A mode dial or camera dial is a dial used on digital cameras to change the camera's mode. Most digital cameras, including dSLR and SLR-like cameras, support modes, selectable either by a dial or from a menu. On point-and-shoot cameras which support modes a range of scene types is offered. On dSLR cameras and SLR-like cameras, mode dials usually offer access to manual settings. The more compact point-and-shoot cameras, and cameras offering a great many modes, do not have mode dials, using menus instead. Some SLR lenses themselves offer control over things such as aperture, reducing the need for mode support in the camera body.
Location of the dial
On most dSLRs and SLR-like bridge cameras, the mode dial is located at the top of the camera, to one side of the flash/viewfinder hump. On point-and-shoot cameras, however, the mode dial's location is less standard. On many models, it is found on top like dSLRs. On other point-and-shoots, particularly those with a thin body, the dial is found on the back of the camera, often coupled with a menu-navigation button. Some thin cameras use a slide switch rather than a dial.
Modes
Various camera types and specific cameras have different modes. The simpler dial in the top illustration has:
Automatic modes: Auto, Action, Portrait, Night portrait, Landscape, Macro.
Most dSLRs have a few manual settings and a small sample of automatic modes. Most SLR-like cameras have manual modes and several automatic scene modes. On point-and-shoot cameras, all manual control may be condensed into one mode or may be completely absent. Many compact cameras show a large array of scene modes. Point-and-shoot and SLR-like digital cameras usually have a movie mode to capture videos, and many modern dSLRs also support movie modes. Detailed information found by users on the modes supported by digital cameras are to be found in the ongoing list of digital camera modes.
A or Av: Aperture priority AKA "Aperture value" allows the photographer to control the aperture, while the shutter speed and ISO sensitivity are calculated by the camera.
S or Tv: Shutter priority AKA "Time value" allows the photographer to control the shutter speed, while the aperture and ISO sensitivity are calculated by the camera.
Sv: Sensitivity value allows the photographer to control the ISO sensitivity, while aperture and shutter speed are calculated by the camera
M: Manual mode allows the photographer to control shutter speed, aperture and ISO independently.
In automatic modes the camera determines all aspects of exposure, choosing exposure parameters according to the application within the constraints of correct exposure, including exposure, aperture, focussing, light metering, white balance, and equivalent sensitivity. For example in portrait mode the camera would use a wider aperture to render the backgroundout of focus, and would seek out and focus on a human face rather than other image content. In the same light conditions a smaller aperture would be used for a landscape, and recognition of faces would not be enabled for focussing. Some cameras have tens of modes, showing the majority only in the menu rather than on the dial. Many cameras do not document exactly what their many modes do; for full mastery of the camera one must experiment with them. In general:
Action or sport mode increases ISO and uses a fast shutter speed to capture action.
