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

Fujifilm X-Mount vs. Nikon Z

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

Comparing:
Fujifilm X-Mount
Nikon Z

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 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)
17.70 mm (0.697 in) 16.00 mm (0.630 in — the shortest FFD among current major full-frame mirrorless mounts)
Inner Throat Diameter
40.70 mm (1.602 in) 55.00 mm (2.165 in — the largest throat diameter among current major full-frame mirrorless mounts)
Bayonet Tabs
3 locking tabs with counter-clockwise mount twist 4 asymmetrical locking tabs with counter-clockwise twist (traditional Nikon direction)
Electronic Interface
10 contact pins (opened to third parties in 2020: Tamron, Sigma, Voigtländer, Viltrox) 11 gold-plated contact pins
Camera Systems
Fujifilm X-T5, X-H2, X-H2S, X-T30 II, X-S20, X-Pro3, X-E4 Nikon Z9, Z8, Z7 II, Z6 III, Zf (full frame), Z50, Zfc, Z30 (DX APS-C)
Back Focus Distance
Minimum rear optical element clearance of 7.5 mm from sensor
Physical Aperture Rings
Standard mechanical aperture rings with 1/3-stop clicks on XF lenses
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