EMI 2001
Even though semiconductors were used in most of the camera, the highly sensitive head amplifiers still used thermionic valves in the first generation of the design.
The pull-out handles at each corner needed four people to safely move the camera with the lens in place.
It also required a separate remote camera control unit and the cable connecting the two was over 2 inches thick.
The EMI 2001 used a four-way prism assembly to split the light into its components, using the same novel principles that had been developed by Philips for its three-way splitter.
The problems previously experienced with double imaging (common with plate glass dichroic mirrors) were also eliminated.
[1] Consequently, EMI chose to use a four-tube version of the prism splitter for its new colour camera,[3] in order to retain all the advantages of the method.
In addition, the application of gamma correction to the signals further complicates the situation (display tubes have, approximately, a square law characteristic with γ ≈ 2.2).
The circuitry in the 2001 was all solid state apart from the pick-up tubes and, in the early cameras, the first stage of the head amplifiers.
[10] The circuit maintains its bandwidth as the gain is increased (by reducing R2), unlike a conventional voltage feedback op.
The wide-band luminance channel had its bandwidth defined by a linear phase low pass filter with a 3 dB cut-off at 6.8 MHz.
The problems arose when the beam current of a pick-up tube was insufficient to fully discharge the target in very bright areas of an image.
As supplied by EMI, the 2001 and the later 2001/1, did not have any form of ACT (anti-comet tail) or HOP (highlight overload protection).
None of the first generation of true broadcast cameras in the middle to late 1960s had ACT, so the EMI 2001 was not unusual.
When observing old recordings, such as those from the 2001, it is very easy to tell if a programme used EMI 2001s (or any other first-generation PAL colour camera) to capture the images as the comet tails would often be coloured "blobs" or "splodges" (usually caused by a light source or light reflecting off a highly reflective or polished surface) simply because the camera did not have ACT circuits.
When the EMI 2001 was ready for production in early 1968, the Marconi Mk VII cameras the BBC ordered [6][28] were moved to the weather, news and presentation studios in Television Centre (where movement would be less of an issue as camera operators had complained of discomfort from operating them with unusual postures).
EMI engineers visited the United States in 1963, in order to view RCA's new four-tube colour camera, the TK42.
The construction took only six weeks of intensive effort, aided by the cannibalization of parts from existing EMI cameras.
This camera contained three Vidicon tubes and a colour-splitting system using plate glass dichroic mirrors.
The camera was housed in a simple box-shaped structure with ribs of extruded aluminium and plain side panels.
At that time, the BBC was evaluating an early Philips three-tube camera which used some newly available Plumbicon pick-up tubes.
In spite of the BBC's lukewarm reception of the experimental camera EMI persisted with the four-tube concept, but now using Plumbicon tubes, as suggested by Wood[17] although there was some delay before the work started.
The camera was to use four Plumbicon pick-up tubes and solid state circuitry, include a zoom lens as standard and to use prism optics.
The BBC and many of the independent TV companies installed the cameras in their studios during the rapid expansion of the UK colour services after 1967.
In addition, rival companies were already bringing out new designs and EMI now found only a limited market for a camera with a four-tube configuration.
First produced in 1966, by the early 1970s almost all of BBC Television's studios and many outside broadcast (OB) units were equipped with the 2001.
The Thomson 2001s, like the EMIs, also used Plumbicons; however, due to a brochure which was printed in French, it was presumed that they used Vidicon tubes.
Furthermore, when EMI closed-down the Broadcast Equipment Division in the late 1970s, studios were deprived of technical and spares support for their cameras.
This set severe demands for the lens designer, but Angenieux was able to achieve EMI's requirements, provided that field flattening lenses were fitted in front of each pick-up tube.
In addition, incorporating the servo drivers within the camera body precluded the use of other makes of zoom lens.
[44][45][46][47] With no protruding zoom lens, the studio camera was only 537mm long enabling it to be used in small spaces and to be panned very easily (it had a low moment of inertia).
