This thread is interesting. A friend replaced the head of a dancer with drawing. I don“t know if the dancer had multiple trackpoints on his head, but I he had just a colored green jockey or something.
http://www.smog.tv/ It`s the one called "Mono" in the bottom-right.
"And definitely don't underexpose the subject. You want the whites to be significantly brighter than the green background - which will help separate them when you're keying."
Why should it be more dificult to separate a darker subject from a green screen?
Is it better to underexposure the subject in post? Why?
cheers
Seb