The Samyang Optics 14mm T3.1 VDSLR ED AS IF UMC II is a wide-angle lens with manual focus designed for full-frame sensors. It has been specifically developed for professional film and video work, featuring a focus gear ring for follow focus systems. With the decoupled aperture gear ring, you can change the aperture quietly and smoothly. The T-number, which indicates the actual amount of light transmission, and the distance scales are marked on both sides of the lens for precise filming. The lens operates with a manual aperture system and a low T-number, allowing for natural shooting under various lighting conditions.