Bloom & glare workflow with premultiplied EXRs & denoiser

[busseynova]

Can someone help me get my head around the best workflow here, I have a work-around, but not sure it's the best way of doing things.

So I have a render - with glare effects applied, and I'm also using denoiser. My rendered EXR has, amongst others, a Glare channel, and an Effects results channel, which consists of the denoised image plus the Glare.

When I bring this in to my post production programme (AE) the glare is clipped by the pre-multiplied alpha.

The only work-around I can think of is to use the pre-multiplied image, then bring an additional copy of the same image in without the alpha, subtract the glare (with alpha) and add it in again (without alpha). This seems like a really messy workflow an means having two instances of each sequence in AE, one pre-multiplied and one not.

It would, at least, be handy to have a denoiser channel, exclusive from the glare effects. Or have the option to add the glare to the alpha, although I'm not sure this would work correctly when compositing.

[vaya_studio]

busseynova you should set the Denoiser's mode to "Show denoiser result chanel" to get it as a seperate pass without all the post effects in it like the "Effects result". When adding your footage in AE set it's Alpha to "Straight - Unmatted" so it keeps the information of the transperant pixels, precompose your effects result and glare pass with difference blending mode (add levels to both passes and adjust the black of the alpha channel to be white so you don't get clipping). That way you'll have the glare effect separated and add it to your composition while having full control over brightness and color and you can use masks as well.

[busseynova]

busseynova precompose your effects result and glare pass with difference blending mode (add levels to both passes and adjust the black of the alpha channel to be white so you don't get clipping). That way you'll have the glare effect separated and add it to your composition while having full control over brightness and color and you can use masks as well.

Thanks. I had missed that option in the Denoiser settings., Isn't the above unnecessary though? I've got a separate Glare channel in Vray5.