The Olympus M.Zuiko Digital ED 12-45mm f/4 PRO is a 24-90mm-equivalent zoom for Micro Four Thirds mirrorless cameras. Distinguished by its f/4 constant maximum aperture, this lens strikes a balance between a bright design and a highly compact design to suit its use in everyday situations. Myriad specialized elements are incorporated into the optical design, which helps suppress spherical aberrations, color fringing, and distortion in order to produce sharp, color-accurate imagery. A ZERO coating is also featured, which controls flare and ghosting for improved contrast when working in bright and backlit conditions.  Additionally, the lens is weather-sealed to enable its use in trying weather conditions. Constant f/4 maximum aperture enables consistent performance throughout the zoom range and helps to achieve a sleek and lightweight physical design. A ZERO (Zuiko Extra-low Reflection Optical) coating has been applied to individual elements to minimize lens flare and ghosting for improved contrast and color fidelity when working in strong lighting conditions. Minimum focusing distance of 4.7" at the wide end and 9.1" at the tele end pairs with an impressive 0.25x maximum magnification ratio to suit working with close-up subjects.