Moving Background after Roto in AE

Hi,
I'm using Ryan's video tutorial method to create lightsabers in AE. The problem is, after I create the effect and render it out, the video behind the blade is bouncing up and down.

It also happens whenever I try and do a clone. One video will be steady but the one behind it bounces up and down.

How can I fix it?

Thanks for any help,
Bohh

 

Are you accidentally keyframing background positions on your video stream? If so, "lock" the background video by clicking on the little icon that looks like a padlock. Also, make sure you are only keyframing the solid's mask shape - not the position or anchor point.

Either that or you've got jittery video source from handheld cameras? If so... a tripod or a steady cam would probably help.

-Spiff

 

Yeah, but if the handheld camera was jittery I wouldn't think that would would mess up his rotoscoping.

 

The camera was on a tripod. And I'm positive that I didn't keyframe any moves to the background.

=/

 

Maybe---and just maybe---it's an interlacing issue?

 

Not sure, how would I go about testing that?

It's strange. I have access to a Mac sometimes, and when doing the same things on the Mac the jitters do not occur. But, when I do it on my PC...they always happen.