Aperture

Aperture
Mechanism behind the lens that controls the amount of light entering the camera. 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

Aperture Priority
In this mode, the user can adjust the aperture and the camera automatically selects the best shutter speed to match it. In most cameras, the Aperture Priority mode is denoted by the letter “A”. Shutter Priority.