• Apple Final Cut Pro Legacy

  Alpha channel problem

  Posted by Ariane Mertz on June 24, 2009 at 2:15 pm

  I am having an odd alpha channel problem.

  I created a small animation in After Effects with transparent background and followed all the proper settings (Quicktime animation, lossless+alpha, RBG+alpha, million+ colors ect.)

  I know the file has the proper alpha channel because I sent it to a friend who was able to insert it into the timeline with proper transparency in his FCP.

  When I do it on mine, I get a black background on my animation covering the video I was trying to overlay. I tried it with both alpha “straight” and “premultiplied”. In “composite mode: normal” I have a black background. In other composite modes I can see the video below but to unacceptable effect.

  Does anyone have an idea what might be going on here. Why would my FCP behave so strangely.

  AE 5.5
  FCP 5

  Thanks!

  Ariane Mertz replied 17 years, 2 months ago 2 Members · 3 Replies
• 3 Replies

• 

  David Bogie

  June 24, 2009 at 3:54 pm

  In the Browser, load the file into the viewer. Use the view selector choose Alpha only. What do you see?

  bogiesan
• 

  Ariane Mertz

  June 25, 2009 at 12:12 am

  Thanks for the reply bogiesan

  Not sure what you mean by “view selector” but when I load the clip into the viewer and turn on the checkerboard background, I see checkerboard when selecting view > Channels > RGB+Alpha.

  I see everything black that should be transparent when selecting view > channels > Alpha.

  Which means the clip is as it should be.

  Any ideas why the clip background goes black when loaded into the timeline?

  Thanks
  Ariane
• 

  Ariane Mertz

  June 25, 2009 at 2:23 am

  Ok, now I discovered something interesting.

  If I open the animation into the viewer from the browser
  view > channel > alpha (only) will give a black background
  view > channel > alpha + RGB will give a checkerboard background

  As described in my earlier posting.

  BUT

  If I open the same clip into the viewer from the timeline (after I have dragged it there)
  view > channel > alpha (only) will give a white background
  view > channel > alpha + RGB will give a light red background

  Is it normal that this would change like that just by dragging a clip into the timeline?

  Thanks
  Ariane

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