How do I set the frames per secondframe rate (FPS) for a project in iMovie 10.2.3?

iMovie sets the frame rate of a project as that of the first-ever video clip placed into a newly created project. You can delete or replace the video clip later without affecting the project. If you want to change the frame rate of an existing project you need to create a new project and set the frame rate there.

— Rich

Frame rate is set to the rate of your first clips. So your clips are 29.97fps, not 30. (30 is often used as a shortcut for 29.97).

You don't want to be converting frame rate if you can avoid it. Frame rate conversion will always cause jerkyness in videos, and converting from 29.97 to 30 would result in adding roughly 1 frame every 1000, so you would get a jerk every 33 seconds or so. I would find that very annoying.

Hi, TonyCollinet,

Although I have not done personal testing, here is my understanding of frame rates: Decreasing, not increasing, the frame rate substantially can result in jerkiness. So playing a 60 fps clip at 30 fps can give a stutter. But increasing the frame rate substantially results in slow motion, not jerkiness. Increasing the frame rate a minuscule amount like from 29.97 to 30 fps I would think would not be visible to the human eye, and in any event should be smooth. I am looking at it as not adding a frame but playing the frames you have faster. (Possibly a small increase in frame rate could make a difference if precision were required to sync one clip with another video clip or with an audio clip.) That seems logical to me because playing more frames in the same amount of time should be smoother, not jerky. Have you observed differently?

-- Rich