ProRes 4444 alpha channel purple fringe in latest versions!
The last two updates to Premiere have introduced a bug where ProRes 4444 material with blended transparency are getting weird jaggy colorful fringes where transparency steps from 0% to 1%. Unfortunately I can't just turn off max depth, because the result introduces banding to those same transparency areas.
I did find a workaround… I added the Ultra Key and set the key color to something extreme that appears nowhere in the graphic, like Green 100% bright. This causes the fringe to disappear. Other effects like Remove Matte also seem to get rid of of by dumbing down the bit depth on just that one layer, but they introduce some undesirable banding in the process.
Jonathan Gifford commented
I always render Alpha in Straight, but the problem happens to me too. Turning off "Composit in Linear Color" in the sequence settings panel fixes the problem for me. Nothing else needed assuming you're already feeding in Straight Alpha (which you should do anyway otherwise you can have other edge artifacts).
Manny Castillo commented
I just payed attention to the AE export settings so this is where you can change it to Straight when exporting from AE to avoid that issue in PR. File sizes will be larger though.
Ithyle Griffiths commented
Manny Castillo's answer was what worked for me!! Thank you Man!! You just saved me hours or re-exporting clips from AE.Which is what I was doing with good results but then PR decided to change which clips it wanted to add fringe to and I almost lost my mind.
Tyler Boren commented
Hey! Oddly enough, exporting Straight (Unmatted) with RGB + Alpha Channels selected in Apple Prores 4444 fixes this problem. I'm so surprised. It even interprets the motion blur correctly. So you don't have to interpret footage, none of that-- just export with Straight (Unmatted) activated.
I use the Render Que for this one (File>Add to Render Cue).
Francois Karstel commented
Thank you Manny, it also worked for me. The weird thing is, Premiere does not seem to have the same effect on the alpha consistently, because I am only having this weird blue halo in my one project's components - is it the export settings from After effects I applied when making these layers to use in Premiere?
Chase Smith commented
Manny's solution worked for me! But there doesn't seem to be a way to change the default setting, so I'm doing this for all alphas individually...
Manny Castillo commented
This helped me:
-On the project window (not on the timeline) Right click on the clip with 4444 alpha and select "Modify" > "Interpret Footage".
-In the Alpha Channel section, by default "Use alpha premultiplication from file" is selected. Change it to "Conform Alpha Premultiplication" (no need to select anything else).
Would be nice that it either is selected by default in PR or that it's exported automatically like that from AE. Anybody knows how?
Simon Blervaque commented
I have it too ! Very annoying, please change it as soon as possible