I am trying to use the keylight function to make a nice green screen effect. So I use the pen tool to cut out just what I want and it works fine, but a few frames along in the video, my camera moves a bit and picks up some extra video to the right of the subject and it moves into the green screen effect area.
I tried to copy the layer and cut that part out so you would just see the background, but I am doing something wrong. How to fix that?
using after effects cs5
Enable keyframes on the mask path then edit the points of the masks.
Also, try looking up the term "garbage matte." It's relatively simple concept that can be executed using many different tools and levels of sophistication.
Here's my workflow for standard greenscreen work, stuff that isn't too action-oriented, similar to conventional weather presentations:
1. Capture the footage in Final Cut Pro.
2. Seldct the takes.
3. IMport the best takes into After Effects.
4. Apply masking to the video to remove as much unnecessary stuff as possible using as few vertices in the mask as possible.
5. Apply Keylight.
6. Export to ProRes4444.
7. Import back into FCP.
Additional work might be required for wire or rig removal, rotoscoping for movement in front of or behind foreground objects, masking replacement layers to manage stupid costume errors like a green tie, light wrap, spill removal, reflection cancelation, shadow manipulation.