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

Canon EF vs. Nikon F

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

Comparing:
Canon EF
Nikon F

The Canon EF Mount (introduced in 1987 for the EOS autofocus SLR system) revolutionized photographic camera design as the first 100% all-electronic lens mount, eliminating all mechanical aperture linkages and autofocus drive shafts. Featuring a 44.0 mm Flange Focal Distance and a large 54.0 mm throat diameter, over 150 million EF lenses were manufactured over 33 years.

View full Canon EF 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)
44.00 mm (1.732 in) 46.50 mm (1.831 in — longest FFD among major 35mm SLR mounts)
Inner Throat Diameter
54.00 mm (2.126 in) 44.00 mm (1.732 in)
Bayonet Tabs
3 locking tabs with clockwise twist 3 locking tabs with counter-clockwise twist (opposite of Canon/Sony)
Camera Systems
Canon EOS-1D X Mark III, EOS 5D Mark IV, EOS 6D II, EOS Rebel series, Cinema EOS C300/C500 Nikon F, F3, FM2, F5 (film), Nikon D850, D780, D6, D7500, D500 (digital DSLRs)
Electronic Interface
8 gold-plated electronic contacts (expanded to 11 pins on EF super-telephoto lenses for teleconverters)
Internal Actuators
Internal USM (Ultrasonic Motor) in lens body + internal electromagnetic aperture diaphragm (EMD)
Variants
EF (Full Frame), EF-S (APS-C with rubber bumper back-focus extension), EF-M (discontinued APS-C mirrorless)
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)