More Answers To Some Early Iconoscope Camera Questions…
More Answers To Some Early Iconoscope Camera Questions…
With close scrutiny to dates, and with new images in hand from the early days at CBS Studios at Grand Central, I think we can conclusively say that the switch from the dark umber gray color to the silver body came in May of 1941. It seems that this was the signature of the new A500 upgrade as you will read below. May 1941 is when TV went from 441 lines to 525 lines of resolution.
In 1935, when they went into service in NBC Studio 3H, they were 220 line camera, but went to 441 lines in June of ’38. Many had said that the jump to “high definition” brought the cosmetic change, but it did not. Remember, the camera housings were constant…only the Iconoscope tubes and a few changes inside were required.
A new photo has helped answer when CBS got their RCA Iconoscope cameras, and this A500 question. In the photos below, the center shot of the dark RCA Iconoscope camera in CBS Studio 41 was taken September 1, 1939, so we now have a first sighting date of an RCA Iconoscope camera at CBS.
The second CBS photo, with the silver camera body, was taken in December of 1941, and shows the CBS cameras have also been updated by RCA with both the new 525 line tubes and the silver exterior that apparently was the mark of the A500 series conversion. More to come today, and more on the photos! Enjoy and share! -Bobby Ellerbee
Are you sure there was a change to the Iconoscope tube when the NTSC-1 standards were adopted? My understanding is that the switch from 441 to 525 lines simply traded horizontal resolution for vertical, in part because it was felt that the image would degrade less over long coaxial or radio relay links. In the 1940 book “Television” by Zworykin and Morton, the authors state “A good experimental Iconoscope should resolve the [illustrated test] pattern down to at least 600 to 800 lines. Since often the video amplifier response is limited to 3 or 4 megacycles, the resolution of the picture seen on the Kinescope under normal conditions may be limited by the system.” (The standard at the time the book was written was still 441 lines.) There are pages of algebraic equations that explain why 441 lines was optimal for the bandwidth of the channel, but I’m not going to try to explain something I hardly understand myself. : -)
Here is some 1939 footage of these camera’s in operation: https://youtu.be/jApD3VIZu_4?t=67 (Skip to 1:07)
I find it interesting that the cam ops are gripping the handles above the rubber? grip. In essence they are “choking up” on the handle. In both shots they are gripping them this way and in the third shot one can see the dirt from the hands that have gripped that cam handle in the same way. Most curious.
Does anyone know the size of the image formed on the tube?
I think that’s interesting considering the current popularity of so-called large sensor cameras, that must be tiny compared to these.
And people complained about the recent HD format wars 🙂
What did the two lenses accomplish, Bobby?