<P> In cinematography, the dolly grip is a dedicated technician trained to operate the camera dolly . This technician places, levels, and moves the dolly track, then pushes and pulls the dolly and usually a camera operator and camera assistant as riders . If the dolly has a moveable vertical axis, such as a hydraulic arm, then the dolly grip also operates the "boom". If both axes are used simultaneously, this type of dolly shot is known as a compound move . </P> <P> A dolly grip must work closely with the camera crew to perfect these complex movements (cinematic techniques) during rehearsals . Focusing the lens is critical to capturing a sharp image, so a dolly grip must hit his or her marks in concert with a camera assistant who pulls focus . It is a skill that experience can hone to a point, but the best dolly grips are known for their "touch," and that makes them highly sought - after . </P>

What does a dolly grip do on a film set