\u003c\/strong\u003e\u003c\/a\u003e - include the product reference, source wavelength, working angle and required dimensions.\u003c\/p\u003e\u003cstyle\u003e#MainContent .ko-reviewed\u003eh2.ko-catalog-description-title{font-size:27px;font-weight:500;line-height:1.4;letter-spacing:-.01em;color:#0c324b;background:#f0f6f9;padding:20px 24px;}#MainContent .ko-reviewed\u003eh2.ko-catalog-description-title+p{border-bottom:0;}@media(max-width:650px){#MainContent .ko-reviewed\u003eh2.ko-catalog-description-title{font-size:24px;}}\u003c\/style\u003e","brand":"KUPO Optics","offers":[{"title":"Color Rendering Improvement Filter \/ Enhanced (Ra 92+)","offer_id":48516669243647,"sku":"CRI-4","price":0.0,"currency_code":"TWD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0818\/8651\/1359\/files\/cri-4-spectrum.jpg?v=1778712904"},{"product_id":"cri-1","title":"CRI-1 Spectral-shaping filter for color correction","description":"\u003cnav aria-label=\"Product family\"\u003e\u003cp\u003e\u003ca href=\"\/collections\/all-products\"\u003eAll optics\u003c\/a\u003e \/ \u003ca href=\"\/collections\/color-rendering-improvement-cri-filters\"\u003eColor Rendering Correction Filters\u003c\/a\u003e\u003c\/p\u003e\u003c\/nav\u003e\u003cstyle\u003e\n.ko-reviewed{color:#222;font-family:inherit;line-height:1.65;overflow-wrap:anywhere}\n.ko-reviewed *{box-sizing:border-box}.ko-reviewed h2,.ko-reviewed h3{color:#005F96;line-height:1.3}\n.ko-reviewed h2{font-size:24px;margin:0 0 1rem}.ko-reviewed h3{font-size:19px;margin:1.7rem 0 .65rem}\n.ko-reviewed p{margin:.6rem 0 1rem}.ko-reviewed ul{padding-left:1.25rem;margin:.6rem 0 1rem}\n.ko-reviewed li{padding-left:.15rem;margin:.55rem 0}.ko-reviewed .ko-note{border-left:3px solid #c9dae4;padding:.65rem 1rem;background:#f7fafc;font-size:.95em}\n.ko-reviewed a{color:#005F96;text-decoration:underline}\n\n@media(max-width:480px){.ko-reviewed h2{font-size:22px}.ko-reviewed h3{font-size:18px}.ko-reviewed .ko-note{padding:.65rem .8rem}}\n\u003c\/style\u003e\u003csection class=\"ko-reviewed\"\u003e\u003ch2 class=\"ko-catalog-description-title\"\u003eSpectral-shaping filter for color correction (CRI-1)\u003c\/h2\u003e\n\u003cp\u003eCRI-1 is a spectral-shaping filter for color correction. It reshapes the source spectrum by attenuating selected visible wavelengths rather than adding missing colors. Average transmission in the sample is 55% over 400-500 nm, 53.8% over 500-600 nm, 83.9% over 600-700 nm. The resulting light output also depends on the lamp spectrum.\u003c\/p\u003e\n\u003ch3\u003eOptical performance\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMeasured wavelength range:\u003c\/strong\u003e 380-800 nm. Performance outside this measured interval is not established by this curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e400-500 nm:\u003c\/strong\u003e Approximately 55% average transmission; the range is 21.2-91.5% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e500-600 nm:\u003c\/strong\u003e Approximately 53.8% average transmission; the range is 50.3-72% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e600-700 nm:\u003c\/strong\u003e Approximately 83.9% average transmission; the range is 58.1-92.7% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMeasured edge at 50% transmission:\u003c\/strong\u003e Approximately 448.8 nm. Interpolated absolute-transmission crossing, checked against the factory summary. \u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCustomization:\u003c\/strong\u003e We can customize stock and sample-book designs. Tell us the wavelength response, size and operating conditions you need.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"ko-note\"\u003eThese values come from the measured samples and help you choose a starting design. We will agree the final specification for your order. Custom versions have their own specifications and measured curves.