Particles with motion blur alpha issue

[stevesideas]

I've attached 2 images. First is render direct from vray, second is imported EXR (32 bit float with alpha). I lose a lot of detail in the image for some reason. Any way to resolve this ?

[^Lele^]

umh, it looks like double premultiplication.
Or, you have some CC in the VFB, absent in AE.
An EXR would be most welcome, though.

[stevesideas]

Here you go. I have just output as a exr with alpha on a black background. I then imported into AE which defaults to premultiplied. Not sure how it would be double premult ?

[^Lele^]

It seems to work in Nuke, and look similar what you have in AE if i premult it (see attached).

[stevesideas]

Hmm. So I only have the option to premult or straight the alpha. straight doesn't work. Premult just gives the result that isn't correct. Do I need to add an effect or something ?

[^Lele^]

"unpremult"?
Which is lingo for "divide" by the alpha.

[vaya_studio]

If you add a levels adjustment that influences just the alpha it gets almost identical to the original image.

[stevesideas]

Brilliant. That works well. Thanks