Different effect of blur at alpha

[dmstraker]

Don't know if this is a bug, but it does seem odd. See attached file.

Different effect of gaussian blur when at clipping child position vs. at mask child position.

At clipping position it gives dark effect at edges of hard alpha (including with Preserve Alpha) while at mask position it's more as expected (and same as when blur layer is above pixel layer).

blur on alpha.afphoto

[dmstraker]

Note: I tried it with latest beta 1.10.0.1127 and it's still happening.

[NotMyFault]

I found at least some consistency for adjustments and filters in their behavior:

• Nested to clipping positions, alpha gets ignored. Effect is only applied to RGB chanels
• Nested to masking position: Effect gets applied to all RGBA channels.
• For me, this sound reasonable.
• What I'm missing (and requested as feature) is a new 3rd nesting position where filters get only applied to alpha channel.
• It would be even better if users where able to select on which individual channels adjustments and filters get applied, e.g. only R channel. This could simplify lots of workflows, e.g. selective denoise on RGB channels, selective blur on alpha channel to feather a mask, selective min / max blur on alpha channel to shrink/grow mask, ...

 

[MEB]

Hi @dmstraker,
Thanks for your report. I agree that the dark edges effect is a bit odd. I'm logging this to be looked at.