Museum of the Broadcast Television Camera

Marconi MkIII Television Camera with Taylor Hobson Varotal Zoom lens

Marconi MkIII Television Camera with Taylor Hobson Varotal Zoom lens

In the Marconi implementation of the Taylor Hobson zoom the whole camera turret was replaced. it had a support arms to the front to support the Zoom body. The controls, zoom & focus extending on both side to the camera rear. It made for a very big camera, but not unusual at the time.

 

The studio version focal length was 4 to 20 inches and the OB version 8 to 40 inches.

 

Other UK manufacturers (Pye & Watson) also used a "sledge" running the length of the camera and zoom with chain drives to the lens.

 

It's worth mentioning that the normal focus control has to be correctly set, the "back focus" so that the image remains in focus as the zoom progresses. It is likely that once set the cameraman would have removed the control, lest it be knocked in use.