You need to render the file 32bit. In the Output Module section of the render queue make sure that you have chosen a format that supports alpha channels such as TGA or Quicktime Animation codec. Choose the RGB + Alpha option for “Channels” and this will give you a “Depth” of millions of colors+. Render out and you should be good to go 🙂
JD
John Dickinson
Motionworks
http://www.motionworks.com.au