Hello,
I am currently using a Canon Rebel T3i. It is very similar to the T2i. I had set my camera to the 60 fps shooting mode because I intended to use slow motion. When I imported it to Final Cut Express I slowed down the clips to 40% for a smooth 24fps slow motion but when I went to view it I could clearly see that it was playing at a slower frame rate than 24fps. It appeared that it was playing my 60fps clips at 25 fps regardless of speed, which kind of upsets me seeing as how my video is 60fps. A similar thing happened in After Effects. Please help.
It seems to me that you're doing it wrong. You can't bring 60p directly into 24p timeline. If you do that, FCP will just convert the frame rate by discarding the extra frames. When you slow clips down, it will slow the frame rate down (i.e. duplicate frames needed to make up 40% more). You need to conform 60p to 24p. Open Cinema Tools and do a batch conform of all 60fps files to 24p, then import those into FCP and they'll playback at 24 fps in slow motion.
Flim Riot has a good tutorial video on this, both for After Effects and FCP:
