1954 NTSC “Correct” Video.

[etype2]

A VK member wrote on his website :

“ Through years of eclectic research and dedication, Ed (Reitan) provided examples of early color video programs on DVD that duplicated the early color video signals enjoyed by those few who owned color television sets in 1954, 1955, and to the end of the 1950’s.”

I believe this was in connection with a presentation at the 2007 annual Early Television Foundation convention of a CT-100 displaying “correct” NTSC color video as it was seen in 1954.

I did not attend the convention and curious as to what program content was displayed on the CT-100 and wondering if that content is still available.

[Penthode]

Original NTSC would suggest following correctly the original color space and adhering to Illuminant C white. In addition separately the full chrominance resolution. This assumes later broadcast equipment up to the digital studio revolution and component 4:2:2 video became the norm.

I do not know how Ed would have claimed a DVD conveying the original NTSC broadcast format because the DVD itself normally would contain digitally compressed MPEG2 video, which I suppose would provide a signal that through a proper NTSC encoder could provide a higher luminance and chrominance resolution. And if the color space was accurately aimed at the original spec, that could be achieved as well.

[old_tv_nut]

You must be referring to this:
https://www.earlytelevision.org/2007...on_reitan.html

I think Ed's statement about this representing the actual color as seen on sets at the time was very wishful thinking.
First of all, it wasn't videotape but a color kinescope film, which would not have exhibited accurate color even when brand new.
Second, it was a Da Vinci restoration from scanning a badly faded color kinescope film, so the reproduction would be adjusted by eye rather than to a test pattern.

But wait, you say, maybe the film had colorbars or something known? Well, a color kinescope film could not possibly reproduce the bright, pure colors of a test pattern. If the restoration were adjusted to do that, all the more subtle colors, like flesh tones, would be unacceptably off.

So, the color in this demo may have been subjectively very good, but it would have had little accuracy in reproducing the original live viewing experience.

[etype2]

Thank you both for your comments. So the best we can do is approximate?

I’m sure I’m not the only one who wonders what original 1954-55 NTSC color would like today on their calibrated Westy with 15GP22 or a CT-100. I was there to see original 1956, probably misadjusted color on my Uncle’s set and have visual memory of it.

I’m amazed that the very early color tapes (kinescopes until tape came along) were not preserved by the broadcast engineers, or were they, but just squirreled away? What we have today is Milton Berle and Astaire from 1958. Eisenhower does not count, was not a television production. The link provided gives insight. Often thought about contacting DC Video.

[old_tv_nut]

The ideal would be a NTSC tape played on its original type of machine with no adjustments beyond chroma amplitude and phase, and viewed on a 15GP22. Any additional stages in between (like decoding the NTSC into YCrCb for DVD and recoding as NTSC composite DVD player output) likely will (or in many cases definitely will) introduce modfications to match (or mismatch) modern TVs, monitors or computer screens.

A colorimetric analysis of the TK-41 spectral response shows that it was an excellent match to the original NTSC phosphors. This quickly went haywire as TV makers changed the white point and the phosphor primary colors themselves (particularly the green, but also the blue) in the quest for brighter pictures, and further when later camera makers tweaked the cameras to cater to the newer receivers and monitors. The train didn't get back on track until PAL standardized their cameras to match the modern phosphors. Then sRGB for computer stills and the color standards for HDTV also adopted the same primaries. This doesn't mean that camera makers necessarily did it by the book. Sony HD cameras in particular had a color rendition all their own, with particularly bright yellows - but the standardization meant that they could guarantee that all HDTVs would show the colors the way Sony intended. The Sony camera color may have been fudged to show the paler skin tones preferred in Japan, but I don't know for sure. I do know that we had to modify the matrix in the early Sony cameras to match the standard colors on the test chart (which the BTS cameras already did) when we were creating the subjective comparison test material for the U.S. HDTV format wars.

[DVtyro]

With movies receiving a completely different color palette during remastering, I would not care for old TV programs. As long as skin is not blue, and streetlights have discernible red, yellow and green colors, it is good enough.

[ARC Tech-109]

To me it's the historical value that outweighs the color accuracy.

[etype2]

Originally Posted by old_tv_nut

The ideal would be a NTSC tape played on its original type of machine with no adjustments beyond chroma amplitude and phase, and viewed on a 15GP22. Any additional stages in between (like decoding the NTSC into YCrCb for DVD and recoding as NTSC composite DVD player output) likely will (or in many cases definitely will) introduce modfications to match (or mismatch) modern TVs, monitors or computer screens.

A colorimetric analysis of the TK-41 spectral response shows that it was an excellent match to the original NTSC phosphors. This quickly went haywire as TV makers changed the white point and the phosphor primary colors themselves (particularly the greeen, but also the blue) in the quest for brighter pictures, and further when later camera makers tweaked the cameras to cater to the newer receivers and monitors. The train didn't get back on track until PAL standardized their cameras to match the modern phosphors. Then sRGB for computer stills and the color standards for HDTV also adopted the same primaries. This doesn't mean that camera makers necessarily did it by the book. Sony HD cameras in particular had a color rendition all their own, with particularly bright yellows - but the standardization meant that they could guarantee that all HDTVs would show the colors the way Sony intended. The Sony camera color may have been fudged to show the paler skin tones preferred in Japan, but I don't know for sure. I do know that we had to modify the matrix in the early Sony cameras to match the standard colors on the test chart (which the BTS cameras already did) when we were creating the subjective comparison test material for the U.S. HDTV format wars.

