HMG-7 Minus-green correction filter

HMG-7 is a minus-green correction filter. It attenuates part of the green-to-yellow region relative to surrounding wavelengths.

Measured wavelength range: 380-800 nm
400-500 nm: 80.5% average transmission
500-600 nm: 79.1% average transmission
600-700 nm: 91.9% 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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Minus-green correction filter (HMG-7)

HMG-7 is a minus-green correction filter. It attenuates part of the green-to-yellow region relative to surrounding wavelengths. This can help reduce a green cast in lighting. Average transmission in the sample is 80.5% over 400-500 nm, 79.1% over 500-600 nm, 91.9% 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 80.5% average transmission; the range is 75.2-88.5% in the measured curve.
500-600 nm: Approximately 79.1% average transmission; the range is 69-89.1% in the measured curve.
600-700 nm: Approximately 91.9% average transmission; the range is 73.5-96.1% in the measured curve.
Measured edge at 85% transmission: Approximately 528.6 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

Mixed-source film and studio lighting: Try it when matching fixtures that have different amounts of green in their light. Choose strength by measuring the resulting tint.
Photography and camera matching: Consider spectral tint adjustment at the light source before camera profiling. Confirm the effect on the colors important to the shoot.
Luminaire color tuning: Compare minus-green filters with your actual light source, and check how much light each one removes.

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 HMG-7

How can I judge the strength of HMG-7?

Compare the sample averages: 80.5% over 400-500 nm; 79.1% over 500-600 nm; 91.9% over 600-700 nm. Those bands help you judge both the correction and the light you retain, but a narrow green emission line should be checked at its actual wavelength on the curve.

What does the 85% crossing near 528.6 nm mean for HMG-7?

It identifies where this measured curve crosses 85% 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 HMG-7, 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.