Digital camera modes in the context of DSLR

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 mirrorless cameras, support modes, selectable either by a rotary dial or from a menu. On point-and-shoot cameras which support modes a range of scene types is offered. On dSLR and mirrorless 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 interchangeable lenses themselves offer control over things such as aperture, reducing the need for mode support in the camera body.

The Bulb setting (abbreviated B) on camera shutters is a momentary-action mode that holds shutters open for as long as a photographer depresses the shutter-release button. The Bulb setting is distinct from shutter's Time (T) setting, which is an alternate-action mode where the shutter opens when the shutter-release button is pressed and released once, and closes when the button is actuated again.