In this article, we look at the Sensor-shift image-stabilisation system, providing a guide to what it is for, and how it works
Perhaps the biggest enemy of any photographer holding a camera is camera shake. The Sensor-shift image-stabilisation system is one of three automated in-camera solutions developed to reduce or eliminate the effects of camera shake when using longish exposures. The two others are optical image stabilisation (OIS) and electronic or digital image stabilisation. The Sensor-shift image-stabilisation system is arguably the best of the three and here is why.
The Sensor-shift image-stabilisation system works by moving the camera’s sensor around the image plane using electrical actuators. If any shake motion is detected by the camera’s accelerometers, it calculates in real time the direction and speed to move the sensor, so that it remains stationary in relation to the image being projected onto it by the lens. There is a limit to its effectiveness, just like any image-stabilisation system, but it can be useful in moderately low-light situations when a tripod or other support is unavailable.
The advantages over the other systems are that the sensor-shift image-stabilisation system works with any lens attached to the camera (so long as the camera knows the focal length of the lens), not just lenses fitted with optical image stabilisation, and there is minimal compromise of optical image quality. The latest sensor-shift image-stabilisation systems can now work in up to five axes to correct camera movement up and down, left and right, and camera rotation.
The Sensor-shift image-stabilisation system is found in Olympus and Pentax cameras, as well as some Sony and Panasonic models. Pentax uses it for some neat features on some of its cameras, such as the ability to move the sensor during very long exposures in order to keep stars sharp as they move across the night sky. Olympus uses one on the OM-D E-M5 Mark II to make 40MP high-resolution composite images, too.