Exporting green screen with Alpha Channel background

Following keying out the green I need to export my subject in front of an alpha channel background so an outside effects house can lay the subject onto their background effects. Is there a way to export with an alpha channel background?

Why not send them the raw footage and let them do the keying? I hear effects houses are pretty good at that. None of the places I send footage to would want it pre-keyed.


www.shanerosseditor.com

Listen to THE EDIT BAY Podcast on iTunes
[itunes.apple.com]

They just do Flash and have made it clear that I am responsible for the keying

> Is there a way to export with an alpha channel background?

Not my specialty, but there have been previous discussions about exporting with an alpha channel and I believe the method is to export the movie file without rendering first.


www.derekmok.com

Second time today I have recommended VectorKey. This is from thier manual I was just reading this morning.

"Step 11: If you want to generate a traveling matte (luma version), you can check
the Generate Mask option, and export a grayscale video that can be applied to
your video as a traveling matte. The reason you might want to do this, is so that
you can rotoscope the matte, where keying or garbage matting are impossible.
Also, many video codecs won?t store an alpha channel, so keeping the matte as a
separate video allows you to store it for use in non Quicktime applications. "

You an find the program here. [www.oakstreetsoftware.com]

Oh - sorry, reread that and you need an alpha channel, not a travelling matte. Choose an export codec that will accept alpha - it will have a 'millions+' option. Then export without rendering.