The Samyang 135mm T2.2 is a manual focus lens with Micro Four Thirds mount that allows for delicate, artistic video work. The focus gear ring is installed for follow focus system. You may change the aperture quietly & smoothly with the uncoupled aperture gear rings. Also, distance scale & T numbers are marked on both sides of the lens for convenience. This telephoto prime expresses vibrant colour & soft out-focusing area which makes it the best lens to shoot portrait, night scenery, wildlife & journalism photography.