Aperture Priority

Aperture priority, often abbreviated A or Av (for Aperture value) on a camera mode dial, is a setting on some cameras that allows the user to choose a specific aperture value while the camera selects a shutter speed to match. The camera will ensure proper exposure. This is different from manual mode, where the user must decide both values, shutter priority where the user picks a shutter speed with the camera selecting the aperture to match, or program mode where the camera selects both.

The main purpose of using aperture-priority mode is to control the depth of field. Aperture priority is useful in landscape photography, where a narrow aperture is necessary if objects in foreground, middle distance, and background are all to be rendered crisply, while shutter speed is often immaterial. It also finds use in portrait photography, where a wide aperture is desired to throw the background out of focus and make it less distracting.

Another common use of aperture priority mode is to suggest how the camera should determine a shutter speed, without risking a poor exposure. In landscape photography a user would select a small aperture when photographing a waterfall, hoping to allow the water to blur through the frame. When shooting a portrait in dim lighting, the photographer might choose to open the lens to its maximum aperture in hopes of getting enough light for a good exposure.

In addition, aperture priority mode allows the photographer to force the camera to operate the lens at its optimum apertures within its aperture range for a given focal length of the lens. Commonly, lenses provide greatest resolving power with relatively medium-sized apertures.

Other articles related to "aperture, aperture priority, priority":

Canon AV-1
... in the United States, had clamored for such a camera because competing brands offered mostly aperture-priority cameras and some preferred it ... The AV in the name referred to the type of autoexposure Av (Aperture Value) is a common abbreviation for aperture priority ...
Yashica/Kyocera-built Contax Models - 35 Mm SLR Models
... and electronically controlled shutter 139 Q 1979 aperture priority, TTL and TTL flash metering, X-synch 1/100 137 MD 1980 aperture priority, motor film transport (2-3 frame/s) RTS II ...
Shutter Priority
... Shutter priority refers to a setting on some cameras that allows the user to choose a specific shutter speed while the camera adjusts the aperture to ensure correct exposure ... This is different from manual mode, where the user must decide both values, aperture priority where the user picks an aperture with the camera selecting the ... Shutter priority with longer exposures is chosen to create an impression of motion ...
Canon T90 - Exposure
... Variable Shift Program AE allows the photographer to bias the camera towards narrow aperture with three Wide Angle settings, or fast shutter speed with three Telephoto settings as well as the standard mode ... For more manual control, Aperture Priority AE and Shutter-Speed Priority AE allow the photographer to set one exposure variable manually while the camera chooses the other ... For example, in Aperture Priority mode, if the photographer has the aperture fixed wide open to photograph a very bright scene, the correct shutter speed to expose correctly at that aperture ...

Famous quotes containing the words priority and/or aperture:

    It can be fairly argued that the highest priority for mankind is to save itself from extinction. However, it can also be argued that a society that neglects its children and robs them of their human potential can extinguish itself without an external enemy.
    Selma Fraiberg (20th century)

    Animals used to provide a lowlife way to kill and get away with it, as they do still, but, more intriguingly, for some people they are an aperture through which wounds drain. The scapegoat of olden times, driven off for the bystanders’ sins, has become a tender thing, a running injury. There, running away ... is me: hurt it and you are hurting me.
    Edward Hoagland (b. 1932)