Skip to main content
Jes2000
Known Participant
July 3, 2018
Answered

Alpha Channel Not Working

  • July 3, 2018
  • 4 replies
  • 17137 views

I rendered a QuickTime move today RGB+Alpha in After Effects and imported it into the Premiere to layer on top of another file. It does not show at all on the timeline though I can scrub through it just fine in the source Window. I know Adobe dropped support for older codecs, but I have the latest updates for both programs. Shouldn't they be equipped with the latest codecs?

This topic has been closed for replies.
Correct answer Carlos Ziade

try to go to 'Project Panel', from there right click on your .mov file - modify - interpret footage

and under Alpha Channel try to toggle between use alpha premultiplication from file and

conform alpha premultiplication to premultiplied alpha ... when dropping your .mov file into

the timeline right click on it and set to frame size

check if that helps

if it doesn't try exporting from After Effects as PNG / RGB + Alpha

4 replies

Participant
April 14, 2022

I just realized what I was dealing with. My ingest settings were creating proxies that didn't have an alpha channel.  Detaching proxies for those files brought them back.

Participant
September 2, 2024

This saved me.... I had transcoding activated. You're a hero

Carlos ZiadeCommunity ExpertCorrect answer
Community Expert
July 4, 2018

try to go to 'Project Panel', from there right click on your .mov file - modify - interpret footage

and under Alpha Channel try to toggle between use alpha premultiplication from file and

conform alpha premultiplication to premultiplied alpha ... when dropping your .mov file into

the timeline right click on it and set to frame size

check if that helps

if it doesn't try exporting from After Effects as PNG / RGB + Alpha

Jes2000
Jes2000Author
Known Participant
July 5, 2018

Thank you.  I will try this in a second.

Legend
July 4, 2018

Are the QuickTime file and sequence set to the same resolution?

Jes2000
Jes2000Author
Known Participant
July 5, 2018

They are

Ann Bens
Community Expert
Community Expert
July 3, 2018

Alpha shows as black if you do not have any clip or whatever underneath in the timeline.

Check if the clip has alpha in the Preview Area.

Jes2000
Jes2000Author
Known Participant
July 5, 2018

It does