Micro Four Thirds System - Lens Mount

Lens Mount

The MFT system design specifies a new bayonet type lens mount with a flange focal distance of slightly under 20 mm – half as deep as the Four Thirds system design. By avoiding internal mirrors the MFT standard allows a much thinner camera body. Viewing is achieved on all models by live view electronic displays with LCD screens. In addition some models feature a built-in electronic viewfinder while others may offer optional detachable electronic viewfinders, or even as an option an independent optical viewfinder typically matched to a particular non-zoom "prime" lens. The flange diameter is about 38 mm, 6 mm less than that of the Four Thirds system. Electrically, MFT uses an 11-contact connector between lens and camera, adding to the nine contacts in the Four Thirds system design specification. Olympus claims full backward compatibility for many of its existing Four Thirds lenses on MFT bodies, using a purpose built adapter with both mechanical and electrical interfaces.

The shallow but wide MFT lens mount also allows the use of existing lenses including Leica M, Leica R, and Olympus OM system lenses, via Panasonic and Olympus adapters. Aftermarket adapters include Leica Screw Mount, Contax G, Canon, Nikon, and Pentax, among others. In fact, almost any still camera, movie or video camera interchangeable lens that has a flange focal distance greater than or marginally less than 20 mm can often be used on MFT bodies via an adapter. While these so-called "legacy" lenses can only be used in a manual focus, manual aperture control mode on MFT cameras, hundreds of lenses are available for use, even those that survive for cameras no longer in production.