Emitter color correction

In the motion picture business it is common to adjust color temperature of lighting to match films or looks. For example when you go to shoot in a room full of florescent lights they gel the light with I think a light orange gel so on film the shot doesn't look green. It is complicated. the gaffer and director of photography do make these decisions. not me. So I don't really know much about it. Bur I do know this. and I have mentioned this before. there are these little books full of literally 200 sample peices of these gels available free from companies like LEE filters.
These can be used to adjust the color temperature or tint of your led's. You can easily make a green tinted led look near perfect with a gel and light loss is there but minimal.
Do any of you guys have any good ideas in cutting perfect little circles the same size as a flashlight window or lens? I need help with this and I am stuck.
Thanks
Yaesumofo

Sharpen the end of a piece of metal pipe of the appropriate size, then use it with a hammer to punch out the circle.

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yaesumofo said:
For example when you go to shoot in a room full of florescent lights they gel the light with I think a light orange gel so on film the shot doesn't look green.


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You only need to do that with the old school T-12 cool white or warm white halophosphor lamps which are in use less and less these days. The color rendering of even the cheap T-8 triphosphor lamps is quite good. The ones with the SPX phosphors are even better, and the full-spectrum 5000K lamps offered by quite a few manufacturers come pretty close to sunlight. It seems easier to me to change a few tubes than to mess around with gels and filters, or maybe those in the industry simply aren't aware of how good fluorescent lighting has gotten. And there is no 120 Hz flicker any more either with the electronic ballasts.

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Do any of you guys have any good ideas in cutting perfect little circles the same size as a flashlight window or lens? I need help with this and I am stuck.


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If it's a thin film then using the flashlight lens as a guide, use an Xacto knife to cut the film. Just lay the lens on top of the film, and trace the knife around the circumference. The result should be a nice, neat cut.

If the material is thicker, again use the lens as a guide to mark a cutting circle on the material, and then cut it using a jigsaw with a small blade.

See post "De-Greening Luxeons #311016 - Tue Aug 12 2003"

"De-Greening Luxeons"