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

Fujifilm X-Mount vs. Nikon F

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

Comparing:
Fujifilm X-Mount
Nikon F

The Fujifilm X-Mount (introduced in 2012 for the X-Pro1) is a dedicated APS-C mirrorless bayonet mount featuring a 17.7 mm Flange Focal Distance, a 40.7 mm throat diameter, and a 10-pin electronic interface. Designed exclusively for APS-C image circles, it allows compact lens designs optimized for Fujifilm's proprietary X-Trans CMOS sensors.

View full Fujifilm X-Mount 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)
17.70 mm (0.697 in) 46.50 mm (1.831 in — longest FFD among major 35mm SLR mounts)
Inner Throat Diameter
40.70 mm (1.602 in) 44.00 mm (1.732 in)
Bayonet Tabs
3 locking tabs with counter-clockwise mount twist 3 locking tabs with counter-clockwise twist (opposite of Canon/Sony)
Camera Systems
Fujifilm X-T5, X-H2, X-H2S, X-T30 II, X-S20, X-Pro3, X-E4 Nikon F, F3, FM2, F5 (film), Nikon D850, D780, D6, D7500, D500 (digital DSLRs)
Back Focus Distance
Minimum rear optical element clearance of 7.5 mm from sensor
Electronic Interface
10 contact pins (opened to third parties in 2020: Tamron, Sigma, Voigtländer, Viltrox)
Physical Aperture Rings
Standard mechanical aperture rings with 1/3-stop clicks on XF lenses
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)