For top quality for compositing it seems like you should: 1) Output as image sequence in Targa 2) Open Quicktime Pro (if you buy it) and click I believe its file->load image sequence 3) Load you images... if you open just 000 if I remember correctly it should load ALL the images in correct order. 4) Export the movie as Movie with "Millions of Colors +" as the setting. That will allow you to have a movie with an alpha channel to use in Adobe After Effects. (Great quality, and the film is already keyed out accurate to whatever level antialiasing you chose)