{"title":"Color Temperature Blue Filters","description":"\u003cp\u003eShift the balance of a light source toward a cooler appearance by selectively changing its spectrum. Compare the reference curves to select an appropriate cooling response.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow to choose:\u003c\/strong\u003e Final color temperature and light output depend on the incident source. Confirm the source spectrum and desired correction instead of selecting from the product code alone.\u003c\/p\u003e","products":[{"product_id":"ctb-014","title":"CTB-014 Cooling color-correction filter","description":"\u003cnav aria-label=\"Product family\"\u003e\u003cp\u003e\u003ca href=\"\/collections\/all-products\"\u003eAll optics\u003c\/a\u003e \/ \u003ca href=\"\/collections\/color-temperature-blue-cooling-filter\"\u003eColor Temperature Blue 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\"\u003eCooling color-correction filter (CTB-014)\u003c\/h2\u003e\n\u003cp\u003eCTB-014 is a cooling color-correction filter. It transmits more of the blue region than the red region. This can give a warm light source a cooler balance. Average transmission in the sample is 78.7% over 400-500 nm, 60.4% over 500-600 nm, 53.4% 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 78.7% average transmission; the range is 68.5-85.5% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e500-600 nm:\u003c\/strong\u003e Approximately 60.4% average transmission; the range is 54.7-68.5% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e600-700 nm:\u003c\/strong\u003e Approximately 53.4% average transmission; the range is 52.8-54.7% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMeasured edge at 70% transmission:\u003c\/strong\u003e Approximately 493.9 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\u003eFilm and broadcast lighting:\u003c\/strong\u003e Consider cooling a warm source toward the color of another fixture. Check the resulting color temperature and tint with the actual lamp and camera.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eStage color shaping:\u003c\/strong\u003e Try it when you want a bluer lighting effect. Account for the transmitted red and green content rather than expecting monochromatic blue.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLighting-fixture development:\u003c\/strong\u003e Compare the spectrum and brightness of the filtered light with other correction filters before choosing a strength.\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\/CTB-014.html\" title=\"CTB-014 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 CTB-014\u003c\/h2\u003e\n\u003ch3\u003eWhy does the whole curve matter for CTB-014?\u003c\/h3\u003e\n\u003cp\u003eThe measured averages are 78.7% over 400-500 nm; 60.4% over 500-600 nm; 53.4% over 600-700 nm. They show how the filter weights different parts of the visible spectrum; the resulting color depends on which wavelengths your lamp supplies.\u003c\/p\u003e\n\u003ch3\u003eWhat does the 70% crossing near 493.9 nm mean for CTB-014?\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 CTB-014, 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 Temperature Blue (Cooling) Filter \/ 1\/4 CTB","offer_id":48516669309183,"sku":"CTB-014","price":0.0,"currency_code":"TWD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0818\/8651\/1359\/files\/ctb-014-spectrum.jpg?v=1778712905"},{"product_id":"ctb-013","title":"CTB-013 Cooling color-correction filter","description":"\u003cnav aria-label=\"Product family\"\u003e\u003cp\u003e\u003ca href=\"\/collections\/all-products\"\u003eAll optics\u003c\/a\u003e \/ \u003ca href=\"\/collections\/color-temperature-blue-cooling-filter\"\u003eColor Temperature Blue 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\"\u003eCooling color-correction filter (CTB-013)\u003c\/h2\u003e\n\u003cp\u003eCTB-013 is a cooling color-correction filter. It transmits more of the blue region than the red region. This can give a warm light source a cooler balance. Average transmission in the sample is 87.3% over 400-500 nm, 63.2% over 500-600 nm, 54.5% 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 87.3% average transmission; the range is 82.6-90.5% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e500-600 nm:\u003c\/strong\u003e Approximately 63.2% average transmission; the range is 51-82.6% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e600-700 nm:\u003c\/strong\u003e Approximately 54.5% average transmission; the range is 50.5-63.8% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMeasured edge at 70% transmission:\u003c\/strong\u003e Approximately 528.0 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\u003eFilm and broadcast lighting:\u003c\/strong\u003e Consider cooling a warm source toward the color of another fixture. Check the resulting color temperature and tint with the actual lamp and camera.