image matte trouble

[jeffmunchow]

I am currently experiementing with doing split screen with a gradiant image map so that the line is not apparent so that the 2 takes go togeather seamlessly. what i am trying to do is have the same person twice in a shot and it was going well, when i did a real time preview of it it looked fine but when i try to render or export 20% of the screen gets chopped off of the top layer exposing the bottom layer and ruining it, so what i am wondering is why the program chops the frame and what i can do to fix it because it is very very very frustrating

 

[overnighttolondon]

Things to check:
- the dimensions of your image matte (should be 720x480 for NTSC or larger)
- the position of your clips (360, 240)
- you can try doing a track matte instead, dropping the image onto a track that you hide for the composite. You can show the track though while you're setting things up, giving you more control over the position and dimensions of the mask