Dave, thanks for the reply…read this to understand where my question came from:
“Maybe the biggest innovation is the elastic background. Back in the medieval era (a couple years ago), the colored screen behind your subject had to fill the entire frame, so that the replacement background composited onto it would do the same. Now, most decent editing software packages will let you take an incomplete colored background and digitally stretch it to all four corners. All you have to do is ensure that your subject, at least, is surrounded by the key color. This means you can get great results even with small screens and tight shooting areas.”
I recently did a shoot & accidentally had the background not filling the entire frame. I thought the above provided a solution to this problem.
You may be talking about a masking technique that solves the same issue that I’m not aware of. Any further help would be appreciated.
Thanks!