Render Pass

I am trying to render passes from my Blender animation to be used in an After Effects composite. When I try to render a specular pass it won’t render with an alpha channel. When one is rendering the specular pass is there any way to only render the specular data? The rest of the stuff in the scene I render comes out as a black.

You don’t need alpha for a specular pass. In AE you should set the spec layer to the “screen” blend mode.

That said, you can use the compositor to add alpha: