The company I work for is trying to do a film where some scenes take place in Iraq and were shooting test footage at some local sand dunes/sandpits to see if it will pas for Iraq. The scenes that we've filmed at these sandpits look like they could, however, the trees in the background ruin the illusion. If I could remove the trees and just show a clear blue skyline and sky instead it would be perfect. My partner and I first tried to do motion tracking in Abode but the motion in the sky and the ground was off when we tried it. Then we tried a reverse matte where we took the same scenes, blew up the sky, and then put that scene underneath the original scene in the timeline (putting a hole in the original clip via the 8-point matte [V2], placing the blown up clip on V1, then moved the skyline from the blown up clip in the hole). Again, the sky's grain was inconsistent with the ground in the rendered clip (because of the blow-up) and it looked like the sandpit was in the mountains because the cloud were too close to the ground.
We're running out of ideas and I was wondering if anyone else had any suggestions as to how to remove a skyline with trees from a clip without it looking too tacky. Let me know; thanks.
Yes, that will work, though tedious. You can use the "extract" effect in photoshop to speed the roto job along, in combination with a batch action.
If it was me, I think I'd track the footage in Apple Motion first, then apply the motion tracking file to a stack of tracks of the ground shot and one of a sky shot, *then* use the masking tools between them.