Lenses for SLR and DSLR cameras

There are a few exceptions; the MZ and ZX series of Pentax film cameras do not work with some older lenses.

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).

[3] The focal length of a lens, together with the size of the image sensor or film in the camera, determines the angle of view.

However, this specification is insufficient to compare lenses for different cameras, because field of view also depends on sensor size.

For example, a 35 mm lens mounted on a full-frame Canon EOS 5D provides a slightly wide-angle view, while the same lens mounted on an APS-C Canon EOS 400D provides a "normal" or slightly telephoto view.

This is different from the late 1980s when, due to image quality concerns, most professional photographers still relied primarily on standard non-zoom lenses.

"Super-zoom" lenses with a range of 10× or even 14× are becoming more common, although the image quality does typically suffer a bit compared with the more traditional zooms.

(The M42 lens mount should not be confused with the T-mount, which shares the 42mm throat diameter, but differs by having a 0.75mm thread pitch.)

As noted above under focal length, Canon makes DSLRs with various sensor sizes, and all using the EF or EF-S lens mounts.

This leads to the interesting phenomenon of the same EF lens providing different angles of view depending on which camera it is mounted on.

Third-party lenses compatible with Canon's EF and EF-S mounts are manufactured by Sigma, Tamron, Tokina and Zeiss.

Currently Olympus, Leica (in cooperation with Panasonic), and Sigma are making lenses under Four Thirds System consortium licensing.

This leads to both advantages (theoretically smaller, lighter and cheaper lenses and camera bodies) and disadvantages (slightly lower image quality, especially in low-light situations).

Because the lack of a mirror, optical viewfinder, and a shorter flange-focal distance these lenses can be more compact than those for standard Four Thirds.

In North America, Minolta began using the name 'Maxxum' for the SLR autofocus cameras, lenses and flashes while in Europe they were called 'AF' (first series) and 'Dynax' (second and later generations), and in Asia the 'α' (Alpha) branding was used, though they were otherwise identical in appearance and function - all of the equipment is 100% interchangeable regardless which of the names it carries.

Most Minolta A-mount compatible lenses, whether built by Minolta or one of the aftermarket lens manufacturers, are focused externally by a shaft connecting the autofocus computer and motor inside the camera body that mechanically connects to the internal focusing gears inside of the lens body.

Keeping the autofocus motors inside the camera body and as far away from the lens glass as possible, reduces vibration, an additional benefit.

This highly reliable shaft-driven autofocus system was extremely successful but is not seen in modern lenses.

The company has since abandoned traditional SLR design, and now uses the "α" brand name for its current line of SLT and ILCA cameras with fixed semi-reflective mirrors and electronic viewfinders, as well as its current line of E-mount mirrorless cameras.

The Minolta A-mount was retained from the old cameras and was originally named the "Sony α mount system".

Some of the newest A-mount lenses are designated "DT" for Digital Technology; these are for digital cameras with APS-C sensors, and will result in vignetting if used on a film SLR or a full frame DSLR or full frame SLT camera.

Third-party lenses for the AF lens mount are made by Zeiss, Sigma, Tamron, Tokina and Vivitar.

Most Nikon F-mount lenses cover the standard 36×24 mm area of 135 film, while "DX" designated lenses cover the 24×16 mm area of the Nikon DX format DSLR sensors, commonly referred to as APS-C format.

There are basically three types of F mount Nikon lens: Industrial F-mount lenses have varying, often small, film/sensor coverage.

Similarly, some AF-I & AF-S lenses will not work on some older Nikon AF film SLRs.

The only aspects of these manufacturers' lenses that have changed are the addition of electronic contacts, autofocus abilities and, in some cases, the elimination of the external aperture ring for electronic control (i.e., Nikon's 'G-type' auto-Nikkors, which cannot be used on a mechanical SLR camera body).

However, due to the size of the Four Thirds mount it is possible to fit legacy SLR lenses from any manufacturer using an adapter, albeit with manual aperture and focus control.

Minolta (Sony after 2006) phased out its bayonet-mount MC and MD Rokkor lenses for a modified bayonet mount (supporting autofocus) in 1985.

The autofocus sensor(s) and electronics are actually in the camera body, and this circuitry provides electrical power and signals to a motor inside the lens that adjusts the focus.

Users of image-stabilized lenses on bodies with sensor-shift IS should determine which system offers superior performance and turn the other off.