Olympus M.ZUIKO DIGITAL ED 12-40mm F2.8 PRO lens review: Pro worthy performer

Introduction Announced at the same time as the firm’s new flagship OM-D E-M1 model, this new high-grade wide-angle to short-telephoto zoom is the equivalent to a 24-80mm and boasts a constant f2.8 maximum aperture that will appeal to stills photographers and movie-makers alike.  As with other high-grade lenses from Olympus, it has a push/pull focus collar with a declutching mechanism to switch quickly between manual- and auto-focus.Internally, the new lens has a high-speed linear AF motor for fast, near silent autofocusing, a new dust-, drip- and freeze-proof design and a complex optical construction consisting of 14