If I want to make a video (I'm not yet sure of what's a clip and what's a sequence) where there are two people over a static background and time moves faster for one than the other, how would I do that?
Intuitively, I'd film both... clips? from the same viewpoint and then I'd have to combine them in such a way that the parts that are equal, or constant, are combined/shared, while the parts of each frame that are different, or changing, are taken from only one of the videos.
One way of doing that would be to cut one of the persons from one of the clips and superpose that on the other but I don't know how difficult that is.
As an additional question, how much harder would it be to to that same video with an equal but changing background? (I'd have to find the mechanical means of filming the same movement twice but that's a more mundane problem).
[edit: I suppose my questions are, more succinctly:
- "is after effects the correct tool?"
- "do I just need to learn to use layers in video, which work just as layers in Photoshop but somehow are able to follow the movement of an element in a video, so you don't need to recut the selection in each frame?]
[edit 2: I've found the base of the response to my question in rotoscoping and keying. (so many things to learn! This is wonderful!)
Adobe After Effects * Compositing and transparency overview and resources