Marconi colour television camera dichroic colour separation unit
This view, with the housing removed, shows the dichroic unit, the gelatine absorption filters and the front silvered mirrors. This unit separates the light into the three primary colours and directs it on to the tube photocathodes. The tubes are at splayed out at a slight angle.
John Winn writes:-
"They are the original mirror optics. The astigmatism correctors at the front were not necessary for the prism optics as they corrected the horizontal mirrors. The prism had a 1//4 wave plate to cancel horizontally polarised light passing through to the green tube giving green hair and green piano keys from back lit objects."