Why does "think different" so often not translate to Think Better?
FCP has a big bug in it's workflow for anything smelling like 24 frame video. There aren't that many cameras shooting 24 FPS (were not talking "24P" which shoots 23.97 FPS, not 24 as the name implies). But there is one that is being used more and more and that is the Canon 5D Mark II. It's a still camera that can shoot video, but only 30 frame video. Why???? WEll it was just supposed to be for the web. Indi filmmakers live up to the Apple slogan and they started shooting films with the 5D Mk II.
For those that don't know there are only two uses for 30FPS footage. The first is for B&W TV in the 50's (not a lot of call for that now) and the other is in the FILM to VIDEO transfer process. It gets complicated but US Video runs at 29.97 FPS and FILM at 24 so they copy the film frame for frame (with a few dupes) to 30 FPS video and then slow it down a touch.
Anyway FCP sees 30 frame video goes"hey that's really 24 and I thinks (for you) that this is film transferred to video so it's slowed down and any sound you might want to add I will slow down also so everybody's happy. Unless of course you thought differently and didn't shoot film and bring it into FCP. And if your camera doesn't do a great job of recording audio so you want to record separately well then you have a problem. Because FCP will change the speed of ANY sound file you bring in to the sequence.
And if you do audio post... Well then it really gets interesting because nobody but FCP "Thinks for you" on this topic and those clips that wouldn't stay in sync in FCP are fine in say Pro Tools. Until you send it back to FCP! Of course if you spent time re syncing all those clips in FCP, they are all off in PT (or anything other than FCS).
So what to do?
The trick it turns out is to wrap your WAV file in a MOV wrapper and tell FCP that the package is 24 FPS, so it will leave it alone.
The only smooth way to do that is with
Sebsky Tools. It's free but it was made by a studio that went under so it's hard to find. I will put it on my site in the files section and add a link here if it's not simple to go there.
There is an ongoing thread on this issue on the DUC. and it's late but I'll go over how to use S.T. next post.