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Freeze frame with alpha – black outline!
Hello
I know this has been covered (kind of) before: the subject of comping something with an alpha on a background gives a dark outline; solution: your footage is probably premultiplied with black, so set the alpha to ‘black’.
So far so good – I have some premult’ed footage, I set the alpha to black, and it looks great. But if I do a shift-N freeze frame to extend the start of the footage+alpha, it gives me the nasty black outline, even if I then set the alpha of this newly created still to black.
OK – so plan B, re-render the graphics (from After Effects) with the alpha set to ‘straight’. Re-import it into FCP (after deleting everything using the render manager so there’s nothing nasty hanging around), plonk it on the background and it looks lovely – with the alpha set to its default ‘straight’. So, I do another shift-n – and lo and behold here’s that horrid black outline! No matter what I set the alpha to, the black outline is always there.
And it doesn’t matter if I double-click the graphics layer from the timeline and then do the shift-n or double-click the footage in the browser, then do shift-n; I get the same result.
A bit long-winded, but I hope someone out there might have the answer! I think for now, I’ll just output a separate still frame for the start and end of each of my graphics sequences and bring them into FCP. What are the chances of the gamma levels being the same as my QuickTimes? About zero, I think!! (Zero chance, that is – not zero gamma!)
By the way, I’m using After Effects’ ‘Lossless’ (Animation codec – which will be celebrating its 20th birthday this year!) with Channels set to RGB + Alpha, with a Straight alpha.
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2 Replies
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I always use straight and never have a problem. But sounds like you’re trying everything there is. Make sure the graphic is set to straight, then make a freeze frame, then make sure that graphic is set to straight.
Also try prores 444 instead of the old animation codec.
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Ah – I suppose the clue was in my original post…I switched to the young spring chicken ProRes 4444 and retired the elderly Animation codec and voilà – problem solved. Kind of silly of me not to do that in the first place, especially as the background footage (and the FCP sequence) are ProRes 422 (HQ)!
Thanks, Bret for the suggestion!
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