Dolly grip
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.
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 talents.
A dolly grip is also employed when the camera is operated in handheld mode (on the operator's shoulders or literally in their hands). While the camera operator is moving with the camera, the dolly grip is responsible for the operator's safety, helping the operator to "blindly" negotiate sometimes complicated environments. The dolly grip silently directs the operator (through gentle touches, nudges, pulls and pushes) away from walls and other obstacles that the operator cannot see while concentrating on the image in the camera viewfinder. The same is true when the camera is operated with a Steadicam or similar body-mounted stabilization tool.
