The main purpose for shooting on a greenscreen is to be able to remove the color and have a transparent background. Make sure when lighting your background, the lighting is as even as possible. 

Tutorial

Here are the steps in After Effects that I follow when pulling a greenscreen key:

Add color key

Grab green by person

Adjust tolerance

Add another color key

Grab green (with eye dropper)  near the edge (that is not being keyed)

Adjust tolerance

Add simple choker

Expand the matte to like -100…

Create new magenta solid

Add “Keylight”

Select a green color

Change view to “combined matte”

Under screen matte

Raise the “clip black” just a little

Lower the “clip white” just a little

Make sure not to lose the fine detail

Use screen shrink/grow to bring it down to like -1.5 or so…just to get rid of any little green spill 

Change screen softness to 2 or so…

Change soft color to hard color (personal taste)

Conclusion

There are many programs that will allow you to pull out a key based on chroma (color), but After Effects is an industry-standard tool. Hopefully, you find this tutorial helpful.

Happy keying!

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