The OM System 40-150mm F4.0 PRO is a weather-sealed telephoto zoom lens that offers an 80-300mm full-frame equivalent field of view. The lens is IP53 rated for dust- and splash-resistance when paired with a weather sealed camera, such as OM System's new OM-1 Micro Four Thirds camera. It's constructed of 15 elements in nine groups, uses a seven-blade circular aperture diaphragm and has a minimum focusing distance of 70cm (27.5"). The lens' autofocus (AF) is driven via OM Systems’ Movie & Still Compatible (MSC) system, which OM Systems claims ‘benefits both photo and video applications due to its smooth, quiet, and fast performance.’