\u003c\/p\u003e\n\u003ch3\u003eApplications to consider\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eLED and discharge-lamp development:\u003c\/strong\u003e Check whether reducing selected peaks improves the balance of your light source. Compare color rendering and luminous output before and after filtering.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eStudio and display lighting:\u003c\/strong\u003e Consider the filter when a measured color imbalance affects the desired appearance of skin tones or objects. Test with the actual source and viewing or camera conditions.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eColor-correction trials:\u003c\/strong\u003e Compare this profile with other correction filters using the same source. A color-rendering score belongs to the resulting light, so it must be measured or calculated for that combination.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eChoosing this filter\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eEvaluate the filter together with the intended light source. Color temperature, tint, color rendering and luminous output depend on that combination.\u003c\/li\u003e\n\u003cli\u003eTell us the size, shape and working angle you need, along with the temperature conditions inside the fixture.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eCustom options\u003c\/h3\u003e\n\u003cp\u003eStart with this stock or sample-book design, then tell us what you need to change. We can discuss the wavelength bands, transmission, blocking, angle, glass material, size and operating conditions with you, and agree a specification for your custom filter.\u003c\/p\u003e\u003c\/section\u003e\u003ch3\u003eTransmission spectrum\u003c\/h3\u003e\u003ciframe src=\"https:\/\/charts.kupooptics.com\/CRI-1.html\" title=\"CRI-1 transmission spectrum with wavelength readout\" loading=\"lazy\" width=\"100%\" height=\"880\" style=\"border:0;width:100%;height:clamp(640px,calc(43vw + 320px),880px);\" referrerpolicy=\"no-referrer-when-downgrade\"\u003e\u003c\/iframe\u003e\u003csection class=\"ko-reviewed ko-product-faq\" aria-label=\"Product questions\"\u003e\u003ch2\u003eQuestions about CRI-1\u003c\/h2\u003e\n\u003ch3\u003eHow do I judge whether CRI-1 suits my light source?\u003c\/h3\u003e\n\u003cp\u003eThe filter sample averages are 55% over 400-500 nm; 53.8% over 500-600 nm; 83.9% over 600-700 nm. They describe transmission, not a color-rendering score. Assess the filtered lamp spectrum or measure the complete lighting setup to find out whether the change helps your application.\u003c\/p\u003e\n\u003ch3\u003eWhat does the 50% crossing near 448.8 nm mean for CRI-1?\u003c\/h3\u003e\n\u003cp\u003eIt identifies where this measured curve crosses 50% transmission. It is useful for comparing the spectral transition, but it does not give a fixed color-temperature shift or the total light output from your lamp. For CRI-1, use the band averages above together with your source spectrum.\u003c\/p\u003e\u003c\/section\u003e\u003cp\u003e\u003ca href=\"\/pages\/contact\"\u003e\u003cstrong\u003eDiscuss this filter with KUPO\u003c\/strong\u003e\u003c\/a\u003e - include the product reference, source wavelength, working angle and required dimensions.\u003c\/p\u003e\u003cstyle\u003e#MainContent .ko-reviewed\u003eh2.ko-catalog-description-title{font-size:27px;font-weight:500;line-height:1.4;letter-spacing:-.01em;color:#0c324b;background:#f0f6f9;padding:20px 24px;}#MainContent .ko-reviewed\u003eh2.ko-catalog-description-title+p{border-bottom:0;}@media(max-width:650px){#MainContent .ko-reviewed\u003eh2.ko-catalog-description-title{font-size:24px;}}\u003c\/style\u003e","brand":"KUPO Optics","offers":[{"title":"Color Rendering Improvement Filter \/ Enhanced (Ra 92+)","offer_id":48516669276415,"sku":"CRI-1","price":0.0,"currency_code":"TWD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0818\/8651\/1359\/files\/cri-1-spectrum.jpg?v=1778712905"}],"url":"https:\/\/kupooptics.com\/collections\/color-rendering-improvement-cri-filters.oembed","provider":"KUPO Optics","version":"1.0","type":"link"}