SLR Bodies
The bodies of SLR cameras sport a number of features. Here are some you can expect to find on both digital and film SLRs:
Accessory shoe. A small bracket on top of the camera used for mounting a flash unit.
Shutter release button. Usually located on the right side of the camera — either on the front or on the top — as it's facing away from you.
Command dial. For controlling automatic features and shooting modes.
Lens release button. For using multiple lenses, in succession, on the same camera.
Cable release connection. Used to fire the shutter from a distance to prevent vibrations during long exposures.
Tripod socket. Used to attach the camera to the tripod.
Power switch.
Self-timer button.
Viewfinder.
Built-in flash.
Film cartridge information window. Found in film cameras only.
LCD panel. Displays shooting information, including number of exposures taken, shooting mode, shutter speed, exposure, focus mode, and other information.
One feature you'll find on the front of SLR cameras is the lens mount. As the term suggests, this is the place where the lenses attach to the camera. Most SLRs available today are equipped with bayonet mounts, which couple the lens and the camera together with just a quick turn. Other types of mounts, primarily on older film SLRs, include screw mounts and breech-lock mounts, in which a ring on the lens secures it to the camera. Some older lenses with screw mounts can be adapted for use on cameras with bayonet mounts.
On cameras with autofocus capability, you'll see a set of small pins just inside the lens mount. These are electronic contacts, which transmit data back and forth from the camera to the lens, controlling such things as auto-focus and aperture settings. Look on the back of an autofocus lens, and you'll see a series of flat contact points that match precisely with the electronic contacts inside the lens mount when the lens and camera are correctly joined.
