Museum of the Broadcast Television Camera

EMI field sequential colour TV Chromacoder equipment

D.G. Perkins adjusting the experimental "Chromacoder" equipment.

EMI built an experimental colour camera with a rotating filter. The camera was known as a sequential colour type, i.e. you got a green picture, then red followed by blue, hence the need for the high frame rate to reduce colour flicker and colour fringing on moving objects. These were the Achilles heels of the sequential colour cameras and they did not offer a picture that was compatible with black and white TV sets. The advantage of this type of camera was it was not much more complex than a monochrome camera and it was relatively inexpensive, the problem was how could this type of camera be made compatible. The answer was a kind on optical standards converter. It had 3 CRTs one for each colour with 3 monochrome cameras looking at them. This fixed the frame rate and converted the signal from sequential to simultaneous. It was not with out its problems, this was like a 3 tube camera, registration and all. What was a simple system was now complex.

"British Radio and television" November 1954 page 491.
"Practical Television" July 1952 and December 1954 page 296.


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