Luminous Landscape Forum
Equipment & Techniques => Medium Format / Film / Digital Backs – and Large Sensor Photography => Topic started by: JoeKitchen on January 05, 2012, 04:04:37 pm
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What gel would you use to get a tungsten fresnel to match a LED light. I was told by the manufacturer that the LED light temp is 30K.
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Maybe easier the other way around? Try some CTO over the LED or some CTB over the Tungsten.
Maybe you'll need to filter both to get both sort-of close...
Fast and easy way to check maybe to shoot a digital gray card under the LED and analyze the color temp and tint in ACR to get baseline data, then work your way to balance from there.
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Gelling the LED would not work. I am documenting the installation of LED flood lights on a local library; they are about 4 feet long and there are 6 of them.
I want to use a tungsten as full and would prefer gelling the tungsten to get a close match. Preferably off enough so if I correct for the gelled light, the LED light will be little discolored but not too much.
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What gel would you use to get a tungsten fresnel to match a LED light. I was told by the manufacturer that the LED light temp is 30K.
Joe, Do you mean that the color temp of the LED is 3000K, if so, it's theoretically 200 degrees warmer than the tungsten light (at 3200). Bulbs can exhibit some variability but try an 1/8CTO or 1/16CTO. Another approach would be to shoot a grey card with both light sources on and balance off of it, if the results are a little warm or cooler, desaturate the color you don't like. Jim
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If you need 100% accuracy you should rent a color meter.
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Joe,
Don't know the area your trying to cover, but rather than try to filter tungsten to LED's why not just rent 1x1 LED Lightpanels. They make a version with a variable color temp, which is probably just some kind of faux coloration, though we have some and they work well. Just turn the dial until it matches, or you like the look.
Keep in mind the LED's are kind of strange to light with. When direct they produce a lot of light, but bounced, or diffused they drop off quickly, so if you need three 575 HMI's you'll probably need 6 light panels.
IMO
BC
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Two sandwiched full CTB will give you 12000-14000k.
Maybe you can "trial and error" with 3-4 even 5 FULL CTB.
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LED can be really tricky and often renders color very differently in capture than it does to the eye.
Can you get one of their units into studio? In a dark space I would light a Grey Card with their source and then just White Balance the card in C1 Pro (or whatever) to get an idea of the product's color. Then do the same with your tungsten and add CTB or CTO in 1/8 or 1/4 increments until you get the two aligned.
This will give you the most accurate match.
CB
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Thanks all for the info. I will probably go with Chris's suggestion.
Jim, 30K is what the guy told and he was only a marketing person who did not know a lot about light. I am thinking it is 3000K; 30K sound way too low.