Rolling shutter
Also known as: rolling shutter effect, jello effect, skew distortion
Rolling shutter is a distortion that appears when a camera sensor captures an image line by line instead of all at once. Fast motion can look skewed, wobbly, or smeared because different parts of the frame are recorded at slightly different moments.
- From sensors that scan line by line
- Skews or wobbles fast motion and quick pans
- Reduced by faster readout or a global shutter
How it happens
Most phone and consumer cameras use a CMOS sensor that reads the scene by scanning rows from top to bottom in quick succession rather than freezing the whole frame instantly. During that brief scan, anything moving fast — a passing car, a spinning fan, the frame during a quick pan — ends up recorded at a different position on each row.
The result is leaning verticals, a "jello" wobble in handheld video, or warped propeller and wheel shapes. A faster sensor readout reduces the effect; a true global shutter, which exposes every pixel at once, eliminates it but is rarer and more expensive.
How to limit it
Pan and move the camera more slowly, brace or stabilize it, and avoid whipping past fast subjects. In-camera or software stabilization can also help mask the wobble in video.
Rolling shutter is a capture artifact, not a storage one — it affects how motion looks, not file size, which is driven by resolution, frame rate, and bitrate.