output alpha different from VFB

[sailor]

Hi,

I saved EXR and noticed alpha output in Photoshop looks different from Corona VFB. Is it still normal behavior?

I found other thread that in order to get the same results I need to add alpha element in the render setup and save it png but it's too late now, I rendered without it. How can I get proper alpha?

[romullus]

Try to apply gamma 0,4555 to your saved alpha channel.

[sailor]

I did it and it looks fine on its own layer but saved it into Alpha channel, it's still lighter.

[maru]

It means it was saved or loaded with incorrect gamma. To fix this, you either need to apply gamma 2.2 or 0.45 as Romullus mentioned.
If you are using some proper compositing software (i.e. not Photoshop), it should offer one-click options correct gamma.