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

Leica L-Mount vs. Sony E-Mount

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

Comparing:
Leica L-Mount
Sony E-Mount

The Leica L-Mount (developed by Leica Camera in 2014 and formalized under the L-Mount Alliance with Panasonic, Sigma, DJI, and Leitz Cine in 2018) is a 4-tab bayonet mount featuring a 20.0 mm Flange Focal Distance, a 51.6 mm throat diameter, and a robust stainless steel clamping mechanism covering both full frame and APS-C formats.

View full Leica L-Mount spec sheet →

The Sony E-Mount (introduced in 2010 for NEX mirrorless and expanded in 2013 to 35mm full frame as FE) is a 3-tab bayonet lens mount featuring a 18.0 mm Flange Focal Distance (FFD), a 46.1 mm throat diameter, and a 10-pin high-speed electronic interface. It is the most widely adopted open third-party full-frame mirrorless mount in the photographic industry.

View full Sony E-Mount spec sheet →

Specification Comparison Table

9 Parameters
Parameter / Spec
Flange Focal Distance (FFD)
20.00 mm (0.787 in) 18.00 mm (0.709 in — distance from lens mount mating surface to sensor plane)
Inner Throat Diameter
51.60 mm (2.031 in) 46.1 mm (1.815 in)
Bayonet Tabs
4 asymmetrical stainless steel locking tabs (high mechanical rigidity for cinema primes) 3 asymmetrical locking tabs with clockwise twist lock
Electronic Interface
8 gold-plated electronic spring contacts (standardized cross-manufacturer protocol) 10 gold-plated leaf contact pins (supports real-time eye-AF tracking, OSS, active lens breathing compensation)
Camera Systems
Panasonic Lumix S5 II / S5 IIX / S1H / BS1H, Leica SL2 / SL3 / Q series, Sigma fp / fp L, DJI Ronin 4D Sony A7 / A9 / A1 series, FX3 / FX6 cinema lines, A6000-series APS-C bodies
Alliance Partners
Leica Camera AG, Panasonic Corporation, Sigma Corporation, DJI, Ernst Leitz Wetzlar GmbH, Blackmagic Design
Coverage Formats
SL (35mm Full Frame 36×24 mm) and TL (APS-C 23.6×15.7 mm)
Full-Frame vs APS-C
FE lenses cover 36×24 mm full frame; E lenses cover APS-C (auto-crops on full-frame bodies)
Third-Party Protocol License
Open disclosure to lens manufacturers (Sigma, Tamron, Zeiss, Samyang, Voigtländer)