SLR lenses mount onto the camera body.
SLR (Single Lens Reflex) cameras feature interchangeable lenses, which permits the photographer to choose the lens most appropriate to the scene he is shooting. However, not every SLR camera can use any SLR lens on the market; instead, the photographer must ensure the lens he is purchasing matches the lens mount of his camera. Even if the lens and camera are made by the same manufacturer, the mount on the lens and the mount on the camera body may not match.
Canon
Canon has two types of lens mounts: EF and EF-S. EF stands for Electro-Focus, and the S in the second type of lens stands for Short back focus. Full-frame Canon cameras can only use EF lenses, while smaller Canon cameras can use both EF and EF-S lenses. The EF-S lens features a more protruding back element, which will interfere with the movement of the mirror inside the camera body, which can cause damage to the lens and the mirror.
Pentax
The Pentax mount is also called the M42 screw mount and is a universal screw mount that fits on almost any SLR body. This is because while other mounts include electronic components that must interface with the SLR body, the M42 screw mount lenses have their aperture and focus controlled by rings on the lens itself. While some of the automatic features of modern SLRs will not work (such as autofocus and autoexposure), this type of lens will fit on almost all lens mounts. The M42 is so named because the threads are 42 inches in diameter, which is the standard size for many cameras.
Nikon
The newer Nikon AIS lens mounts are intended for use with newer Nikon cameras (those featuring automatic controls with focus and exposure). All lenses and cameras manufactured by Nikon after 1977 use this type of lens mount; however, lenses produced before 1977 can be mounted on newer cameras as long as an adapter is used.
Olympus
Since the first manufactured Olympus lens, there has been only a single Olympus lens mount: the OM. Every OM lens fits every OM camera, which is unlike other manufacturers who have changed their lens mounts with new technology or who concurrently manufacture two different types of mounts. Olympus mounts feature electronic connections for newer cameras with autofocus and autoexposure capabilities, but older lenses without these contacts can function in the same way albeit with manual controls.
Tags: lens mount, lens mounts, camera body, screw mount, type lens
