Micro Four Thirds Mount
Lens Mounts · 7 specs
Direct Answer
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.
Source: Four Thirds System Consortium Standards / CIPA · Last reviewed Aug 28, 2026
Specs
| Flange Focal Distance (FFD) | 19.25 mm (0.758 in) |
| Inner Throat Diameter | 38.00 mm (1.496 in) |
| Bayonet Tabs | 3 symmetrical stainless steel tabs |
| Electronic Interface | 11 gold-plated electronic contacts (shared protocol between OM System and Panasonic) |
| 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 |
| Camera Systems | OM System OM-1 Mark II, Panasonic Lumix GH6 / G9 II, Blackmagic Pocket Cinema Camera 4K, DJI Inspire 3 X9 MFT |
The Open Interoperability Standard
Micro Four Thirds was one of the first photographic mounts shared seamlessly across competing camera brands (a pattern the L-Mount Alliance later adopted for full-frame). A Panasonic Leica DG lens mounts with full autofocus, aperture control, and optical stabilization on an OM System camera, and an M.Zuiko Olympus lens functions flawlessly on a Blackmagic cinema camera.