i am doing a sky replacement. i traked in mocha but when in import it the sky seems to be shaky but when i use the same track to add someting else it dosnt move so its probably something to do with paralax. my question is when doing sky replacemnt, should i track (n Mocha) the farthest away plane from camera or the closest plane from camera?
When tracking, you want to choose a point that is on the same (or similar) plane to the thing you are working on...
So for a sky, choose something WAY back. Since the sky is so far away, to our eyes, it doesn't really move much in response to the camera.
I guess it could be different for things like large patches of cloud closer to the viewer, but even that may not be, not really sure.
If there is any horizon detail (far off trees, buildings, etc) they are good options.