Collection: SLR Lenses

On most SLR and DSLR cameras, the lens can be changed. This enables the use of lenses that are best suited for a given photographic need, and allows for the attachment of specialized lenses. Film SLR cameras have existed since the late 1950s, and over the years, a very large number of different lenses have been produced, both by camera manufacturers (who typically only make lenses intended for their own camera bodies) and by third-party optics companies who may make lenses for several different camera lines.

DSLRs became affordable around the mid-1990s, and have become extremely popular in recent years.^[when?] Some manufacturers, such as Minolta, Canon and Nikon, chose to make their DSLRs 100% compatible with their existing SLR lenses from the beginning, allowing owners of new DSLRs to continue to use their existing lenses and get a longer lifespan from their investment. Others, for example Olympus, opted for new lens mounts and series of lenses for their DSLRs. Modern Pentax DSLRs like the K-3 and K-50 are backwards-compatible with K-mount SLR lenses, though features that are included in newer lenses (e.g. autofocus) may not work. There are a few exceptions; the MZ and ZX series of Pentax film cameras do not work with some older lenses.

As implied by the above, lenses are only directly interchangeable within the mount system for which they are built. Mixing mounting systems requires an adapter, which most often results in compromises such as loss of functionality (e.g. lack of autofocus or automatic aperture control). Furthermore, the adapter may require an additional optical element to correct for varied registration distances (the distance from the rear of the mount to the focal plane on the image sensor or film). Adapters may not be available to bridge every combination of lens mount and camera mount.