Some Basic Tips
Stay away from the background!
When you keep a minimum of 10’ between your subject and the green background, it minimizes green ‘spill’ from the backdrop.
If you don't need a full body (head-to-toe) shot, don't bring a green screen sweep any further forward than you need for the shot.
Less green spill = a cleaner matte
Cover unseen green areas
Seems like a no-brainer, but if it’s not needed for the matte, it doesn’t need to be there bouncing green spill around the room! To be doubly safe, cover those unseen green areas with light pink sheets (the pink minimizes green.)
Add edge and back lights
This is particularly true when shooting full length shots, since light coming back at the subject from the green screen must be counteracted, plus edge lights will probably help make your subject look like they are ‘lit in the real world’
In fact, adding a light minus-green (magenta) gel, such as a 1/8 or 1/4, will help counteract any green that your edge light is working to overcome!
Avoid the use of fluorescent bulbs to light your subject.
Virtually all fluorescent tubes emit a ‘spike’ in the green area. If you don’t believe me, go look at the spectral analysis curves at the Kino-Flo website. Using fluorescents is, however, an excellent way to light your green background!
Be careful of your wardrobe!
A surprising number of materials are reflective enough to ruin an otherwise perfect matte. Particularly watch out for items like shiny black boots (sure to pick up green reflections.)
Also be careful of ‘blue’ jeans. In many ‘pre-washed’ styles, the blue of the jeans has faded to reveal a yellow-green tinge! In general, watch out for not only greens, but yellows as well, since many yellow shades contain quite a bit of green.
Pull your matte from the highest resolution, earliest generation original you have.
Seems like another no-brainer, but remember that every time you transcode or go another generation, or even worse move to a compressed editing format, you are losing resolution and color information that may be the difference between a marginal and a great matte.
Use a robust color space.
You've probably heard the numbers 4:2:2 and 4:2:0 used to describe the tech specs of recording formats. Without going into a full technical explanation, the critical thing to remember is that 4:2:0 only has half the color resolution of 4:2:2, so shooting in 4:2:2 should give you a better matte. Of course 4:4:4 is even better, but that will most likely involve an external recorder, as well as a lot more data.
Working With Green Screen
Green Screen is a method used for creating mattes. A foreground person or object is filmed or videotaped with a green background. Through a matting process, the green essentially becomes ‘transparent’ and allows a background to be seen instead.