Definition: Automatic exposure (AE) is an automated digital camera system that sets the aperture and/or shutter speed, based on the external lighting conditions for the photo. With beginner-level digital cameras, photographers usually can select one of three different AE modes.
- Aperture priority allows the photographer to set the aperture value, and the digital camera then determines the shutter speed. This is called a semi-automatic exposure.
- Shutter priority allows the photographer to set the shutter speed, and the digital camera then determines the aperture setting. This also is called a semi-automatic exposure.
- Program mode is a fully automatic mode, where the camera sets shutter speed and aperture. This mode sometimes is called Program AE.
