Bloom effect with a transparent background? 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. 

Thanks.
I have tested many different combinations.
The best way to achieve it is to use post compositing.

With cycle follow the node setup with red arrows.
I also tried EEVEE, there is a BloomCol pass that you can check,
but this pass does not have tranparency, so using this or doing an alphaover node would kill your transparency. It does look fancier out of box.

but for transparency I think cycles is easier.
I am sorry if it looks messy, as I just figured it out, so I do not want to destroy my node setup.