Marconi MkIII Television Camera Viewfinder type 2158
Type 2158A - 405Lines 50 Fields
Type 2158B - 525Lines 60 Fields
Type 2158C - 625Lines 50 Fields
5 inch CRT type MW13-35 with 8Kv EHT. Maximum brightness 15 foot-lamberts.
9 Valves types 12AT7, 12AU7, EL81, 6U4GT. The 2158B was fitted with USA valve types.
The viewfinder connected to the camera via two 8 pin Painton connectors.
The CRT was supplemented by a 2x magnification lens mounted in the visor assembly. there were indictors for the lens in use and Cues in the viewfinder.