Frame rate change affecting specific effects
by Paul Holub on Aug 12, 2016 at 3:42:32 pm
I'm going to try to explain this as simply as possible.
I have some clips I am adding effects onto (rotoscoping, travelling masks, etc) all very dependent on keyframe placement and time during said clip. I accidentally made all of these effects using 30fps. The video I am working off of and want to export with is actually 23.98 FPS. Once I change the FPS of the composition, all my effects are slightly off in terms of timing and therefor are out of place. Is there a way to make my effects conform with the timing? Maybe a time-stretch or something? Any help is appreciated.
Re: Frame rate change affecting specific effects by Dave LaRonde on Aug 12, 2016 at 6:50:12 pm Last Edited By Dave LaRonde on Aug 12, 2016 at 10:12:49 pm
There are a few things going on here:
It's not a good idea to render 29.97 footage in a 23.976 (NOT 23.98) timeline; the frame rates won't match up, and the motion will be screwy, moving in fits & starts. It is a FAR better idea to do a frame rate CONVERSION, where software takes adjacent frames of 29.97 footage to create the motion of 23.976 (NOT 23.98) footage.
You're kind of stuck with the keyframes you have at the original frame rate. But if you haven't messed with the project too much, you can change the comp frame rate back to 29.97, render out in a lossless codec, and then do a frame rate conversion to get it to 23.976 (NOT 23.98).
Oh, I almost forgot -- in AE, the frame rate to use is the actual frame rate of the footage. Thus, 30 footage should be 29.97, and 23.98 footage should be 23.976. AE is very picky about such things.
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