IBIS, or In-Body Image Stabilisation, is a feature found in some digital cameras that helps to reduce the effects of camera shake when capturing images or videos. It works by using sensors to detect any movement or shake in the camera and then compensates for it by moving the camera’s sensor in the opposite direction of the movement. This results in sharper and clearer images and videos, especially in low light situations, slow shutterEither mechanical and/or electronic shutters are possible. Mechanical systems can use a leaf (or iris) shutter or curtain shutter. In digital cameras a third alternative is also possible: the electronic shutter. This works by activating and then deactivating the CCD so that no further light can be recorded, regardless of whether light is hitting the CCD. The shutter controls the exposure time, which can range from thousandths of a second to several minutes or more. Fast shutter speeds freeze action, slow speeds are more suited to stationary subjects. A tripod is recommended for slow exposure shots to avoid camera shake, or IBIS. More speeds, or when using longer focal lengths.