to download the movie, right click here.
how to use 60p footage as slow motion 30p in final cut pro
a simple but slightly roundabout technique
The movie above uses footage from a camera shot at 60 frames per second (fps) in progressive scan mode. The movie plays at 30 frames per second and parts of the orignal footage are slowed to 50% to give smooth slow motion. Essentially it's like an overcranked film camera.
However, it doesn't seem to be as simple as dropping a 60p clip into a 30p (29.97 to be exact) timeline and changing the speed to 50%. This technique renders a clip that plays every second frame twice, rather than drawing upon that extra frame that is really there (because the original frame rate is twice as fast).
Here is one way to fix it:
- Make a new sequence with the editing timebase set to 59.94.
- Drop your 60 fps clip into it.
- Set the speed of the clip to 50% and turn off Frame Blending. This gives you a 60 fps clip where every frame plays twice.
- Export the timeline as a 30fps, self-contained movie. To do this, make sure you choose a preset that is 29.97fps and compatible with the rest of the clips you are editing, i.e., DVCPRO NTSC.
- The file it creates is now 50% of realtime, with 30 real frames per second.
Note: this technique should work for interlaced video at 60fps - just add a deinterlace filter before exporting the 30fps clip.
posted: January 24 2009 02:28:50.