The difference is timing. A global shutter captures every pixel in the frame at the same moment, while a rolling shutter scans the frame row by row over a short time. This only matters when the subject or the camera moves quickly, or when light changes during the exposure.
Two Ways to Capture a Frame
Think of a rolling shutter as a scanner passing over the scene. Each row is a little later than the one before it. A global shutter is closer to a single snapshot, where the whole sensor begins and ends together. The time a rolling sensor needs to scan the full frame is called the readout time, and shorter is better for avoiding artifacts.
What Rolling Shutter Looks Like
- Skewed verticals: a fast pan makes buildings or poles lean.
- Bent propellers and wheels: spinning objects look warped or curved because each row sees them in a different position.
- Wobble: shake from a vehicle or a drone can create a jello look in video.
- Flash banding: a brief burst of light may brighten only part of the frame.
- Light flicker bands: LED screens and some lamps show dark stripes when the shutter speed does not match their flicker.
When It Is Worth Caring
| Situation | Rolling shutter risk |
|---|---|
| Sports and fast pans | Noticeable |
| Drone and vehicle mounted video | Noticeable with vibration |
| Photographing LED screens | Banding possible |
| Portraits and landscapes | Rarely visible |
| Tripod interviews | Rarely visible |
How to Reduce Rolling Shutter
- Slow down pans and keep camera movements smooth, or use a stabilizer.
- Use a mechanical shutter for stills of fast action when your camera offers it.
- Choose a camera and video mode with fast readout. Some high-resolution modes read the sensor more slowly.
- Match your shutter speed to the mains frequency when shooting under artificial lights, for example 1/50 or 1/60 as a baseline.
- Fix vibration at the source with a better mount or dampening.
Is Global Shutter Always Better?
Not always. A global shutter solves the timing issue, but sensor designs have other trade-offs that can affect noise or dynamic range, and these vary by model. Cameras with a very fast readout can look nearly free of rolling shutter in daily use. Judge a camera by sample footage and the maker’s description of its sensor, not only by the shutter type.
FAQ
Does a mechanical shutter have rolling shutter?
A mechanical shutter exposes the frame with moving curtains, which is a different effect. It does not scan electronically, but it has its own flash sync limits.
Why do some phone videos look wobbly?
Many phone sensors scan relatively slowly and are held in hand, so shake becomes visible. Better stabilization and faster sensors reduce it.
The Short Version
Global shutter captures the whole frame at once, and rolling shutter reads it line by line. You will notice the difference mainly in fast action, vibration, flash and flicker. For slower subjects, either type works well.
