The manual focus Rokinon 8mm T3.1 Cine UMC Fish-Eye II lens is available for mirror less mounts. As a lens designed for shooting HD video, it offers features that differentiate it from "photo lenses," which, of course, can also serve to shoot HDSLR video. However, a Cine-dedicated lens, like the Rokinon 8mm T3.1, has a click less Aperture ring, which is not only silent but enables smooth transitions between stops and the ability to shoot between those stops. Furthermore, it relates Aperture in T-stops, which stands for Transmission-stops and denotes a more accurate measurement of the light entering through the lens, and provides a more consistent measurement from lens to lens. Additionally, a Cine lens features geared Aperture and focus rings to enable the use of focus pull apparatus such as a follow focus system.