The Rokinon 300mm f/6.3 Mirror Lens is Rokinon"s first mirror lens designed for mirrorless interchangeable lens cameras. These cameras include the Olympus Pen Cameras, Sony NEX cameras, Fuji X & Canon M cameras. Constructed with 9 element in 9 groups, this compact lens fits proportionately to your camera and is the perfect size. Sharp optics, using both refractions and reflections, provide the user with an extremely sharp picture with Minimum color aberration. This Rokion mirror lens features a fast F6.3 aperture for much brighter images. This lens is strong and powerful, ideal for sports, nature & wildlife photography.