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

Canon RF vs. Leica L-Mount

Comparing 2 standards across 9 specifications. 8 key differences identified.

Comparing:
Canon RF
Leica L-Mount

The Canon RF Mount (introduced in 2018 for the EOS R system) is a 3-tab full-frame mirrorless bayonet mount featuring a 20.0 mm Flange Focal Distance, a wide 54.0 mm inner throat diameter, and an advanced 12-pin high-speed data bus. Retaining the large 54mm diameter of the classical EF mount, it enables ultra-fast aperture lenses such as the RF 28-70mm f/2L and 50mm f/1.2L.

View full Canon RF spec sheet →

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 →

Specification Comparison Table

9 Parameters
Parameter / Spec
Flange Focal Distance (FFD)
20.00 mm (0.787 in) 20.00 mm (0.787 in)
Inner Throat Diameter
54.00 mm (2.126 in — identical to legacy Canon EF mount) 51.60 mm (2.031 in)
Bayonet Tabs
3 asymmetrical stainless steel bayonet tabs with clockwise mounting twist 4 asymmetrical stainless steel locking tabs (high mechanical rigidity for cinema primes)
Electronic Interface
12 contact pins (high-bandwidth bidirectional bus for lens control ring and Coordinated IS up to 8 stops) 8 gold-plated electronic spring contacts (standardized cross-manufacturer protocol)
Camera Systems
Canon EOS R5 / R6 / R3 / R8 / R, Cinema EOS C70 / C80 / C400, APS-C EOS R7 / R10 Panasonic Lumix S5 II / S5 IIX / S1H / BS1H, Leica SL2 / SL3 / Q series, Sigma fp / fp L, DJI Ronin 4D
Legacy Adaptability
100% native AF/IS compatibility with all Canon EF/EF-S lenses via Canon EF-EOS R adapter (24mm spacer)
Lens Control Ring
Physical programmable control ring on all native RF lenses (aperture, ISO, exposure compensation)
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)