Questions about shooting Chromakey Green

[Sonny]

A company wants to hire me to shoot cheerleaders on a Chromakey Green background. The images will be used for a wall cut out like Fathead.

What are the dos and don'ts for shooting Chromakey Green?

[Some Idiot]

from my limited experience with Chromakey. I can tell you that it is really important to have even lighting across the entire background, One constant tone of green. Several tones of green turns into a photoshop nightmare.

Im sure more advise is on the way, congrats on the job

[ldelacruz]

Originally Posted by Some Idiot

from my limited experience with Chromakey. I can tell you that it is really important to have even lighting across the entire background, One constant tone of green. Several tones of green turns into a photoshop nightmare.

Im sure more advise is on the way, congrats on the job

It has been a while for me to but I agree with Rob here. Light it evenly across and at the same fstop as your key light. Also be careful to not have the color spill onto your subject either by being to close to the the background or the color bouncing off the walls in a small room or area. This is one style where you want to get it as close as possible in camera. Getting it right in camera will save you a ton in post!

[Flores]

+1 on lighting. From my limited experience with the technique, having the color 'bounce' onto the subject totally ruins the effect.

[Sonny]

This is great information. I have a few more questions regarding your answers.

Even Background Lighting:

1. How do I evenly light the background with only two off camera 580ex speedlights and two shoot through umbrellas? I can also substitute one of the umbrellas for a Photoflex Medium (24"x32") Softbox w/ Nylon Grid
2. At the same time, how do I properly light the subject with the same setup?
3. Should I have each light on either side of the subject at 30-45 degree angles from the camera?

Color Spill:
I was afraid of this. So far what I know is the client will provide the Chromakey Green Background, but it will be small. There will not be much material to extend far enough away from the background.

Post Processing:
The client requested that I only do the shooting. Somebody else will be doing the extractions of the cheerleaders.

[rab3rd]

Sonny, depending on your budget. Cowboy lighting has a pretty big chromagreen backdrop for about 50-60 bucks. I think its a 10x20 IIRC. I bought one this size in gray and black and it is freakin massive...

[Redneck]

Seriously, you need to move your model as far away from the background as possible because the colored light will spill. It is a real pain to get the light green (or blue) shine out of the hair in pp. I actually don't think you can pull this off at a decent quality with just two lights. I would try positioning the lights at 45 degrees in front of the motif but would rather have at least 4 if not 5 lights (2 for background, 2 or 3 for the motif).

[danchez]

lighting a background and a model with just 2 speedlights... now that's a challenge.

[daveb]

I do a great deal of chroma key ...
Here are a couple of things ...

Watch your colors ... if you have blonds I would not use a green key ... use blue blond hair will pickup any spill additionally if they have green in their uniforms go for a blue key.

2) As others have said light your background as evenly as possible and move your subjects as far away from the background as you can to avoid spill.

3) watch your floor again for signs of spill ( I have been known to put down white paper so I dont have green spill on feet.

Spill is going to be your enemy watch for it very closely

[Sonny]

Big ole THANKS to all you for all the helpful information.

[texpic]

I've shot a lot of green/blue backgrounds. Spill is the major issue. I worry less about getting even lighting on the background than spill. I use MaskPro to extract, so the critical area is the transition between the subject and the background. The remainer of the background can be painted out in seconds.

If this is a full body shot make sure the lighting on the subject is right and try to get the subject as far from the green as possible to avoid spill.