Using a follow focus

Brian Liepe: A follow focus allows the operator or first assistant camera person to maintain …focus on a moving subject without touching the lens directly, which can sometimes increase …the risk of shaking the camera or lens. …The lens must be wrapped with a gear which has teeth that are of a corresponding pitch. …Now the pitch just refers to the distance between the peaks and the valleys on that gear. …You can use a grease pencil or dry erase marker to indicate points on the marking disk that …correspond with the actor's movements in the scene.…

This way you can follow the subject and pull the focus accordingly. …They're pretty cool. I like them. I use them a lot. …