I have a shot of hands reaching out to each other. When i shot it i didn't realize there was a box behind them with modren writing on it. i need to get rid of or somehow obscure the box. i'm working in After effects CS4 64bit. Do i have to go frame by frame and mask the hand and arm or is there a new way of doing this?
This is a perfect job for Photoshop, Mocha, and AE. You track the hand in Mocha and create a mask, you use Photoshop to clean up the bad frame and create a still you can put behind the hand, you copy and paste the mask to AE which is used as a track matte for a copy of the footage layer and you set up your comp like this.
Track Matte from Mocha
Copy of the Video (using top layer)
Photoshop fix of the sign
Your original video.
Here's a good tutorial on Roto with Mocha
Here's the first of a 2 part tutorial on exactly what you want to do using a much more complex shot.
You could also use the Mocha Remove tool if you have Mocha Pro. It's amazing but nothing you can't do by a little roto in Mocha and a little work in Photoshop.
Doesn't look too severe, so doing it by hand would not be too much trouble. In fact if you have never used mocha before, watching those tutorials and getting a grasp of the program might take longer than just sitting it through and doing it with AE masks over a nice cup of coffee...