I've done it in the past but that was a very long time ago. I made a 600 frame clip that I exported as a QT movie to my desktop. Now I would like to export it again but with an alpha channel. The only problem is that when I go to the save output and reach the window that asks you to check the 'alpha' channel, it is grayed out. Not sure why or what I should do.
Also, since I will be importing this into FCP for an HDV sequence, do you have recommendations for the best compression to pick. Its default is 'video'