The samyang 8mm t31 video umc fisheye ii lens with canon ef m mount is a compact manual focus fisheye lens with bright t31 aperture and extremely wide angle of view designed exclusively for video work on canons eos m compact system camera this video digital slr cine lens is fitted with a de clicked aperture and special mechanisms to make it rack compatible and allow use with the follow focus system to ensure smooth quiet and accurate rotation of focusing this also means you can now easily