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eStage color shaping:\u003c\/strong\u003e Try it when you want a bluer lighting effect. Account for the transmitted red and green content rather than expecting monochromatic blue.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLighting-fixture development:\u003c\/strong\u003e Compare the spectrum and brightness of the filtered light with other correction filters before choosing a strength.\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\/CTB-013.html\" title=\"CTB-013 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 CTB-013\u003c\/h2\u003e\n\u003ch3\u003eWhat should I look at when choosing CTB-013 for cooling?\u003c\/h3\u003e\n\u003cp\u003eThe measured averages are 87.3% over 400-500 nm; 63.2% over 500-600 nm; 54.5% over 600-700 nm. They show how the filter weights different parts of the visible spectrum; the resulting color depends on which wavelengths your lamp supplies.\u003c\/p\u003e\n\u003ch3\u003eWhat does the 70% crossing near 528.0 nm mean for CTB-013?\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 CTB-013, 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 Temperature Blue (Cooling) Filter \/ 1\/4 CTB","offer_id":48516669341951,"sku":"CTB-013","price":0.0,"currency_code":"TWD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0818\/8651\/1359\/files\/ctb-013-spectrum.jpg?v=1778712906"},{"product_id":"ctb-012","title":"CTB-012 Cooling color-correction filter","description":"\u003cnav aria-label=\"Product family\"\u003e\u003cp\u003e\u003ca href=\"\/collections\/all-products\"\u003eAll optics\u003c\/a\u003e \/ \u003ca href=\"\/collections\/color-temperature-blue-cooling-filter\"\u003eColor Temperature Blue 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\"\u003eCooling color-correction filter (CTB-012)\u003c\/h2\u003e\n\u003cp\u003eCTB-012 is a cooling color-correction filter. It transmits more of the blue region than the red region. This can give a warm light source a cooler balance. Average transmission in the sample is 80.2% over 400-500 nm, 61.7% over 500-600 nm, 56.7% 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 80.2% average transmission; the range is 70.4-87.1% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e500-600 nm:\u003c\/strong\u003e Approximately 61.7% average transmission; the range is 57.7-70.4% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e600-700 nm:\u003c\/strong\u003e Approximately 56.7% average transmission; the range is 56.3-57.8% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMeasured edge at 70% transmission:\u003c\/strong\u003e Approximately 501.4 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\u003eFilm and broadcast lighting:\u003c\/strong\u003e Consider cooling a warm source toward the color of another fixture. Check the resulting color temperature and tint with the actual lamp and camera.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eStage color shaping:\u003c\/strong\u003e Try it when you want a bluer lighting effect. Account for the transmitted red and green content rather than expecting monochromatic blue.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLighting-fixture development:\u003c\/strong\u003e Compare the spectrum and brightness of the filtered light with other correction filters before choosing a strength.\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\/CTB-012.html\" title=\"CTB-012 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 CTB-012\u003c\/h2\u003e\n\u003ch3\u003eHow does CTB-012 balance the visible wavelengths?\u003c\/h3\u003e\n\u003cp\u003eThe measured averages are 80.2% over 400-500 nm; 61.7% over 500-600 nm; 56.7% over 600-700 nm. They show how the filter weights different parts of the visible spectrum; the resulting color depends on which wavelengths your lamp supplies.\u003c\/p\u003e\n\u003ch3\u003eWhat does the 70% crossing near 501.4 nm mean for CTB-012?