Slow motion works by recording more frames each second than the clip will later play, so the action stretches out. Shoot at a higher frame rate, give the scene plenty of light, and slow the footage on a timeline set to a normal rate. Here is how each part fits together.
How Frame Rate Creates the Effect
Normal playback is often 24, 25 or 30 frames per second. If you record at 120 frames per second and play it back at 30, the action runs four times slower. A higher recording rate means a smoother result at a given slowdown, while a lower rate leaves visible stutter.
| Recorded at | Played at | Speed |
|---|---|---|
| 60 fps | 30 fps | Half speed |
| 120 fps | 30 fps | Quarter speed |
| 240 fps | 30 fps | One eighth speed |
Shooting Steps
- Choose an action worth slowing: a jump, splash, hair flip, pour or a ball in flight.
- Switch the camera to its high frame rate mode. Check the manual, since some modes lower the resolution.
- Set the shutter speed to about double the frame rate, for example 1/250 second at 120 fps. This keeps motion crisp without too much blur.
- Add light. Short shutter speeds let in less, so shoot outdoors in daylight or add bright lamps indoors.
- Steady the camera on a tripod or a firm surface, because shake is amplified when the footage is slowed.
- Record a bit before and after the action, so you have room to trim.
- Repeat the action several times, as it passes in an instant.
Slowing the Footage
Place the clip on a timeline that runs at a normal rate. Apply a speed change, or let the editor interpret the clip as normal speed. Mix speeds for impact: normal pace leading into the action, slow during, then back to normal. Ease the speed change instead of jumping, and add music or quiet sound since slowed audio rarely sounds good.
Common Problems
- Flicker under indoor lights, caused by the light’s own pulse. Try a different shutter speed or move outdoors.
- Grainy footage from low light. Add light rather than raising sensitivity.
- Choppy look when slowing standard footage. Use true high-frame-rate footage when you can.
Plan for storage as well. High frame rate clips make large files, so keep short takes of a few seconds and clear space on the card first. Rehearse the action once without recording, so the person or object is in the right place when you press the button.
FAQ
Can I make slow motion from normal footage?
Editors can create in-between frames, but results are less clean than footage recorded at a high rate.
Does slow motion record sound?
Often it does not, or the sound is slowed too. Add sound in editing.
The Short Version
Record at a high frame rate with a fast shutter and strong light, keep the camera steady, then slow the clip on a normal-rate timeline.