Why Does the Shutter “Roll”?
Rolling vs Global Shutter in sCMOS Cameras — quick guide for engineers and buyers.
In high-end cameras, beyond pixel count, frame rate, and sensitivity, there’s one crucial detail that often gets overlooked — the shutter mode. In sCMOS cameras the two most common types are Rolling Shutter and Global Shutter.
Rolling Shutter
Imagine turning on the lights in a skyscraper one floor at a time. Each row of pixels begins exposure sequentially rather than simultaneously. This creates a small timing offset between rows which can cause distortion with fast motion.
Global Shutter
Imagine flipping one master switch — all lights on at once. All pixels start and end exposure at the exact same moment, capturing a true snapshot. The result: synchronized, distortion-free images even with motion.
Pros & Cons
| Feature | Rolling Shutter | Global Shutter |
|---|---|---|
| Noise | Lower | Higher (slightly) |
| Distortion with motion | Possible | None |
| Synchronization | More complex | Easier |
| Max Frame Rate | Higher | Lower |
| Best For | Slow/static scenes, low-noise imaging | High-speed, synchronized imaging |
Real-world Example
Photograph a spinning fan: with Rolling Shutter blades may look bent or skewed; with Global Shutter blades remain straight and crisp — no distortion, no time lag.
How to Choose
- Check object speed: Fast → Global. Slow/static → Rolling.
- Sync needs: Need strobes/lasers/multi-camera sync? → Global.
- Noise & frame rate: Want lowest noise & highest FPS? → Rolling.
- Dual-mode cameras: Many premium sCMOS models let you switch between modes.
Rapixel Tech Recommendations
At Rapixel Tech we help customers choose the right sensor and camera for their application. When publishing product pages, always include a clear field for Shutter Type: Rolling / Global / Switchable and present sample comparison images for motion-critical applications.
Need help choosing?
Not sure which shutter mode suits your project? Contact our sales engineers for a tailored recommendation.
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