The Olympus PEN E-P1 announced on June 16th, 2009 is Olympus Corporation's first camera that uses the Micro Four Thirds mount. The first camera to use the Micro Four Thirds mount is Panasonic's G-1 camera.The Olympus E-P1 does not have an optical or electronic viewfinder and uses a live preview screen, although an optical viewfinder is included in a kit also comprising the camera and the 17 mm lens. It autofocuses using contrast-detection autofocus or face detection in live view mode.
The design of the camera is reminiscent of the Olympus PEN half frame film cameras and is marketed as the Olympus digital PEN. The model presented on June 16, 2009 is very similar to the Olympus PEN F. Initially, two lenses will be available from Olympus, one 14–42mm f/3.5–5.6 zoom and a 17mm f/2.8 "pancake" prime lens.
The new 17mm f/2.8 pancake lens or the 14–42mm f/3.5–5.6 zoom lens are of the Micro Four Thirds lens mount which means they're smaller than Four Thirds but with an adapter, they can be fitted to a Micro Four Thirds body.