Lighting for Chroma at DVinfo.net

Jon Vincent · January 14th, 2010, 10:22 PM

Hey everyone - Already have most of the basics down on this, but looking for some tips on lighting the rear green screen on our studio evenly.

We're using a 2x4 bulb coollight config to hit a back wall that is about 10 ft wide. Since the lights are coming from above the wall they are a bit hotter at the top and then, naturally, the light falls slowly off as it goes down the wall. It's not a huge problem to key off it, but would be nice if the green was more even.

So, a couple ways I could do this. I could toss a couple smaller 2 bulb coollights at the bottom, which would even it out, but I am worried about creating more bounce that I'll have to deal with. Another idea would be to just put a couple reflectors back there and see how much of it I could even out. Since we're not doing full body shots they would be behind the talent and could not be seen.

Anybody used bounce cards to even out lighting on their green (or blue) screen?

Paul E. Coleman · January 17th, 2010, 07:31 PM

If you have access to a Waveform / Vectorscope, even within your editing software use it to view the screen alone with no obstructions. With the Waveform you want a nice straight line from side to side, you'll easily notice any bright spot by an un-level line. With the Vectorscope you can view the color intensity levels. Using them has made lighting a screen easy with almost any lighting type.

Gregory Gesch · January 19th, 2010, 04:59 PM

Hi Jon. If you don't have access to a wavefore/vectroscope you can also use your zebra pattern to check for darker spots.

Jon Vincent · January 29th, 2010, 07:10 PM

Thanks guys. It's not a problem seeing the light falloff. Used the zebra patterns to check that. Not as nice as the scopes, but gives me a good idea. Could have used the scopes in the PC too I guess, great idea.

Anyway, the question was really more around how to even the lighting out.

I did end up going with some bounce cards that I mounted low. They seem to be throwing back enough light to give me an almost perfect smooth zebra pattern now. Went with the cards instead of lights to keep down the price, heat, and power usage.

January 14th, 2010, 10:22 PM	#1
Jon Vincent Regular Crew Join Date: Dec 2009 Location: Emeryville, CA Posts: 34	Lighting for Chroma Hey everyone - Already have most of the basics down on this, but looking for some tips on lighting the rear green screen on our studio evenly. We're using a 2x4 bulb coollight config to hit a back wall that is about 10 ft wide. Since the lights are coming from above the wall they are a bit hotter at the top and then, naturally, the light falls slowly off as it goes down the wall. It's not a huge problem to key off it, but would be nice if the green was more even. So, a couple ways I could do this. I could toss a couple smaller 2 bulb coollights at the bottom, which would even it out, but I am worried about creating more bounce that I'll have to deal with. Another idea would be to just put a couple reflectors back there and see how much of it I could even out. Since we're not doing full body shots they would be behind the talent and could not be seen. Anybody used bounce cards to even out lighting on their green (or blue) screen?

January 17th, 2010, 07:31 PM	#2
Paul E. Coleman Regular Crew Join Date: Sep 2007 Location: 42º 12' N, 72º 32' W Posts: 88	Waveform / Vectorscope are very helpful If you have access to a Waveform / Vectorscope, even within your editing software use it to view the screen alone with no obstructions. With the Waveform you want a nice straight line from side to side, you'll easily notice any bright spot by an un-level line. With the Vectorscope you can view the color intensity levels. Using them has made lighting a screen easy with almost any lighting type.

January 19th, 2010, 04:59 PM	#3
Gregory Gesch Regular Crew Join Date: Jun 2009 Location: Brisbane Australia Posts: 114	Hi Jon. If you don't have access to a wavefore/vectroscope you can also use your zebra pattern to check for darker spots.

January 29th, 2010, 07:10 PM	#4
Jon Vincent Regular Crew Join Date: Dec 2009 Location: Emeryville, CA Posts: 34	Thanks guys. It's not a problem seeing the light falloff. Used the zebra patterns to check that. Not as nice as the scopes, but gives me a good idea. Could have used the scopes in the PC too I guess, great idea. Anyway, the question was really more around how to even the lighting out. I did end up going with some bounce cards that I mounted low. They seem to be throwing back enough light to give me an almost perfect smooth zebra pattern now. Went with the cards instead of lights to keep down the price, heat, and power usage.