Dallmeyer made a range of lenses for tv cameras. The image shows a 'Super Six' 4"-inch f/1.9. To complicate matters, each brand of tv camera needed a dedicated lens mount. The one pictured is for a Pye Mk 3 camera. Note the four studs on the top of the mount. These were used to automatically or remotely adjust the iris when the 'taking' lens was positioned in front of the image tube.
The two red marks on each side of the lens are a colour code to indicate, in this instance, 'Camera' One, (BBC Bristol OBs -MCR 12 circa 1955).
DALLMEYER TELEOG 25" inch f/5.8-32 ‘folded’ telephoto lens. Marconi MkIII fitting (type TV 88). The lens barrel unit was made by Cox, Hargreaves & Thomson Ltd. The lens itself is ex-BBC MCR 9 (Wales) These large lenses overcame length by using a periscopic method to 'fold' the light path with an internal angled mirror. The lens usually travelled in a heated box as condensation could play havoc with the picture quality if care was not taken, especially perched atop a gantry in a force ten rain storm with no easy access to maintenance.
An example of a Dallmeyer DALMAC lens: 5"-inch f/3.5. This lens is dated 1951 and it fitted onto the turrent of a Marconi Mk II image orthicon monochrome tv camera. The 'sleeve' around the front of the barrel was a toothed ring, linked to an 'auto iris' servo motor. The rear attachment was a bayonet system.