Image sensors are available in many shapes and sizes, and with different capabilities. But in this post, we will focus on one very important thing: the electronic shutter methods that are available.
Most consumer cameras use a rolling shutter method. With this method, the pixels on the sensor are read sequentially. When you press the shutter button, the camera scans through all the pixels and stores the information digitally. This means that the first pixel will be read out at a different time than the last pixel. And everything that happens after the first pixel is read out will still be captured by the last pixel, and the pixels in between.
Global-shutter sensors read out all pixels of the sensor simultaneously, so the entire frame represents image data that was captured at the same moment in time. This method is not subject to the same motion artifacts as the rolling-shutter method.
In everyday use, you won't notice if your camera uses the rolling shutter method. Only when you're capturing an image of a fast-moving object (like a fan), you may notice some motion artifacts like deformed fan blades.
In situations that require high-performance imaging, rolling shutter can severely affect your data. In such cases, it is better to use a global-shutter sensor, to ensure that your image represents the same instant in time and to prevent rolling shutter artifacts.