The aperture is basically a hole in the camera’s lens that lets light pass through it to 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 and ultimately the film or censor.
The aperture not only influences picture brightness but also regulates depth of focus. Most cameras are equipped with an iris aperture that can be freely adjusted or set according to pre-selected values.