微4/3系统
Following the introduction of the Micro Four Thirds system, several other cameras were released by Panasonic and Olympus, with the Olympus PEN E-P1 (announced June 2009) being the first mirrorless camera in a compact size (pocketable with a small lens). The Samsung NX10 (announced January 2010) was the first camera in this class not using the Micro Four Thirds system, instead utilizing a new, proprietary lens mount (Samsung NX-mount). The Sony Alpha NEX-3 and NEX-5 (announced May 14, 2010, and released in July 2010) saw Sony enter the market with a new, proprietary lens mount (the Sony E-mount), though the camera included LA-EA1 and LA-EA2 adapters for the legacy Minolta A-mount.