Worrall Geared Head
The particular head pictured is LT-1-1060 ser. 244. It has two speed transmissions for both pan and tilt. It features a trimable 5/8ths threaded (springed plunging) pin to attach the camera with, and has a mitchell mount for attaching to support. The control wheels are detachable for transport and both gear sets can be totally disengaged to reduce the risk of damage in transport. The head can manage weights up to 200lbs, with the camera properly balanced on the head.
The worrall is useful as a nodal head, which means the center axis of tilt is above the head in the area of the camera. For certain types of precision photography positioning the camera's aperture in the nodal position is desirable. Also, the radius around the nodal point lends itself to balancing different sizes of cameras. A fully loaded Mitchell BNCR will not rock back from an extreme tilt up or down. It is balanced so that the tilts are smooth and under no pressure from the weight of the camera. To get this same effect with a smaller camera either elevated weights would have to added above the camera or a smaller nodal head would have to be used.
A major advantage to using a geared head is the precision with which cameras moves can be duplicated. By expressing camera moves in terms of number of rotations of the pan and tilt controls moves can be copied precisely from take to take. This method also makes for smooth pans on animation sets, where the pan can be broken into fractions of a rotation for each frame.
Worrall heads are very heavy and difficult to use. It takes many days, weeks, even years of practice to become proficient at keeping a camera trained on moving subject using the Worrall head.