Very interesting, so now I have to find a quad machine. :-)

In a 1954 publication, Westinghouse claims the red phosphor in the 15GP22 had a “slow persistence causing fuzzy images”. Would this be one one of the reasons phosphors were changed? I know brightness as you say was an issue.

[dtvmcdonald]

I have done a careful job of producing still pictures that adhere to the original standard, including correct color matrixing and correct pre-filtering of the I
and Q channels. They start from Canon cmaera digital images processed to Adobhe RGB. These I display on my carefully adjusted CT-100. The results are extremely good,
compared to the originals on a Adobe-compliant monitor.

Its an entirely a bogus quest: I don't care what the original was, a proper
1990s Trinitron used as a display devi9ce for a CT-100 as tuner (RGB outputs
to grid of a nonexistant 15GP22 converted to input for the monitor look great.
This is true for any quality picture source. All the unmatchings don't make the colors look any less great. I watches last night's CFP game on my CT-100,
about 3 feet from the screen, with the proper glasses to be in focus.
It looked great. The only problem I actually noticed is that the goal posts are lacking in their yellow color.

Now watching a Vikings-Seahawks game via NTSC is different matter: both uniforms are very neary pure Q. Its blur city.

[ARC Tech-109]

Watching the Vikings is a blur, this coming from a minnesotan.

[old_tv_nut]

Originally Posted by etype2

Very interesting, so now I have to find a quad machine. :-)

In a 1954 publication, Westinghouse claims the red phosphor in the 15GP22 had a “slow persistence causing fuzzy images”. Would this be one one of the reasons phosphors were changed? I know brightness as you say was an issue.

I haven't noticed an overly long persistence in the CT-100s I've seen, but I wasn't looking for it - interesting. The major reason for changing the red phosphor was for greater efficiency and therfore picture brightness, since it required much more current than the green or blue. An interesting note is that subsequent red phosphors were close in color to the original, except for the zinc cadmium sulfide in the all-sulfide tubes, which turned more orange than the original at high currents.

Edit: is it possible this comment refers to experimental tubes that preceded the production version of the 15GP22?
I have read that some early prototype tubes had a red phosphor that required using a color filter over the face, making for a really dim picture; not sure about the persistence.

[old_tv_nut]

Originally Posted by dtvmcdonald

I have done a careful job of producing still pictures that adhere to the original standard, including correct color matrixing and correct pre-filtering of the I
and Q channels. They start from Canon cmaera digital images processed to Adobhe RGB. These I display on my carefully adjusted CT-100. The results are extremely good,
compared to the originals on a Adobe-compliant monitor.

...

That's great.

[etype2]

Originally Posted by old_tv_nut

Edit: is it possible this comment refers to experimental tubes that preceded the production version of the 15GP22?
I have read that some early prototype tubes had a red phosphor that required using a color filter over the face, making for a really dim picture; not sure about the persistence.

Exact quote from WESTINGHOUSE ENGINEER MAY 1954:


Was it possible that Westinghouse had early access to prototype CRT’s? Yes, but in the article, they talk about production CRT’s and only the 15GP22 was in production at that time. I found an article in Television Digest, May, 1954 talking about new RGB phosphors used in the forthcoming RCA19 inch CRT(cancelled) principally to increase persistence time.

[etype2]

Originally Posted by old_tv_nut

Edit: is it possible this comment refers to experimental tubes that preceded the production version of the 15GP22?
I have read that some early prototype tubes had a red phosphor that required using a color filter over the face, making for a really dim picture; not sure about the persistence.

To follow up, I read about the proposed RCA 19 inch color tube in 1954 that (was cancelled because of the 19 inch CBS COLORTRON,) changed the red phosphor to a short persistence zinc selenide formulation and the green and blue phosphors were also changed principally for improved efficiency and balance. Source, Tele-Tech April, 1954.

[jhalphen]

Hi to all,

Evolution of color CRT phosphors in Wikipedia article :

"The red phosphor saw the most changes; it was originally manganese-activated zinc phosphate, then a silver-activated cadmium-zinc sulfide, then the europium(III) activated phosphors appeared; first in an yttrium vanadate matrix, then in yttrium oxide and currently in yttrium oxysulfide. The evolution of the phosphors was therefore (ordered by B-G-R):"

Blue--------Green-----------Red
ZnS:Ag – Zn2SiO4:Mn – Zn3(PO4)2:Mn
ZnS:Ag – (Zn,Cd)S:Ag – (Zn,Cd)S:Ag
ZnS:Ag – (Zn,Cd)S:Ag – YVO4:Eu3+ (1964–?)
ZnS:Ag – (Zn,Cd)S:Cu,Al – Y2O2S:Eu3+ or Y2O3:Eu3+
ZnS:Ag – ZnS:Cu,Al or ZnS:Au,Cu,Al – Y2O2S:Eu3+

article is here:
https://en.wikipedia.org/wiki/Phosphor

Europium doping was a game changer finally allowing equivalent drive & beam currents on all 3 guns.
developed by Sylvania if i recall correctly. June 1964 announcement by Sylvania in Electronics World :
https://schematicsforfree.com/files/...TV%20Tubes.pdf

for pure CRT enjoyment, read "The Cathode Ray Tube" by Peter A Keller, THE definitive publication on the subject.
download pdf here, 330 pages, 50Mb :
https://docs.ampnuts.ru/eevblog.docs...athode-ray.pdf

Merry Christmas to all !

Best Regards
jhalphen
Paris/France

Sylvania 1964 advert for ColorBright-85 CRT: