When auto or aperture priority automatic exposure is referred to in automatic cameras, in which the aperture is manually selected; the camera then adjusts the exposure metering as determined by the appropriate exposure time automatically. Cameras that are equipped with an automatic timer to be also referred to as a time point. On the mode dial of most cameras, this mode is A ( engl. aperture priority ) or Av ( aperture value engl. ) marked.
The bezel is a photographic design elements, such as the depth of field can be controlled with the important properties of the image. An automatic timer is used when the photographer example, in a portrait deliberately have no sharpness or blur the image background by a possible opening the aperture ( ie small f-number, eg f1, 4 or f2, 0) reach wants or in landscape photography when the largest possible depth of field is desired by the smallest possible aperture (ie large f number, eg f16 or f22 ).
Most modern SLR cameras have an aperture priority mode ( Aperture Priority); on compact cameras usually only high-order models have this feature.