CTO-032 Warming color-correction filter

CTO-032 is a warming color-correction filter that reduces blue-to-green light relative to longer visible wavelengths. Use it to adjust a broadband source’s color balance; the final effect depends on the lamp spectrum.

Measured wavelength range: 380-800 nm
400-500 nm: 37.6% average transmission
500-600 nm: 21.9% average transmission
600-700 nm: 66.7% 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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Warming color-correction filter (CTO-032)

CTO-032 is a warming color-correction filter. It reduces blue-to-green light relative to longer visible wavelengths. This can give a suitable broadband light source a warmer balance. Average transmission in the sample is 37.6% over 400-500 nm, 21.9% over 500-600 nm, 66.7% 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 37.6% average transmission; the range is 9.7-66.3% in the measured curve.
500-600 nm: Approximately 21.9% average transmission; the range is 17.7-29.6% in the measured curve.
600-700 nm: Approximately 66.7% average transmission; the range is 29.6-90.2% in the measured curve.
Measured edge at 50% transmission: Approximately 632.4 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

Stage and architectural lighting: Try it when you need a warmer balance from a broadband white light source. Check the color and brightness with your actual light source before choosing a filter.
Film and photographic lighting: Consider it for warming a daylight or cool-white fixture toward another light in the scene. Measure the color match with the actual fixtures and camera.
Fixture development: Use the measured color-shaping profile to compare available coatings. Confirm the required color temperature, tint, throughput and operating conditions on the assembled fixture.

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 CTO-032

What do the measured values tell me about CTO-032 on white light?

The sample averages are 37.6% over 400-500 nm; 21.9% over 500-600 nm; 66.7% over 600-700 nm. Compare those bands rather than treating the filter as a uniform dimmer: the relative transmission is what changes the light balance.

What does the 50% crossing near 632.4 nm mean for CTO-032?

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 CTO-032, 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.