The primary purpose of an in-body image stabilisation (IBIS) system is to compensate for the accidental movements that occur when photographers are handholding a camera and therefore enable sharp images to be captured when using slower shutter speeds than normal. It works by detecting the camera-shake and shifting the sensor by tiny amounts to correct for it so that the image isn’t blurred.
The fact that the sensor can be moved very precisely enables another feature, usually called something like Pixel Shift Multi Shot mode or High Res Shot mode, that is now found in some cameras from Fujifilm, Olympus / OM System, Panasonic, Pentax and Sony. When the mode is activated, the camera takes a series of images, shifting the sensor by a tiny amount, sometimes half the width of a pixel, between each one. These images can then be combined into one image to either create a larger image with more detail, or in the early incarnations in Sony and Pentax cameras, images that have the same pixel
