Nikon Z
Lens Mounts · 7 specs
Direct Answer
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.
Source: Nikon Corporation Z-System Technical Whitepaper / CIPA · Last reviewed Aug 28, 2026
Specs
| Flange Focal Distance (FFD) | 16.00 mm (0.630 in — the shortest FFD among current major full-frame mirrorless mounts) |
| Inner Throat Diameter | 55.00 mm (2.165 in — the largest throat diameter among current major full-frame mirrorless mounts) |
| Bayonet Tabs | 4 asymmetrical locking tabs with counter-clockwise twist (traditional Nikon direction) |
| Electronic Interface | 11 gold-plated contact pins |
| 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 |
| Camera Systems | Nikon Z9, Z8, Z7 II, Z6 III, Zf (full frame), Z50, Zfc, Z30 (DX APS-C) |
The 55mm / 16mm Optical Advantage
Nikon designed the Z-mount with extreme physical dimensions: a 55.0 mm inner diameter (11 mm larger than the historical Nikon F-mount) and an ultra-short 16.0 mm FFD. This allows rear optical elements to sit close to the sensor with huge diameter, eliminating corner ray angle steepness and delivering corner-to-corner edge sharpness wide open at f/1.2 and f/0.95.
Cross-System Adapter Feat
Because Nikon Z has the shortest FFD of all full-frame mounts (16.0 mm vs Sony E 18.0 mm and Leica M 27.8 mm), third-party adapters (like Megadap ETZ) can adapt Sony E-mount autofocus lenses directly onto Nikon Z cameras using an ultra-thin 2.0 mm adapter ring with full AF-C and eye-tracking support.