\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 CTB-012, 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 Temperature Blue (Cooling) Filter \/ 1\/4 CTB","offer_id":48516669374719,"sku":"CTB-012","price":0.0,"currency_code":"TWD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0818\/8651\/1359\/files\/ctb-012-spectrum.jpg?v=1778712907"},{"product_id":"ctb-011","title":"CTB-011 Cooling color-correction filter","description":"\u003cnav aria-label=\"Product family\"\u003e\u003cp\u003e\u003ca href=\"\/collections\/all-products\"\u003eAll optics\u003c\/a\u003e \/ \u003ca href=\"\/collections\/color-temperature-blue-cooling-filter\"\u003eColor Temperature Blue 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\"\u003eCooling color-correction filter (CTB-011)\u003c\/h2\u003e\n\u003cp\u003eCTB-011 is a cooling color-correction filter. It transmits more of the blue region than the red region. This can give a warm light source a cooler balance. Average transmission in the sample is 48.1% over 400-500 nm, 20.6% over 500-600 nm, 24.6% 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 48.1% average transmission; the range is 21.8-89.9% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e500-600 nm:\u003c\/strong\u003e Approximately 20.6% average transmission; the range is 18-22.4% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e600-700 nm:\u003c\/strong\u003e Approximately 24.6% average transmission; the range is 18-38.2% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMeasured edge at 50% transmission:\u003c\/strong\u003e Approximately 468.9 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\u003eFilm and broadcast lighting:\u003c\/strong\u003e Consider cooling a warm source toward the color of another fixture. Check the resulting color temperature and tint with the actual lamp and camera.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eStage color shaping:\u003c\/strong\u003e Try it when you want a bluer lighting effect. Account for the transmitted red and green content rather than expecting monochromatic blue.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLighting-fixture development:\u003c\/strong\u003e Compare the spectrum and brightness of the filtered light with other correction filters before choosing a strength.\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\/CTB-011.html\" title=\"CTB-011 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 CTB-011\u003c\/h2\u003e\n\u003ch3\u003eWhy does the whole curve matter for CTB-011?\u003c\/h3\u003e\n\u003cp\u003eThe measured averages are 48.1% over 400-500 nm; 20.6% over 500-600 nm; 24.6% over 600-700 nm. They show how the filter weights different parts of the visible spectrum; the resulting color depends on which wavelengths your lamp supplies.\u003c\/p\u003e\n\u003ch3\u003eWhat does the 50% crossing near 468.9 nm mean for CTB-011?\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 CTB-011, 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 Temperature Blue (Cooling) Filter \/ Full CTB","offer_id":48516669407487,"sku":"CTB-011","price":0.0,"currency_code":"TWD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0818\/8651\/1359\/files\/ctb-011-spectrum.jpg?v=1778712908"},{"product_id":"ctb-010","title":"CTB-010 Cooling color-correction filter","description":"\u003cnav aria-label=\"Product family\"\u003e\u003cp\u003e\u003ca href=\"\/collections\/all-products\"\u003eAll optics\u003c\/a\u003e \/ \u003ca href=\"\/collections\/color-temperature-blue-cooling-filter\"\u003eColor Temperature Blue 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\"\u003eCooling color-correction filter (CTB-010)\u003c\/h2\u003e\n\u003cp\u003eCTB-010 is a cooling color-correction filter. It transmits more of the blue region than the red region. This can give a warm light source a cooler balance. Average transmission in the sample is 79.3% over 400-500 nm, 54.3% over 500-600 nm, 56.5% 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 79.3% average transmission; the range is 53.1-95.4% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e500-600 nm:\u003c\/strong\u003e Approximately 54.3% average transmission; the range is 52.3-57.2% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e600-700 nm:\u003c\/strong\u003e Approximately 56.5% average transmission; the range is 49.4-59% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMeasured edge at 70% transmission:\u003c\/strong\u003e Approximately 465.6 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\u003eFilm and broadcast lighting:\u003c\/strong\u003e Consider cooling a warm source toward the color of another fixture. Check the resulting color temperature and tint with the actual lamp and camera.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eStage color shaping:\u003c\/strong\u003e Try it when you want a bluer lighting effect. Account for the transmitted red and green content rather than expecting monochromatic blue.