The Cine AF Pro Controller enables you to add precise manual focus control to your Cine AF lenses. The Pro Controller easily attaches to the front of any Cine AF lens with a unique front bayonet mount, giving filmmakers and videographers total control over focus. The Pro Controller features a dual scale with both feet and meters, and fine focus adjustments can be made with a smooth 300 rotation. The focus ring has an industry standard 0.8 MOD and can be combined with any follow focus. When the Pro Controller is attached, the focus ring on the lens can be used as an aperture ring. A tally lamp on the front lets the subject or photographer know if the camera is in a recording or in standby state. The front of the Pro Controller is compatible with 95mm matte boxes. Lens firmware must be updated to the latest version in order to use all the new features of the Pro Controllerproperly