Rolling shutter is a method of capturing an image where the sensor scans the scene line by line, from top to bottom, rather than all at once. Because each line is exposed at a slightly different moment in time, fast-moving subjects or quick camera movements can produce visible distortions like skewed lines, wobbly footage, or uneven lighting bands. It’s the reason a propeller can look bent in a photo or why handheld phone video sometimes has a jelly-like wobble.
How Rolling Shutter Works
A camera sensor is made up of millions of tiny light-sensitive pixels arranged in rows. With a rolling shutter, the sensor doesn’t expose all those rows simultaneously. Instead, it starts at the top row, records it, then moves to the next row, and so on until it reaches the bottom. Each row begins and ends its exposure at a fractionally different time. The total delay between the first row and the last row is called the readout time, and it’s the root cause of every rolling shutter artifact.
This approach exists because it’s simpler and cheaper to build. Each pixel in a rolling shutter sensor needs only two transistors to move its electrical charge, which means less heat, less noise, and a less complex manufacturing process. That’s why the vast majority of cameras in smartphones, mirrorless cameras, drones, and action cameras use rolling shutter sensors.
Common Rolling Shutter Artifacts
Three distortions show up most often:
- Skew: Vertical lines lean or slant when the camera or subject moves horizontally during the scan. A building might look like it’s tilting, or a passing car appears stretched in one direction. The faster the movement relative to the readout time, the more dramatic the lean.
- Jello effect: When the camera vibrates or shakes, different rows capture slightly different positions of that vibration. The result is a wobbly, jelly-like warping in footage, especially noticeable on straight vertical edges like lampposts or door frames.
- Flash banding: A flash fires for a tiny fraction of a second. If that burst of light happens while the sensor is partway through its scan, only some rows get illuminated. The image ends up with a bright band across part of the frame and normal exposure elsewhere. This also happens under flickering artificial lights like fluorescents or LEDs, which cycle on and off faster than the eye can see.
Electronic Shutters vs. Mechanical Shutters
Rolling shutter is primarily an electronic shutter issue. An electronic shutter works by turning the sensor’s pixel rows on and off digitally, scanning through them in sequence. There are no moving parts, which makes it silent and allows very fast burst shooting, but it leaves the sensor vulnerable to all the artifacts described above.
A mechanical shutter uses physical curtains that slide in front of the sensor. At fast shutter speeds, those curtains form a narrow slit that travels across the sensor, so technically only a strip of the sensor is exposed at any given instant. This is conceptually similar to a rolling shutter, but the curtain moves quickly enough that the time difference between the top and bottom of the frame is much smaller. That shorter delay significantly reduces visible distortion. Many photographers switch to their camera’s mechanical shutter mode when shooting fast action or using flash for exactly this reason.
Global Shutter: The Distortion-Free Alternative
A global shutter exposes every pixel on the sensor at the same instant. The entire frame starts and stops its exposure simultaneously, so there’s zero time difference between the top and bottom of the image. Moving objects look exactly as they did in that single frozen moment, with no skew, no wobble, and no flash banding.
The tradeoff is complexity. A global shutter sensor needs enough onboard memory to store the data from every pixel at once before reading it out, which makes the manufacturing process more involved and the sensor more expensive. For years, global shutters were confined to high-end cinema and industrial machine-vision cameras. They’ve recently started appearing in consumer mirrorless cameras, but they still carry a price premium and can involve tradeoffs in dynamic range or low-light performance compared to rolling shutter sensors at the same price point.
Readout Speed and Stacked Sensors
The severity of rolling shutter depends almost entirely on how fast the sensor can read out all its rows. A slower readout means a bigger time gap between the first and last row, which means more distortion. A faster readout shrinks that gap and makes artifacts harder to notice, even if they’re technically still present.
Modern stacked sensor designs have dramatically improved readout speeds. These sensors place processing circuits and dedicated memory directly beneath the light-collecting layer, creating an extremely short path for data. Entry-level and mid-range mirrorless cameras typically read out in the high single digits to low teens of milliseconds. The Canon EOS R6 III, for example, achieves readout times around 13 milliseconds. Fully stacked professional sensors push into the single-digit millisecond range in their fastest modes, making rolling shutter nearly invisible in most real-world shooting.
For context, a readout time of 5 ms means the bottom of your frame is captured only five thousandths of a second after the top. At that speed, a subject would need to be moving extremely fast for any skew to be perceptible.
How to Reduce Rolling Shutter Distortion
If your camera has a mechanical shutter option, using it is the simplest fix for stills, especially when shooting with flash or photographing fast-moving subjects. For video, where mechanical shutters aren’t used, a few practical techniques help.
Set your shutter speed to roughly twice your frame rate. If you’re shooting at the standard 24 frames per second, that means a shutter speed around 1/50 of a second. This gives you just enough motion blur to mask minor rolling shutter artifacts without making the image look soft. Going much faster than that can actually make distortion more visible because every row captures a sharper, more distinct slice of the motion.
Minimizing camera movement makes a big difference. Use a tripod, gimbal, or stabilizer whenever possible. The jello effect is almost always triggered by handheld vibration, so anything that smooths out your camera’s motion will reduce it. Even bracing the camera against a solid surface helps.
When prevention isn’t enough, post-production software can clean up what’s left. Video editing tools offer rolling shutter repair effects that analyze the distortion pattern and skew the image back into alignment. You can typically adjust the repair intensity and scan direction to match how your specific camera reads out its sensor. The results aren’t always perfect, particularly with severe wobble, but for mild to moderate distortion they’re remarkably effective.
When Rolling Shutter Actually Matters
For most everyday photography and video, rolling shutter is a non-issue. It becomes noticeable in specific situations: shooting spinning propellers or rotors, panning quickly across a scene, recording from a vibrating platform like a car dashboard or helicopter, or using flash with an electronic shutter. If you regularly shoot in these scenarios, prioritizing a camera with a fast sensor readout or a global shutter option will save you frustration. If you mostly shoot portraits, landscapes, or casual video, the rolling shutter on any modern camera is fast enough that you’re unlikely to ever see an artifact.