Nikon F Mount: lens mount with 44mm diameter and 46.5mm flange distance. Largely backward-compatible since 1959.
Technical Details
The F Mount features a bayonet diameter of 44mm with a flange focal distance of exactly 46.5mm. Electrical communication is handled by up to ten contact pins, gradually introduced from 1977 onwards. The system supports manual and automatic aperture control via the mechanical aperture follower and electronic signals. Modern F Mount lenses utilize AF-S (Silent Wave Motor) or AF-P (Stepping Motor) drives. The mount is backward compatible, with AI lenses (since 1977) offering full functionality.
History & Development
In 1959, Nikon introduced the F Mount with the legendary Nikon F, named after its three characteristic bayonet "wings." In 1977, the AI modification (Automatic Indexing) was implemented for automatic aperture transmission. 1986 saw the addition of AF lenses with electronic focusing. The G series (1996) eliminated the manual aperture ring in favor of purely electronic control. In 2018, Nikon complemented the F Mount system with the mirrorless Z Mount system, while the F Mount continues to be produced.
Practical Use in Film
F Mount lenses are frequently used on digital cinema cameras like RED or ARRI ALEXA via adapters. The Nikkor 14-24mm f/2.8, 24-70mm f/2.8, and 70-200mm f/2.8 optics are standard tools for documentaries and independent productions. Cinematographers appreciate the smooth aperture rings and precise focusing of manual AI-S lenses from the 1980s. The use of adapters allows the extensive F Mount lens inventory to be utilized on cinema cameras, though without electronic aperture control on G lenses.
Comparison & Alternatives
Canon EF Mount (54mm diameter, 44mm flange focal distance) offers a larger opening for faster lenses, while the F Mount is mechanically more stable due to its longer flange focal distance. Sony E Mount (mirrorless, 18mm flange focal distance) allows for a more compact design but loses direct optical viewfinder compatibility. PL Mount dominates professional cinema lenses with its more robust connection and standardized gears. The F Mount is particularly suitable for hybrid photo-film productions and for budget-conscious projects with an existing Nikkor lens collection.