Slow Motion

Capture fast, play slow. That's the whole idea.

The principle

Leave the playback fps unchanged on the timeline; raise the capture fps. The same event gets recorded across more frames, so on a 24/30fps timeline it plays back proportionally slower.

Slow-motion ratio = capture fps ÷ playback fps

Lowering fps for slow-mo? — No

Easy to confuse.

• Capture at lower fps → time gaps between frames widen → fast motion turns into a stuttering time-lapse.
• Capture at higher fps → finer time slices → playback unrolls slowly.

Slow motion is about slicing time finer.

The shutter rule applies to "capture fps"

The 180° rule still holds for slow-mo, but recompute it against the capture fps.

→ Higher fps capture = faster shutter = more light required. That's why slow-mo usually needs to happen in bright environments. It's also why indoor slow-mo is hard to expose properly.

Common mistakes

1. Leaving shutter alone while raising fps — Shooting 60fps with 1/50 shutter is effectively impossible (shutter angle would exceed 360°), and the camera will silently shorten it. The look ends up off.
2. Wrong timeline fps — Putting a 120fps clip on a 120fps timeline gives no slow motion. The timeline should be 24/30, only the clip 120.
3. Not enough motion blur — Slow-mo with very fast shutter looks unnaturally jittery because each frame is too crisp. Unless that's the point, keep the angle near 180°.

Practical examples

• 120fps + 24fps timeline — the most common 5× slow-mo. Good for human movement, water droplets, sports.
• 240fps — claps, fast hand gestures, splashes.
• 1000fps+ (specialized gear) — bullets, balloon pops, advertising.

Related

• frame-rate-and-shutter-angle — Parent note
• frame-rate
• shutter-angle
• shutter-speed