View Full Version : Filters on LED light


Marcus Martell
November 12th, 2011, 10:20 AM
Guys i wanted to know what's the use of the different colors of filters on the light panel like the ones on this video
REVIEW: ePhoto LED Panels on Vimeo

Thx guys, i'm thinking to buy this model

Marcus Martell
November 13th, 2011, 07:10 AM
I know that is like put gels on the old IANIRO lamps that i use but i used just the orange one to bring the temperature to 3200 kelvin.

But what's the story behind the violet and the other ones?
thx

Andrew Dean
November 19th, 2011, 12:17 PM
LEDs are not a complete or continuous spectrum. They tend to have a "spike" in the green part of the light they emit. It can be so extreme as to look green or as subtle as looking like white light but making skin tones a bit sickly.

The violet color gel is a "Minus green" gel. It is opposite from green on the color wheel and therefore lets all light *except* green come through, which acts to selectively filter out the spike (but also reduce the total output like a ND filter.) In theory the fixtures should have the minusgreen built in, however, a properly white balanced camera can ignore the spike without reducing the light value. So, in cases where you are ONLY using the LED lights, you'll have more light to work with by removing the minusgreen gel. If you are mixing the LED with sunlight spilling in a window or with another daylight source, then white balance cant remove the spike without messing up the color of the other sources. So, the solution for versatility is to offer the lights with a removeable minusgreen filter.

Led panels are made up of many small led "bulbs" (acutally a complete fixture in their own right since each has a light source and a lens). This means that each light casts its own focused shadow. In some cases this can show up and have "pixelated" shadows. To minimize this, you can put a frost filter on the lights and it essentially becomes a single, large (larger than an individual led at least) source of light that is a little diffused. Additionally you may just want to diffuse the light a little so the shadows aren't as hard, and the same frost filter is good for that.

Hope that makes sense.

Cheers!
-a

Chuck Fishbein
December 6th, 2011, 11:45 AM
Adding to Andrew's comments...

The cheaper the price, the more inaccurate your color will be when it comes to LEDs. A good part of what you are paying for with Lite Panels and a few other high cost brands is the high CRI value which means how close the light output is to true 5600K or 3200K. I have used both the expensive and cheap versions of the LED panels and you may not want to go cheap here. I mean the whole point of using daylight LEDs is to be able to match real daylight. Right?

Some of this can be fixed with careful use of gels, but if the missing color is missing from your LED's spectrum, filtering won't help and as Andrew mentioned, you will cut back on your light.

One great thing about LEDs is due to the fact that the lights give off almost no heat, you can keep it very close to your subject and use diffusion filter or even tracing paper to soften the light for very pleasing results.

Remember, even a large, soft light, becomes a contrasty, much harder source if it is moved back to far from the subject.

Michael Morlan
December 16th, 2011, 04:22 PM
Marcus,

Take a look at my review of the ePhoto 1x1 panel to know what you'll be dealing with. I compare it with the Lightpanels 1x1 Superspot and a Lowel 250w ProLight:

http://www.dvinfo.net/forum/photon-management/503637-couple-1x1-led-panels-tested.html

Best,

Michael