When you plan on using the chroma key feature in Final Cut Pro do you have to incorporate enough green screen into the shot to simulate the size of the back ground you plan on using or can you simply frame the person that will be placed in front of the back ground. Does the answer change if part of the green screen background is going to be an inset frame for graphics or video to pop up co-ordinated with the subject's dialogue?
As long as you have a clear boundary around the subject of at least an inch to a couple of inches, that's all you need for ANY size of final comp. That's sort of the point of the whole thing. You don't need a huge green wall, just a minimum amount of clear green around the subject, then you mask off the rest using the crop tools or what we call "garbage masks" or mattes.