I created a short 10 second clip yesterday that I need to export to a Quicktime movie. It has an alpha channel but as far as I can tell, I am unable to render out both the video and the alpha channel at the same time (I can only render out one or the other). Does anyone know if it's possible to render out a movie with Alpha Channel and if so, how ? Thanks.
Yes, it's possible, but only using certain codecs. One of the most common choices is the QT Animation codec. Choosing the "Lossless With Alpha" output module on a Mac will create exactly that.
Post more info about your hardware, OS and requirements if you want a customised explanation.