What is "aperture priority"

alt. (context photography often used attributively English) A setting in many professional-grade and advanced-amateur-grade cameras which allows a photographer to manually set the aperture setting of an exposure while the camera then automatically selects the correct shutter speed for that exposure. n. (context photography often used attributively English) A setting in many professional-grade and advanced-amateur-grade cameras which allows a photographer to manually set the aperture setting of an exposure while the camera then automatically selects the correct shutter speed for that exposure.

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 set a specific aperture value ( f-number) while the camera selects a shutter speed to match it that will result in proper exposure based on the lighting conditions as measured by the camera's light meter. 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 an appropriate aperture, or program mode where the camera selects both.