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

Fujifilm X-Mount vs. Micro Four Thirds Mount

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

Comparing:
Fujifilm X-Mount
Micro Four Thirds Mount

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 Micro Four Thirds Mount, introduced in 2008 by Olympus and Panasonic as the first mirrorless system built as a dedicated open standard (rather than an adapted rangefinder mount, as with the earlier 2004 Epson R-D1), features a 19.25 mm Flange Focal Distance, a 38.0 mm throat diameter, and an 11-pin all-electronic bayonet interface. Governing an open consortium, it is used across OM System, Lumix, Blackmagic Design, and DJI aerial cameras.

View full Micro Four Thirds Mount spec sheet →

Specification Comparison Table

9 Parameters
Parameter / Spec
Flange Focal Distance (FFD)
17.70 mm (0.697 in) 19.25 mm (0.758 in)
Inner Throat Diameter
40.70 mm (1.602 in) 38.00 mm (1.496 in)
Bayonet Tabs
3 locking tabs with counter-clockwise mount twist 3 symmetrical stainless steel tabs
Electronic Interface
10 contact pins (opened to third parties in 2020: Tamron, Sigma, Voigtländer, Viltrox) 11 gold-plated electronic contacts (shared protocol between OM System and Panasonic)
Camera Systems
Fujifilm X-T5, X-H2, X-H2S, X-T30 II, X-S20, X-Pro3, X-E4 OM System OM-1 Mark II, Panasonic Lumix GH6 / G9 II, Blackmagic Pocket Cinema Camera 4K, DJI Inspire 3 X9 MFT
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
Historic Milestone
First mirrorless system built as a dedicated open standard, launched with the Panasonic Lumix G1 (2008) -- the earlier 2004 Epson R-D1 was a mirrorless interchangeable-lens camera, but on an adapted rangefinder mount, not a purpose-built open standard
Consortium Members
OM Digital Solutions (Olympus), Panasonic, Blackmagic Design, DJI, Sharp, Voigtländer, Laowa