Nikon F-mount

The Nikon F-mount is a type of interchangeable lens mount developed by Nikon for its 35 mm Single-lens reflex cameras. The F-mount was first introduced on the Nikon F camera in 1959, and features a three lug bayonet mount with a 44 mm throat and a flange to focal plane distance of 46.5 mm. The company continues to use variations of the same lens mount specification for its film and digital SLR cameras.

The Nikon F-mount is one of only two SLR lens mounts (the other being the Pentax K-mount) which were not abandoned by their associated manufacturer upon the introduction of autofocus, but rather extended to meet new requirements related to metering, autofocus, and aperture control. The large variety of F-mount compatible lenses makes it the largest system of interchangeable flange-mount photographic lenses in history. Over 400 different Nikkor lenses are compatible with the system. The F-mount is also popular in scientific and industrial applications, most notably machine vision.

In addition to Nikon's own range of "Nikkor" lenses, brands of F-mount photographic lenses include Zeiss, Voigtländer, Schneider, Angénieux, Samyang, Sigma, Tokina, Tamron, Hartblei, Kiev-Arsenal, Lensbaby, and Vivitar. F-mount photographic cameras include current models from Nikon, Fujifilm, Sinar, Kenko and Horseman. Numerous other manufacturers employ the F-mount in non-photographic imaging applications.

The F-mount has a significant degree of both backward and forward compatibility. Many current autofocus F-mount lenses can be used on the original Nikon F, and the earliest manual-focus F-mount lenses of the 1960s and early 1970s can, with some modification, still be used to their fullest on all professional-class Nikon cameras. Incompatibilities do exist, however, and adventurous F-mount users should consult product documentation in order to avoid problems. For example, many electronic camera bodies cannot meter without a CPU enabled lens, the aperture of G designated lenses cannot be controlled without an electronic camera body, and non-AI lenses (manufactured prior to 1977) can cause mechanical damage to later model bodies unless they are modified to meet the AI specification. Many manual focus lenses can be converted to allow metering with consumer Nikon bodies by adding a Dandelion chip to the lens.

Most Nikon F-mount lenses cover the standard 36×24 mm area of 135 film and the Nikon FX format, while DX designated lenses cover the 24×16 mm area of the Nikon DX format, and industrial F-mount lenses have varying coverage. DX lenses may produce vignetting when used on film and FX cameras. However, Nikon lenses designed for film cameras will work on Nikon digital system cameras with the limitations noted above.

Unlike most other lens mounts, F-mount lenses lock by turning counter-clockwise (when looking at the front of lens) and unlock clockwise. Likewise, nearly all F-mount lenses have focus and aperture controls which operate in the reverse direction from the norm. From the perspective of the operator behind the camera, the focus ring turns clockwise towards infinity, and the aperture ring turns clockwise to close.

Originally all Nikon bodies and lenses were manufactured in Japan. Since 1991, however, increasing amounts of high-volume production (mostly consumer bodies and lenses) have been shifted to production centers in Thailand and China.