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLighting-fixture development:\u003c\/strong\u003e Compare the spectrum and brightness of the filtered light with other correction filters before choosing a strength.\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\/CTB-010.html\" title=\"CTB-010 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 CTB-010\u003c\/h2\u003e\n\u003ch3\u003eWhat should I look at when choosing CTB-010 for cooling?\u003c\/h3\u003e\n\u003cp\u003eThe measured averages are 79.3% over 400-500 nm; 54.3% over 500-600 nm; 56.5% over 600-700 nm. They show how the filter weights different parts of the visible spectrum; the resulting color depends on which wavelengths your lamp supplies.\u003c\/p\u003e\n\u003ch3\u003eWhat does the 70% crossing near 465.6 nm mean for CTB-010?\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 CTB-010, 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 Temperature Blue (Cooling) Filter \/ 1\/2 CTB","offer_id":48516669440255,"sku":"CTB-010","price":0.0,"currency_code":"TWD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0818\/8651\/1359\/files\/ctb-010-spectrum.jpg?v=1778712909"},{"product_id":"ctb-009","title":"CTB-009 Cooling color-correction filter","description":"\u003cnav aria-label=\"Product family\"\u003e\u003cp\u003e\u003ca href=\"\/collections\/all-products\"\u003eAll optics\u003c\/a\u003e \/ \u003ca href=\"\/collections\/color-temperature-blue-cooling-filter\"\u003eColor Temperature Blue 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\"\u003eCooling color-correction filter (CTB-009)\u003c\/h2\u003e\n\u003cp\u003eCTB-009 is a cooling color-correction filter. It transmits more of the blue region than the red region. This can give a warm light source a cooler balance. Average transmission in the sample is 76.8% over 400-500 nm, 53.4% over 500-600 nm, 48.9% 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 76.8% average transmission; the range is 65.1-86.5% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e500-600 nm:\u003c\/strong\u003e Approximately 53.4% average transmission; the range is 48.5-65.1% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e600-700 nm:\u003c\/strong\u003e Approximately 48.9% average transmission; the range is 48.5-49.5% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMeasured edge at 70% transmission:\u003c\/strong\u003e Approximately 484.2 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\u003eFilm and broadcast lighting:\u003c\/strong\u003e Consider cooling a warm source toward the color of another fixture. Check the resulting color temperature and tint with the actual lamp and camera.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eStage color shaping:\u003c\/strong\u003e Try it when you want a bluer lighting effect. Account for the transmitted red and green content rather than expecting monochromatic blue.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLighting-fixture development:\u003c\/strong\u003e Compare the spectrum and brightness of the filtered light with other correction filters before choosing a strength.\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\/CTB-009.html\" title=\"CTB-009 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 CTB-009\u003c\/h2\u003e\n\u003ch3\u003eHow does CTB-009 balance the visible wavelengths?\u003c\/h3\u003e\n\u003cp\u003eThe measured averages are 76.8% over 400-500 nm; 53.4% over 500-600 nm; 48.9% over 600-700 nm. They show how the filter weights different parts of the visible spectrum; the resulting color depends on which wavelengths your lamp supplies.\u003c\/p\u003e\n\u003ch3\u003eWhat does the 70% crossing near 484.2 nm mean for CTB-009?\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 CTB-009, 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 Temperature Blue (Cooling) Filter \/ 1\/2 CTB","offer_id":48516669473023,"sku":"CTB-009","price":0.0,"currency_code":"TWD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0818\/8651\/1359\/files\/ctb-009-spectrum.jpg?v=1778712909"},{"product_id":"ctb-008","title":"CTB-008 Cooling color-correction filter","description":"\u003cnav aria-label=\"Product family\"\u003e\u003cp\u003e\u003ca href=\"\/collections\/all-products\"\u003eAll optics\u003c\/a\u003e \/ \u003ca href=\"\/collections\/color-temperature-blue-cooling-filter\"\u003eColor Temperature Blue 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\"\u003eCooling color-correction filter (CTB-008)\u003c\/h2\u003e\n\u003cp\u003eCTB-008 is a cooling color-correction filter. It transmits more of the blue region than the red region. This can give a warm light source a cooler balance. Average transmission in the sample is 81% over 400-500 nm, 65.3% over 500-600 nm, 65% 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 81% average transmission; the range is 68.8-87.2% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e500-600 nm:\u003c\/strong\u003e Approximately 65.3% average transmission; the range is 64.4-68.8% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e600-700 nm:\u003c\/strong\u003e Approximately 65% average transmission; the range is 64.8-65.2% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMeasured edge at 70% transmission:\u003c\/strong\u003e Approximately 494.6 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\u003eFilm and broadcast lighting:\u003c\/strong\u003e Consider cooling a warm source toward the color of another fixture. Check the resulting color temperature and tint with the actual lamp and camera.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eStage color shaping:\u003c\/strong\u003e Try it when you want a bluer lighting effect. Account for the transmitted red and green content rather than expecting monochromatic blue.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLighting-fixture development:\u003c\/strong\u003e Compare the spectrum and brightness of the filtered light with other correction filters before choosing a strength.\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\/CTB-008.html\" title=\"CTB-008 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 CTB-008\u003c\/h2\u003e\n\u003ch3\u003eWhy does the whole curve matter for CTB-008?\u003c\/h3\u003e\n\u003cp\u003eThe measured averages are 81% over 400-500 nm; 65.3% over 500-600 nm; 65% over 600-700 nm. They show how the filter weights different parts of the visible spectrum; the resulting color depends on which wavelengths your lamp supplies.\u003c\/p\u003e\n\u003ch3\u003eWhat does the 70% crossing near 494.6 nm mean for CTB-008?\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 CTB-008, 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 Temperature Blue (Cooling) Filter \/ 1\/4 CTB","offer_id":48516669505791,"sku":"CTB-008","price":0.0,"currency_code":"TWD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0818\/8651\/1359\/files\/ctb-008-spectrum.jpg?v=1778712910"},{"product_id":"ctb-200","title":"CTB-200 Cooling color-correction filter","description":"\u003cnav aria-label=\"Product family\"\u003e\u003cp\u003e\u003ca href=\"\/collections\/all-products\"\u003eAll optics\u003c\/a\u003e \/ \u003ca href=\"\/collections\/color-temperature-blue-cooling-filter\"\u003eColor Temperature Blue 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\"\u003eCooling color-correction filter (CTB-200)\u003c\/h2\u003e\n\u003cp\u003eCTB-200 is a cooling color-correction filter. It transmits more of the blue region than the red region. This can give a warm light source a cooler balance. Average transmission in the sample is 94.9% over 400-500 nm, 30.2% over 500-600 nm, 17.4% 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 380-780 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 94.9% average transmission; the range is 87.4-95.7% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e500-600 nm:\u003c\/strong\u003e Approximately 30.2% average transmission; the range is 11.5-87.4% in the measured curve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e600-700 nm:\u003c\/strong\u003e Approximately 17.4% average transmission; the range is 12-22.6% in the measured curve.\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\u003eFilm and broadcast lighting:\u003c\/strong\u003e Consider cooling a warm source toward the color of another fixture. Check the resulting color temperature and tint with the actual lamp and camera.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eStage color shaping:\u003c\/strong\u003e Try it when you want a bluer lighting effect. Account for the transmitted red and green content rather than expecting monochromatic blue.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLighting-fixture development:\u003c\/strong\u003e Compare the spectrum and brightness of the filtered light with other correction filters before choosing a strength.\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\/CTB-200.html\" title=\"CTB-200 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 CTB-200\u003c\/h2\u003e\n\u003ch3\u003eHow does CTB-200 balance the visible wavelengths?