# item.guide
Side-by-Side Comparison Lens Mounts

Canon RF vs. Nikon F

Comparing 2 standards across 9 specifications. 9 key differences identified.

Comparing:
Canon RF
Nikon F

The Canon RF Mount (introduced in 2018 for the EOS R system) is a 3-tab full-frame mirrorless bayonet mount featuring a 20.0 mm Flange Focal Distance, a wide 54.0 mm inner throat diameter, and an advanced 12-pin high-speed data bus. Retaining the large 54mm diameter of the classical EF mount, it enables ultra-fast aperture lenses such as the RF 28-70mm f/2L and 50mm f/1.2L.

View full Canon RF spec sheet →

The Nikon F-Mount (introduced in 1959 with the legendary Nikon F SLR) is one of the most storied lens mounts in photographic history, maintaining a continuous 46.5 mm Flange Focal Distance and 44.0 mm throat diameter for over 60 years. Spanning non-AI manual lenses to modern electronic-diaphragm AF-S/AF-E glass, over 100 million F-mount lenses were produced.

View full Nikon F spec sheet →

Specification Comparison Table

9 Parameters
Parameter / Spec
Flange Focal Distance (FFD)
20.00 mm (0.787 in) 46.50 mm (1.831 in — longest FFD among major 35mm SLR mounts)
Inner Throat Diameter
54.00 mm (2.126 in — identical to legacy Canon EF mount) 44.00 mm (1.732 in)
Bayonet Tabs
3 asymmetrical stainless steel bayonet tabs with clockwise mounting twist 3 locking tabs with counter-clockwise twist (opposite of Canon/Sony)
Camera Systems
Canon EOS R5 / R6 / R3 / R8 / R, Cinema EOS C70 / C80 / C400, APS-C EOS R7 / R10 Nikon F, F3, FM2, F5 (film), Nikon D850, D780, D6, D7500, D500 (digital DSLRs)
Electronic Interface
12 contact pins (high-bandwidth bidirectional bus for lens control ring and Coordinated IS up to 8 stops)
Legacy Adaptability
100% native AF/IS compatibility with all Canon EF/EF-S lenses via Canon EF-EOS R adapter (24mm spacer)
Lens Control Ring
Physical programmable control ring on all native RF lenses (aperture, ISO, exposure compensation)
Historical Generations
Non-AI (1959) -> AI (1977) -> AI-S (1981) -> AF screw-drive (1986) -> AF-D (1992) -> AF-S Silent Wave (1998) -> AF-E Electronic diaphragm (2010s)
Aperture Control History
Spring-loaded mechanical stop-down lever (moved to electromagnetic diaphragm in 'E' lenses)