The 1948 Olympic Television Cameras
There has been some interest in the television cameras that were used for the 1948 austerity Olympics, so I have written some notes that may be of use.
Television in the Great Britain of 1948 was very different from today and the importance of televising the 1948 Olympics could be judged by the space reporting the televising of them in the BBC yearbook of 1949, less than one page! It is possible that nine cameras were used. That is three from each of the OB vans. Six 1937 Emitron cameras and three of the new 1948 CPS Emitrons.
3 types of camera were used:-
The 1937 Emitron, the improved 1937 Super Emitron and the new in, 1948,
CPS* Emitrons
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This is the Long Necked version of the Emitron from 1937. The Emitron cameras started life with the "short neck" tubes, and later they were modified to take the improved "long necked" tubes. The cameras now had a bulge at the front to accommodate the extra tube length. It had a sensitivity of the order of 2500 Lux @ f3. The Emitron tube with its spherical glass enclosing the large target meant that the lens was a long way in front of the target and this placed constraints on the usable focal lengths and the depth of field in particular. “The older cameras were used in the stadium as they require much more light for satisfactory operation” [BBC yearbook] |
 The Super Emitron |
The Super Emitron had an Image Section in front of the target and this meant that the image from the lens was formed on this smaller photo target which was much nearer the lens thus removing many of the constraints suffered by the Emitron lenses. Additionally it was some 10 times more sensitive (200 Lux @ f2) enabling the use of telephoto lenses in poor light conditions. The Super Emitron tubes were retro fitted into 2 of the cameras and these had modified housings to accommodate the different shape tube. The bulge on the camera front now became a bulge on the side. It was necessary to rotate the whole tube to correct for the image rotation between the photo cathode and the target. It is not clear how many Super Emitron cameras there were, I have only been able to identify 2. This would make some sense in allocating one to each of the two pre-war OB vans. |
 The CPS* Emitron |
The CPS Emitron tube was of the orthicon class and the target
was at the front of the tube, optically good for the lenses. It
was scanned orthogonally from the rear so no keystone distortion
and it was also said that the CPS Emitron tube was free of the shading
problems of the Emitron tubes. The tube was even more sensitive
about 100 Lux @ f2 was required. |
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Both the Emitron and the Super Emitron tubes suffered from shading
(an effect similar to lens vignette or portholing, but much more pronounced
and unpredictable) and other spurious signals. Correction waveforms
had to be added to the picture signal to attempt to alleviate the
shading. These waveforms were called "Tilt and Bend" and
required frequent adjustment. Additionally because the target was
scanned from the side the beam that scanning the target had to have
corrections added to it to correct the distortion known as keystone
distortion. This 405 line image is before correction. |
Hello
and Welcome
to the virtual
Museum of the Broadcast Television Camera
It is my hope to make this site a valuable data resource covering the technical details of all the European and American television cameras that have been used for broadcasting or have some other special feature.
Bosch KCF-1 just added
The
site is still a long way from being finished! I keep adding new information
as and when I can, I have a lot of pictures to process, but there are
many pages that are incomplete with gaps and omissions.
There is a lot of information and pictures on this site and over the years
the style of the pages has evolved. I have not re-created the older pages
as I feel that my time is better spent adding new camera information.
Content over style!
Outline of site navigation :-
Thanks and acknowledgements to all who have helped in the creation of this site
Contact address = Brian@tvcameramuseum.nospam.org (remove .nospam)
The camera at the top left is a
Pye Mk4 and top right a Norelco
PC60
The monitor is a Pye grade 1 type 2780 405 line from the mid 1950s