Advanced photo cameras, especially DSLR cameras, offer a variety of Exposure Modes to the photographer. They are also called shooting modes and can fall into one of the following three categories:
- auto
- scene
- P, S, A, & M
When using the auto Exposure Mode, the camera takes full control of shutter speed (LINK) and aperture. It adjusts these setting according to the overall light conditions at the time the photo is taken.
Scene modes also leave the settings to the camera, however, they provide shooting mode presets to the photographer. These “scenes” are optimized for their named purpose, such as portrait, night, sports, nature photography and such.
The Exposure Modes of the last category allow the photographer to set the aperture and/or shutter speed themselves to some degree, depending on which mode is chosen. Consider the following summary:
- P: programmed, aperture and shutter speed are set by the camera
- S: shutter-priority, aperture is set by the camera, shutter speed is set by the photographer
- A: aperture-priority, aperture is set by the photographer, shutter speed is set by the camera
- M: manual, aperture and shutter speed are set by the photographer
Thus, the M Exposure Mode gives the photographer the most freedom over the camera settings.