Alpha renders look jagged
by victor kohler
on
Sep 9, 2008 at 7:11:28 pm
Hi,
I've got some graphics made in AE rendered to Quicktime with the animation codec. The graphics have an alpha channel that needs to be preserved for compositing with live footage in FCP. The problem is that my renders look great when viewed in QT but in FCP they look bad. The edges get jagged the entire graphic looks unsharp. I've tried renders with other codecs like PNG and uncompressed with the same issues. Im editing in a ProRes HQ sequence in FCP. Im not shure if this is an FCP or AE issue, thats why im doubble-posting.
Any ideas?
Im using:
Adobe After Effects CS3
Final Cut Pro 6.0.4
Quicktime 7.5.0
Re: Alpha renders look jagged by Jeremy Garchow on Sep 9, 2008 at 8:13:05 pm
[Chris Poisson]"I'd bet the farm your alpha is premultiplied. When you have a straight alpha usually they look terrible in QT and great in FC."
Yes, AE does default to render a premultiplied alpha. If this is the case, you Victor, need to change the alpha status to 'black' in FCP from the browser. If the clip is in the timeline already then you can right click on the clip and choose item properties > format, then change the alpha type to black from straight.
Re: Alpha renders look jagged by victor kohler on Sep 10, 2008 at 7:58:56 am
Now it works! My animation codec still looks bad but when i rendered it as a PNG sequence with pre-multiplied alpha and set the alpha interpretation in FCP to black it turned out very nice! Thanks for the help guys!
