Samyang 135mm T1.5 AS UMC VDSLR II Lens for Sony E-Mount is a manual focus prime lens. It provides a maximum aperture of T2.2 for effective low light capture and shallow depth of field control and a 9 blade iris for attractive bokeh. Optimized for cinema and video applications, the focus and aperture control rings are outfitted with industry standard gearing, which provides an interface for working with a traditional follow focus. The aperture control ring has also been de-clicked, which enables smooth iris pulls. In addition, bright aperture and distance markings are printed on the lens barrel facing laterally to facilitate easier control by a focus puller. The lens has a minimum focus distance of 2.6'. Internal focusing minimizes the effects of focus breathing, and the lens is composed of 11 elements in 7 groups. A lens multi-coating helps to improve light transmission reducing flare and ghosting. The filter thread diameter for attaching sunshades or filter rings is 77mm. Each of the VDSLR II lenses will offer the same position of their geared focus and aperture rings so that follow focus and other rig accessories won't need re-adjustment when swapping lenses. Also, each lens is tested to be color matched with the other lenses in the series and provide the same color and contrast when shooting video, allowing you to add lenses to your kit over time without worrying about the color of your image changing significantly when swapping lenses. As an aid to focus pullers, the lenses are marked with focusing scales on each side of the barrel for easier adjustment from both sides of the camera.