CRI-8 Spectral-shaping filter for color correction

CRI-8 is a spectral-shaping filter for color correction. It reshapes the source spectrum by attenuating selected visible wavelengths rather than adding missing colors.

Measured wavelength range: 380-800 nm
400-500 nm: 55.6% average transmission
500-600 nm: 27.5% average transmission
600-700 nm: 62.1% average transmission
Custom options: Wavelength response, dimensions and operating conditions

Values shown are sample measurements. Final specifications are agreed for your order.

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Spectral-shaping filter for color correction (CRI-8)

CRI-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.

Optical performance

Measured wavelength range: 380-800 nm. Performance outside this measured interval is not established by this curve.
400-500 nm: Approximately 55.6% average transmission; the range is 13.4-92.8% in the measured curve.
500-600 nm: Approximately 27.5% average transmission; the range is 20.8-67.6% in the measured curve.
600-700 nm: Approximately 62.1% average transmission; the range is 25.7-94% in the measured curve.
Measured edge at 50% transmission: Approximately 472.3 nm. Interpolated absolute-transmission crossing, checked against the factory summary.
Customization: We can customize stock and sample-book designs. Tell us the wavelength response, size and operating conditions you need.

These 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.

Applications to consider

LED and discharge-lamp development: Check whether reducing selected peaks improves the balance of your light source. Compare color rendering and luminous output before and after filtering.
Studio and display lighting: 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.
Color-correction trials: 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.

Choosing this filter

Evaluate the filter together with the intended light source. Color temperature, tint, color rendering and luminous output depend on that combination.
Tell us the size, shape and working angle you need, along with the temperature conditions inside the fixture.

Custom options

Start 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.

Transmission spectrum

Questions about CRI-8

What does the spectrum establish about CRI-8 and color rendering?

The 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.

What does the 50% crossing near 472.3 nm mean for CRI-8?

It 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.

Discuss this filter with KUPO - include the product reference, source wavelength, working angle and required dimensions.