Shooting slow motion with camcorders: frame rates and post-production

Reader’s question:

I have a question which is related to both camerawork and editing. Actually I am soon going to shoot my first independent movie. I have plans for some slow-mo stuff. But I have read that slow-mo needs 60 FPS footage. But I cannot afford buying a camcorder now. I have a camera which can shoot at 30 FPS. So what goes behind using 30 FPS for slow mo?

My answer:

I am not sure that your camera will actually shoot slow motion — it just sounds like regular NTSC footage to me. In any case, even if it is true 30fps, when played back at 24fps, it will be slow, but not that much slower than 24fps.

Basically the way real slow motion works is by shooting at a frame rate higher than 24fps, and then playing back at 24fps.

For example, if you shoot at 48fps and play back at 24fps, the footage will be twice as slow.

This needs a camera that can shoot at higher frame rates.

The only alternative when using regular cameras is to shoot as normal, and then slow it down in post-production. This results in jerky slow motion, but it can have a charm of its own. For smoother results, you can use a plugin that will interpolate the extra frames needed for the slow motion effect.

Remember that if you make a shot twice as slow, it will occupy twice as much time on the timeline — it’s obvious, but if you are editing to strict duration (such as with TV spots), you should bear it in mind.

I hope this helps!