\u003c\/h3\u003e\n\u003cp\u003eThe measured averages are 94.9% over 400-500 nm; 30.2% over 500-600 nm; 17.4% over 600-700 nm. They show how the filter weights different parts of the visible spectrum; the resulting color depends on which wavelengths your lamp supplies.\u003c\/p\u003e\n\u003ch3\u003eCan I predict the brightness after CTB-200 from these three averages?\u003c\/h3\u003e\n\u003cp\u003eThe 94.9% average over 400-500 nm gives each measured wavelength equal weight; an LED may concentrate its output in a narrow peak within that interval. Look up your actual emission wavelengths on the CTB-200 curve, or evaluate a sample with your source and detector.\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 Temperature Blue (Cooling) Filter \/ 3\/4 CTB","offer_id":48516671766783,"sku":"CTB-200","price":0.0,"currency_code":"TWD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0818\/8651\/1359\/files\/ctb-200-spectrum.jpg?v=1778712961"},{"product_id":"ctb-004","title":"CTB-004 Cooling Color-Correction Filter","description":"\u003cnav aria-label=\"Product family\"\u003e\u003cp\u003e\u003ca href=\"\/collections\/all-products\"\u003eAll optics\u003c\/a\u003e \/ \u003ca href=\"\/collections\/color-temperature-blue-cooling-filter\"\u003eColor Temperature Blue Filters\u003c\/a\u003e\u003c\/p\u003e\u003c\/nav\u003e\u003csection class=\"ko-reviewed\"\u003e\u003ch2 class=\"ko-catalog-description-title\"\u003eCTB-004 Reference Optical Response\u003c\/h2\u003e\n\u003cp\u003eCTB-004 is a cooling color-correction filter referenced to the customer sample book. Evaluate the correction with the spectrum of your actual light source.\u003c\/p\u003e\n\u003ch3\u003eOptical performance\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMeasured wavelength range:\u003c\/strong\u003e 380-780 nm. Performance outside this interval is not established.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePeak transmission:\u003c\/strong\u003e Approximately 93.671% at 439 nm. This is a sample measurement, not an order tolerance.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSelection note:\u003c\/strong\u003e The customer sample-book curve is the reference for this listing. Confirm that your sample-book edition and order refer to the same design.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"ko-note\"\u003eThese values describe a measured measured sample. Custom versions and production orders have their own agreed specifications.\u003c\/p\u003e\n\u003ch3\u003eChoosing this filter\u003c\/h3\u003e\n\u003cp\u003eCompare the full source spectrum and desired transmitted region. Tell us the working angle, dimensions and required rejection.\u003c\/p\u003e\n\u003ch3\u003eCustom options\u003c\/h3\u003e\n\u003cp\u003eDiscuss the wavelength response, substrate, dimensions and operating conditions with KUPO.\u003c\/p\u003e\u003c\/section\u003e\u003ch3\u003eTransmission spectrum\u003c\/h3\u003e\u003ciframe src=\"https:\/\/charts.kupooptics.com\/CTB-004.html\" title=\"CTB-004 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 CTB-004\u003c\/h2\u003e\n\u003ch3\u003eIs the curve here the customer-facing CTB-004 reference?\u003c\/h3\u003e\n\u003cp\u003eThis listing follows the customer sample-book reference over 380-780 nm. Its measured peak is 93.671% at 439 nm. If your factory sheet looks different, send us the edition or label rather than assuming the curves describe the same version.\u003c\/p\u003e\n\u003ch3\u003eCan CTB-004 guarantee a particular color temperature?\u003c\/h3\u003e\n\u003cp\u003eThe sample peak of 93.671% at 439 nm is only one point on the curve. Compare the complete sample-book spectrum with your actual lamp: the balance of blue, green and red light determines the correction. Share your source spectrum and target color balance with us.\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 Temperature Blue (Cooling) Filter \/ 3\/4 CTB","offer_id":48516671799551,"sku":"CTB-004","price":0.0,"currency_code":"TWD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0818\/8651\/1359\/files\/ctb-004-spectrum.jpg?v=1778712963"},{"product_id":"ctb-003","title":"CTB-003 Cooling Color-Correction Filter","description":"\u003cnav aria-label=\"Product family\"\u003e\u003cp\u003e\u003ca href=\"\/collections\/all-products\"\u003eAll optics\u003c\/a\u003e \/ \u003ca href=\"\/collections\/color-temperature-blue-cooling-filter\"\u003eColor Temperature Blue Filters\u003c\/a\u003e\u003c\/p\u003e\u003c\/nav\u003e\u003csection class=\"ko-reviewed\"\u003e\u003ch2 class=\"ko-catalog-description-title\"\u003eCTB-003 Reference Optical Response\u003c\/h2\u003e\n\u003cp\u003eCTB-003 is a cooling color-correction filter referenced to the customer sample book. Evaluate the correction with the spectrum of your actual light source.