possible to make an alpha background?

I was wondering if it is possible to render an animation with a transparent background?

I’m NOT looking for a greenscreen, which would be easy to create by simply setting the background color to green, but a way to set the background to an alpha (which will still pick up semi-transparent shadows) for overlay over other images or movies.

Any help here would be greatly appreciated!


In the ‘Output’ tap of the ‘Render’ settings choose a transparency supporting format (for example PNG) and change from RGB to RGBA.