MFT Mount

The Micro Four Thirds mount is the mechanical and electronic interface between M43 camera bodies and lenses. It was defined jointly by Olympus and Panasonic in 2008 as an open standard, meaning any manufacturer can license it and produce compatible products. The mount has a 44mm inner diameter and a flange focal distance of 19.25mm — the distance from the rear of the lens mount to the sensor plane. The short flange distance, made possible by removing the mirror box required in DSLR designs, allows for more compact lens and body combinations.

The MFT mount is an electronic mount. It passes power from the camera body to the lens for autofocus motors and electronic aperture control. It also transmits metadata from the lens to the body, including focal length, aperture, and stabilisation data. This communication enables features like IBIS synchronisation with OIS lenses, and in Panasonic bodies with compatible lenses, Dual IS coordination. Manual focus legacy lenses from other systems can be adapted to the MFT mount with passive mechanical adapters, but without electronic communication, IBIS cannot receive focal length data and must be set manually.

The open standard nature of the MFT mount has attracted a wide range of manufacturers beyond the founding partners. Third-party lens makers producing native M43 lenses include Sigma, Laowa, Voigtlander, 7Artisans, TTArtisan, Samyang, and others. This has made M43 one of the most lens-rich mirrorless systems by native lens count. The MFT mount specification ensures physical and basic electronic compatibility across all compliant products, though advanced features like Dual IS coordination require manufacturer-specific firmware support in both body and lens.