Dolly tracks used for heavy cameras have traditionally been constructed of
steel or
aluminium. Steel, although heavier than aluminum, is less expensive and withstands heavier use. Longer track segments, while heavier to transport, allow track to be laid straighter with less effort.
Curved track is also available. Plastic versions of track have been used with lightweight dolly systems. In the 2000s, flexible rubber track allowed quicker set up and easier transportation for use with light cameras.
The camera dolly may be used as a shooting platform on any surface but is often raised onto a track, to create smooth movement on a horizontal axis known as a
dolly shot.
Additionally, most professional
film studio dollies have a hydraulic
jib arm that raises or lowers the camera on the vertical axis. When a
dolly grip operates a dolly on perpendicular axes simultaneously, it's known as a compound move.
Dolly moves may also be executed without track, giving more freedom on the horizontal plane and with it, a higher degree of difficulty. These are called dancefloor moves and may either be done on the existing surface (if smooth enough) or on an overlay designed for dolly movement.
The ground overlay usually consists of thick
plywood as a bottom layer and
masonite on top.Camera dollies have several steering mechanisms available to the dolly grip.
The typical mode is rear-wheel steering, where the front wheels remain fixed, while the wheels closest to the operating handle are used to turn.
A second mode, round steering, causes the front wheels to turn in the opposite direction from the rear wheels. This mode allows the dolly to move in smooth circles and is frequently used when the dolly is on curved track.
A third mode, called
crab steering, is when the front wheels steer in the same direction as the rear wheels. This allows the dolly to move in a direction diagonal to the front end of the dolly.
Dolly tracks used for heavy cameras have traditionally been constructed of steel or aluminium. Steel, although heavier than aluminum, is less expensive and withstands heavier use. Longer track segments, while heavier to transport, allow track to be laid straighter with less effort.