15-07-2021, 01:16 PM
(08-07-2021, 02:20 PM)ppppenguin Wrote: EMI developed printed circtui scan coils for the EMI 2001 colour camera. These gave very precise coil geometry. This was essential for matching the 4 tubes in the camera. The 2001, along with the Marconi Mk VII were the only two 4 tube cameras that were made in an numbers. The idea was that a separate luminance (Y) tube gave better pictures and reduced RGB registration problems. In practice it was expensive and bulky. Never done again. Later cameras took fine detail from the green channel only wihch was a perfectly good approximation to Y.
Here's a photo from a booklet about 50 years of EMI research labs. Other photos include early TV, sound recording, radar and CT scanning. Remember that the CT scanner as we know it was invented by Godfrey Hounsfield at EMI CRL.
Yes 'contours out of green' was a good idea, we must remember cameras using that technique were somewhat 'blind' to red/blue transitions. I believe the thinking behind the idea was that such transitions occurred relatively infrequently in 'real life' so there was not too much concern, especially given the considerable advantages in practice.
From memory I think we referred to such cameras as 'GRB' cameras, and I believe some european manufacturers produced YRB models too?
