Micro Four Thirds system

The Micro Four Thirds system (MFT or M4/3 or M43) (マイクロフォーサーズシステム, Maikuro Fō Sāzu Shisutemu) is a standard released by Olympus Imaging Corporation and Panasonic in 2008,^[1] for the design and development of mirrorless interchangeable lens digital cameras, camcorders and lenses.^[2] Camera bodies are available from Blackmagic, DJI, JVC, Kodak, Olympus, OM System, Panasonic, Sharp, and Xiaomi. MFT lenses are produced by Cosina Voigtländer, Kowa, Kodak, Mitakon, Olympus, Panasonic, Samyang, Sharp, Sigma, SLR Magic, Tamron, Tokina, TTArtisan, Veydra, Xiaomi, Laowa, Yongnuo, Zonlai, Lensbaby, Venus Optics and 7artisans amongst others.

The specifications of the MFT system inherit the original sensor format of the Four Thirds system, designed for DSLRs. However, unlike Four Thirds, the MFT system design specification does not require lens telecentricity, a parameter which accommodated for the inaccurate sensitivity to off-angle light due to the geometry of the photodetectors of contemporary image sensors. Later improvements in manufacturing capabilities enabled the production of sensors with a lower stack height, improving sensitivity to off-angle light, eliminating the necessity of telecentricity and decreasing the distance from the image sensor at which a lens's rear element could be positioned without compromising light detection.^[3] Such a lens, however, would eliminate the room necessary to accommodate the mirror box of the single-lens reflex camera design, and would be incompatible with SLR Four Thirds bodies.

Micro Four Thirds reduced the specified flange focal distance from 38.67mm to 19.25mm. This reduction facilitates smaller body and lens designs, and enables the use of adapters to fit almost any lens ever made for a camera with a flange distance larger than 19.25mm to a MFT camera body. Still-camera lenses produced by Canon, Leica, Minolta, Nikon, Pentax and Zeiss have all been successfully adapted for MFT use – as well as lenses produced for cinema, e.g., PL mount or C mount.