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

Canon EF vs. Nikon Z

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

Comparing:
Canon EF
Nikon Z

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 Z Mount (introduced in 2018 for the Z-series mirrorless system) features the shortest Flange Focal Distance (16.0 mm) and the widest inner throat diameter (55.0 mm) among current major full-frame mirrorless mounts (Sony E, Canon RF, Leica L). This geometry enables extreme optical designs, including the ultra-fast NIKKOR Z 58mm f/0.95 S Noct.

View full Nikon Z spec sheet →

Specification Comparison Table

9 Parameters
Parameter / Spec
Flange Focal Distance (FFD)
44.00 mm (1.732 in) 16.00 mm (0.630 in — the shortest FFD among current major full-frame mirrorless mounts)
Inner Throat Diameter
54.00 mm (2.126 in) 55.00 mm (2.165 in — the largest throat diameter among current major full-frame mirrorless mounts)
Bayonet Tabs
3 locking tabs with clockwise twist 4 asymmetrical locking tabs with counter-clockwise twist (traditional Nikon direction)
Electronic Interface
8 gold-plated electronic contacts (expanded to 11 pins on EF super-telephoto lenses for teleconverters) 11 gold-plated contact pins
Camera Systems
Canon EOS-1D X Mark III, EOS 5D Mark IV, EOS 6D II, EOS Rebel series, Cinema EOS C300/C500 Nikon Z9, Z8, Z7 II, Z6 III, Zf (full frame), Z50, Zfc, Z30 (DX APS-C)
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)
Max Theoretical Aperture
Mount geometry (throat diameter and FFD) permits faster designs than F-mount allowed; the fastest lens actually shipped is the Z 58mm f/0.95 S Noct -- claims of a precise theoretical f/0.58 limit are back-of-envelope extrapolations, not a published Nikon figure
Legacy F-Mount Adaptability
Nikon FTZ / FTZ II adapter (30.5 mm spacer) provides full AF/AE with AF-S and AF-P NIKKOR lenses