Rolling shutter
An artifact of CMOS sensors that read pixels row-by-row from top to bottom. Fast-moving subjects appear sheared; flashes appear as bands. Affects most mirrorless and phone cameras.
In a rolling-shutter sensor, by the time the bottom row is read, the top row's data is milliseconds old. A vertical line panned horizontally appears tilted; a propeller appears curved.
When it matters
- Fast pans (sports, action).
- Subjects moving across the frame quickly.
- Flickering / pulsed lighting (LEDs, monitors in shot).
- Flash photography in high-speed sync.
How it's measured
Readout time, in milliseconds — how long the sensor takes to scan top to bottom. A Sony A1 reads in ~5 ms; a Nikon Z9 stacked sensor in ~4 ms; older mirrorless in 30+ ms.
Stacked sensors
"Stacked CMOS" designs separate the photo layer from the readout circuitry, allowing parallel readout and dramatically faster scan times. The Z9, A1, R3, and R5 II use stacked sensors and effectively eliminate rolling-shutter artifacts in most situations.
Phones
Computational photography stacks reduce visible rolling shutter by aligning frames in post — at the cost of pipeline latency.
How to use Rolling shutter in a real comparison
An artifact of CMOS sensors that read pixels row-by-row from top to bottom. Fast-moving subjects appear sheared; flashes appear as bands. Affects most mirrorless and phone cameras. In practice, this is most useful as one part of a decision rather than a standalone quality badge. Compare it alongside the workload, room, ecosystem, budget, and ownership constraints that apply to you; the strongest published figure is not automatically the best outcome for every buyer.
What to check next
Open a product page and check the stated value, configuration, price, and related trade-offs before treating this term as decisive. It is especially relevant in .
Avoid the one-number trap
Manufacturers can describe the same capability under different conditions. Compare like-for-like variants, check the unit and test condition where available, and use a head-to-head page to see whether a measurable difference is material for your own use.
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