A leaf 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 comprises a small number of identical overlapping metal blades, called leaves, that open and close in order to expose a photograph. It is usually situated close to the iris within the camera lens. Depending on the way the 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 is arranged it is referred to as ‘between-lens’ or ‘behind the lens’. Common leaf shutters include the German Compur and Prontor, and the Japanese Copal, Citizen and Seikosha.