Focus puller

A focus puller, or 1st assistant camera, is a member of a film crew’s camera department whose primary responsibility is to maintain image sharpness on whatever subject or action is being filmed.

"Pulling focus" or "rack focusing" refers to the act of changing the lens’s focus distance setting in correspondence to a moving subject’s physical distance from the focal plane. For example, if an actor moves from 8 m away from the focal plane to 3 m away from the focal plane within a shot, the focus puller will change the distance setting on the lens during the take in precise correspondence to the changing position of the actor. Additionally, the focus puller may shift focus from one subject to another within the frame, as dictated by the specific requirements of the shot (cinematic techniques).