Do the blips occur at cuts?

Any pattern to them at all?

I was going to ask the same question as dxdy -- do the blips occur at cuts?

If the problem were a frame or two of gap between the clips in your background footage, then you wouldn't see green -- you'd see black in your background.

If you're seeing the green screen, then it sounds to me like on the green screen clip, somehow the composite effect was animated using keyframes, and the effect either ends a frame or two before the end or starts a frame or two after the beginning of the clip.

Look in the properties for the Chroma Keyer effect. Check to see if there's an extra 'diamond' somewhere that's just a frame or two away from either end of the clip.

This can happen if the 'Sync Cursor' option is set and the cursor on the timeline isn't at the absolute beginning frame of the clip you're applying the effect to. This will create a keyframe point in the clip effect that corresponds to wherever the timeline cursor is sitting.

If you find a 2nd 'diamond' a frame or two away from the END of the clip, just delete it. You shouldn't need to re-create the effect.

If the only 'diamond' you see is at the beginning of the clip, then use the "Zoom In Time" ("+") button on the effect to expand the keyframes line. If you keep clicking, I'm betting you will expand to a point where you will see a 2nd 'diamond' close to the beginning of the clip.

If you find a 2nd 'diamond' a frame or two away from the beginning of the clip, just delete it, move your cursor to the absolute first frame of the clip by clicking the 'First Keyframe' button, and re-create the effect.

An easier way is to click the 'First Keyframe' button, which will put your cursor on the absolute first frame of the clip. Then click the 'Next Keyframe' button. Chances are you won't notice any movement of the cursor, but if you look at the 'Cursor Position' box it will no longer read "00:00:00:00" -- the last digit or two will have changed. Now click the 'Delete Keyframe' button. If my guess is right, your composite effect will disappear and you'll see green screen rather than your background footage. If so, this means you had a hidden 2nd keyframe that was just a frame or two away from the beginning of the clip. Now click the 'First Keyframe' button and re-create your effect.

Hope that helps!

Thank you all, for the thoughtful responses. The "blips" were definitely not at cuts, as the background is one continuous clip. And, as mentioned in my original post, when rendered out to a .mov file, everything looks good.

I will check this out further, tonight.

Your original post refers to the green screen 'showing through'. That's technically not correct. Remember that the green screen is a part of the foreground clip -- it's the background clip that 'shows through' when the compositing is done.

The background footage being a continuous clip isn't relevant -- if it weren't a continuous clip and there were gaps between individual clips, then you wouldn't be seeing green flashes, you'd be seeing black ones, since black is the default background. The compositing would still be intact.

If you are seeing flashes of the green screen, that means that either there are gaps between clips, or perhaps overlaps of the clips, in the FOREGROUND footage, or the compositing is being lost momentarily for some reason. I don't know why that would only occur on .MOV renders, though.

It might not hurt to uninstall/reinstall Quicktime, or update it to the latest version.

Sounds like the result of an unregistered plugin.

geoff

Thank you, Bliss and Geoff. You are correct in that I mistakenly said green screen was showing through. I should have said, flashes of green appeared.

There are no breaks in the green screen clip. It is one continuous take.

I am not aware of any unregistered plug-ins, (I assume you mean registered with the company that produced them.) Whenever I have a plug-in that may be unregistered, a large "X" appears over that clip in the timeline. I had a few awhile back, as when I replaced my hard drive, I had to go through the whole process of registering again.

Looking to see where I can post a screen shot here.