I'm trying to use this render as an overlay on an image in Photoshop. I tested blend modes in photoshop, but didn't get the result I was looking for. When I set the alpha to transparency in the scene settings it just rendered the object but not the bloom.
This is the expected result but the black would be transparent:
When I do set the alpha to transparent I get this w/o the bloom:
Right now it isn't possible to render bloom on a transparent background, because the render results use premultiplied alpha.
So, what are some other methods of creating bloom on a transparent background that doesn't involve compositing in blender. I don't care what program I have to use to solve this problem.