\u003c\/p\u003e\n\u003ch3\u003eOptical performance\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMeasured wavelength range:\u003c\/strong\u003e 380-780 nm. Performance outside this interval is not established.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePeak transmission:\u003c\/strong\u003e Approximately 87.689% at 436 nm. This is a sample measurement, not an order tolerance.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSelection note:\u003c\/strong\u003e The customer sample-book curve is the reference for this listing. Confirm that your sample-book edition and order refer to the same design.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"ko-note\"\u003eThese values describe a measured measured sample. Custom versions and production orders have their own agreed specifications.\u003c\/p\u003e\n\u003ch3\u003eChoosing this filter\u003c\/h3\u003e\n\u003cp\u003eCompare the full source spectrum and desired transmitted region. Tell us the working angle, dimensions and required rejection.\u003c\/p\u003e\n\u003ch3\u003eCustom options\u003c\/h3\u003e\n\u003cp\u003eDiscuss the wavelength response, substrate, dimensions and operating conditions with KUPO.\u003c\/p\u003e\u003c\/section\u003e\u003ch3\u003eTransmission spectrum\u003c\/h3\u003e\u003ciframe src=\"https:\/\/charts.kupooptics.com\/CTB-003.html\" title=\"CTB-003 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 CTB-003\u003c\/h2\u003e\n\u003ch3\u003eHow do I match my CTB-003 sample to the spectrum here?\u003c\/h3\u003e\n\u003cp\u003eThis listing follows the customer sample-book reference over 380-780 nm. Its measured peak is 87.689% at 436 nm. If your factory sheet looks different, send us the edition or label rather than assuming the curves describe the same version.\u003c\/p\u003e\n\u003ch3\u003eWhat should I compare before using CTB-003 on an LED source?\u003c\/h3\u003e\n\u003cp\u003eThe sample peak of 87.689% at 436 nm is only one point on the curve. Compare the complete sample-book spectrum with your actual lamp: the balance of blue, green and red light determines the correction. Share your source spectrum and target color balance with us.\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 Temperature Blue (Cooling) Filter \/ 1\/4 CTB","offer_id":48516671832319,"sku":"CTB-003","price":0.0,"currency_code":"TWD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0818\/8651\/1359\/files\/ctb-003-spectrum.jpg?v=1778712964"},{"product_id":"ctb-002","title":"CTB-002 Cooling Color-Correction Filter","description":"\u003cnav aria-label=\"Product family\"\u003e\u003cp\u003e\u003ca href=\"\/collections\/all-products\"\u003eAll optics\u003c\/a\u003e \/ \u003ca href=\"\/collections\/color-temperature-blue-cooling-filter\"\u003eColor Temperature Blue Filters\u003c\/a\u003e\u003c\/p\u003e\u003c\/nav\u003e\u003csection class=\"ko-reviewed\"\u003e\u003ch2 class=\"ko-catalog-description-title\"\u003eCTB-002 Reference Optical Response\u003c\/h2\u003e\n\u003cp\u003eCTB-002 is a cooling color-correction filter referenced to the customer sample book. Evaluate the correction with the spectrum of your actual light source.\u003c\/p\u003e\n\u003ch3\u003eOptical performance\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMeasured wavelength range:\u003c\/strong\u003e 380-780 nm. Performance outside this interval is not established.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePeak transmission:\u003c\/strong\u003e Approximately 86.040% at 435 nm. This is a sample measurement, not an order tolerance.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSelection note:\u003c\/strong\u003e The customer sample-book curve is the reference for this listing. Confirm that your sample-book edition and order refer to the same design.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"ko-note\"\u003eThese values describe a measured measured sample. Custom versions and production orders have their own agreed specifications.\u003c\/p\u003e\n\u003ch3\u003eChoosing this filter\u003c\/h3\u003e\n\u003cp\u003eCompare the full source spectrum and desired transmitted region. Tell us the working angle, dimensions and required rejection.\u003c\/p\u003e\n\u003ch3\u003eCustom options\u003c\/h3\u003e\n\u003cp\u003eDiscuss the wavelength response, substrate, dimensions and operating conditions with KUPO.\u003c\/p\u003e\u003c\/section\u003e\u003ch3\u003eTransmission spectrum\u003c\/h3\u003e\u003ciframe src=\"https:\/\/charts.kupooptics.com\/CTB-002.html\" title=\"CTB-002 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 CTB-002\u003c\/h2\u003e\n\u003ch3\u003eWhy does this CTB-002 listing use the sample-book curve?\u003c\/h3\u003e\n\u003cp\u003eThis listing follows the customer sample-book reference over 380-780 nm. Its measured peak is 86.040% at 435 nm. If your factory sheet looks different, send us the edition or label rather than assuming the curves describe the same version.\u003c\/p\u003e\n\u003ch3\u003eCan I choose CTB-002 from its peak transmission alone?\u003c\/h3\u003e\n\u003cp\u003eThe sample peak of 86.040% at 435 nm is only one point on the curve. Compare the complete sample-book spectrum with your actual lamp: the balance of blue, green and red light determines the correction. Share your source spectrum and target color balance with us.\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 Temperature Blue (Cooling) Filter \/ 3\/4 CTB","offer_id":48516672028927,"sku":"CTB-002","price":0.0,"currency_code":"TWD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0818\/8651\/1359\/files\/ctb-002-spectrum.jpg?v=1778712965"},{"product_id":"ctb-001","title":"CTB-001 Cooling Color-Correction Filter","description":"\u003cnav aria-label=\"Product family\"\u003e\u003cp\u003e\u003ca href=\"\/collections\/all-products\"\u003eAll optics\u003c\/a\u003e \/ \u003ca href=\"\/collections\/color-temperature-blue-cooling-filter\"\u003eColor Temperature Blue Filters\u003c\/a\u003e\u003c\/p\u003e\u003c\/nav\u003e\u003csection class=\"ko-reviewed\"\u003e\u003ch2 class=\"ko-catalog-description-title\"\u003eCTB-001 Reference Optical Response\u003c\/h2\u003e\n\u003cp\u003eCTB-001 is a cooling color-correction filter referenced to the customer sample book. Evaluate the correction with the spectrum of your actual light source.\u003c\/p\u003e\n\u003ch3\u003eOptical performance\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMeasured wavelength range:\u003c\/strong\u003e 380-780 nm. Performance outside this interval is not established.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePeak transmission:\u003c\/strong\u003e Approximately 91.869% at 401 nm. This is a sample measurement, not an order tolerance.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSelection note:\u003c\/strong\u003e The customer sample-book curve is the reference for this listing. Confirm that your sample-book edition and order refer to the same design.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"ko-note\"\u003eThese values describe a measured measured sample. Custom versions and production orders have their own agreed specifications.\u003c\/p\u003e\n\u003ch3\u003eChoosing this filter\u003c\/h3\u003e\n\u003cp\u003eCompare the full source spectrum and desired transmitted region. Tell us the working angle, dimensions and required rejection.\u003c\/p\u003e\n\u003ch3\u003eCustom options\u003c\/h3\u003e\n\u003cp\u003eDiscuss the wavelength response, substrate, dimensions and operating conditions with KUPO.\u003c\/p\u003e\u003c\/section\u003e\u003ch3\u003eTransmission spectrum\u003c\/h3\u003e\u003ciframe src=\"https:\/\/charts.kupooptics.com\/CTB-001.html\" title=\"CTB-001 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 CTB-001\u003c\/h2\u003e\n\u003ch3\u003eWhich spectrum represents CTB-001 in the customer sample book?\u003c\/h3\u003e\n\u003cp\u003eThis listing follows the customer sample-book reference over 380-780 nm. Its measured peak is 91.869% at 401 nm. If your factory sheet looks different, send us the edition or label rather than assuming the curves describe the same version.\u003c\/p\u003e\n\u003ch3\u003eWill CTB-001 give the same cooling effect on every lamp?\u003c\/h3\u003e\n\u003cp\u003eThe sample peak of 91.869% at 401 nm is only one point on the curve. Compare the complete sample-book spectrum with your actual lamp: the balance of blue, green and red light determines the correction. Share your source spectrum and target color balance with us.\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 Temperature Blue (Cooling) Filter \/ Full CTB","offer_id":48516672225535,"sku":"CTB-001","price":0.0,"currency_code":"TWD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0818\/8651\/1359\/files\/ctb-001-spectrum.jpg?v=1778712967"}],"url":"https:\/\/kupooptics.com\/collections\/color-temperature-blue-cooling-filter.oembed","provider":"KUPO Optics","version":"1.0","type":"link"}