I couldnt find an answer to this problem in previous forums. I accidentally shot 1080 24p and need to slow mo it in FCP (I know I prob should have shot in 1080 60i.) It doesnt look very good in post when i slow mo the 24p. Is there any fix in FCP for making this slow motion look more natural? Would i need to de interlace it or something? If so, how?
Did you shoot 24p or 24pA, are your clips coming in as 23.98 or 29.97?
There is nothing to deinterlaced cause your footage is already progressive. If you shoot 24p and have 29.97 you need to remove the pull down.
As far as SloMo, you can try using Motion it will do a better job if you render with best (optical flow) settings on. IF that doesn't work look at some 3rd plugins. FCP by itself doesn't do a good job at all.