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  #31  
Old 12-15-2008, 03:20 AM
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I read your interesting discussions about the topic. I want to clarify that my comments were referring to the systems at the beginning, and no subsequent improvements. performed over time.
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  #32  
Old 12-16-2008, 07:11 PM
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Quote:
Originally Posted by firenzeprima View Post
I read your interesting discussions about the topic. I want to clarify that my comments were referring to the systems at the beginning, and no subsequent improvements. performed over time.
There's a lot of false information floating around. And there's always this undercurrent of television standard nationalism that sort of gets in the way of these discussions. Its always good to remember that these television standards were the best B&W standards the 1930's could provide. And that when color was added, they became the best the 1950's could provide.

PAL & SECAM were developed by learning the lessons that NTSC provided. They tackle similar problems in different ways.

The problem is that over the years so much ground has been covered with the improvement of the various systems, that its hard to really look back and see what the original problems were.

For example, you mentioned saturation problems. The question is, were they really problems with the NTSC standard, or were they problems with the vacuum tube (valve) technology of the time? If so, did those problems supposedly corrected by PAL & SECAM suddenly disappear once the technology shifted to solid state? If so, then it wasn't a problem in the standard, but in the implementation.

I'd be curious though to read more about the problems you describe. I know that especially in the early days no one had a good idea how to correctly setup color systems. ABC TV here in the states didn't even use vectorscopes for color setup. All of the color setup and testing procedures were developed over a long period of time, and often through experimentation.

David
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  #33  
Old 12-16-2008, 08:44 PM
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Going back on topic to the color variations in NTSC. I think I might have found at least a source that may answer some of our questions about early NTSC. The BBC launched a trial of NTSC on their 405line system. Although I haven't had a chance to read all the way through, they are likely to give the good and the bad about NTSC in their report. I post it here for all to consider:

http://www.bbc.co.uk/rd/pubs/archive...nograph_18.pdf

As I said. I don't know if the answer is there, I haven't read it all the way through yet (its pretty technical). But, it should be a good read for this subject.

David

Last edited by dtuomi; 12-16-2008 at 08:44 PM. Reason: Spelling
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  #34  
Old 12-17-2008, 09:52 AM
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the news that I reported here are from technical reports on the comparison between different systems. not personal opinions.
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  #35  
Old 12-17-2008, 06:37 PM
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Quote:
Originally Posted by firenzeprima View Post
the news that I reported here are from technical reports on the comparison between different systems. not personal opinions.
I have no doubts about that. Unfortunately, I'm not able to find the particular problem we've been discussing. I finally slogged through the BBC report above, and it didn't mention the kind of problems you were describing. It's definitely worth a look, even if its just to see the BBC's version of the Triniscope television.

David
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  #36  
Old 12-17-2008, 10:37 PM
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Quote:
Originally Posted by dtuomi View Post
Going back on topic to the color variations in NTSC. I think I might have found at least a source that may answer some of our questions about early NTSC. The BBC launched a trial of NTSC on their 405line system. Although I haven't had a chance to read all the way through, they are likely to give the good and the bad about NTSC in their report. I post it here for all to consider:

http://www.bbc.co.uk/rd/pubs/archive...nograph_18.pdf

As I said. I don't know if the answer is there, I haven't read it all the way through yet (its pretty technical). But, it should be a good read for this subject.


David

Thanks! i have not seen a copy before - now to read. read, read...
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  #37  
Old 12-19-2008, 02:32 PM
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Zenith

Zenith also made tv specifically made for Pal B/G 625 lines. This is my Zenith hybrid tv. Not modified nor "assembled in Italy". Just a Zenith Pal tv.
In my opinion Secam tends to develop a kind of bluish smear on some color areas and this is noticeable with my old hybrid french tvs as with the newest ones. I once had the chance to watch a football match broadcasted in NTSC M with a RCA solid state 19" tv and the colors were simply superb! I never saw anything similar on any Pal tv. I don't think matter of color accuracy is so important. I think is what please the most the viewer's eyes is what really counts! Color perception varies from one subject to another. I met people who thought they had perfect pictures on their tvs which were instead quite far from color perfection (reddish or bluish or greenish whites, colored blacks etc...). Isn't pleasing watching an old english film and see red telephone cabins displayed in vivid red? Not very similar to reality but undoubtedly nice...
My two cents...
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  #38  
Old 12-19-2008, 03:02 PM
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yes, but remember that this was not to compare the various systems after the changes made over time. I was referring to the systems compared to their first debut on the market, ntsc was especially infamous for the instability of the stage, the SECAM is famous for the color red tomato, the pal had no major problems as was the synthesis of earlier systems with the elimination of these defects first.
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  #39  
Old 12-19-2008, 07:57 PM
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Quote:
Originally Posted by firenzeprima View Post
yes, but remember that this was not to compare the various systems after the changes made over time. I was referring to the systems compared to their first debut on the market, ntsc was especially infamous for the instability of the stage, the SECAM is famous for the color red tomato, the pal had no major problems as was the synthesis of earlier systems with the elimination of these defects first.
NTSC had mostly phase problems, I haven't been able to find references to problems with color intensity, purity, or RGB recovery. In fact the BBC report above listed those factors as being excellent in the NTSC system they were testing and that by and large the system was stable. They did have registration problems, but mostly they attributed that to the equipment in use.

So I've not yet found the exact problems you describe.

David

Last edited by dtuomi; 12-19-2008 at 08:00 PM. Reason: I talk too much
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  #40  
Old 12-22-2008, 01:08 PM
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One thing I notice after 39 years of watching NTSC color:

When my parents got our RCA CTC-38 (1969), the color was usually good at one "right" hue (phase) setting, yet it was not very uncommon (especially on videotaped network programming) for the phase to be far off the mark (green or purple faces, blue grass). Sometimes the local station would super a notice "technical difficulties" at the bottom. I understand this was because the NTSC reference signal ("back porch", "color burst") could not be transmitted with the picture on the microwave links then in use by networks (please, someone, tell me WHY this was so, if they can send a chartreuse dress image on the link, they can send the burst, can't they ?).
By about 1980, these "off-phase" events became very rare, so an NTSC-country TV viewer can set the "TINT" function just once and leave it alone. (this is now usually an item on the on-screen-display, like the "BRIGHT" or "CONTRAST" functions I assume are on the OSD menus of PAL and SECAM sets as well as NTSC)
I can only think of three reasons I adjust the hue. (1) one of my VCRs has it's own phase, red shows a little orange if I do not adjust it back to red. (2) one low-power station, on a near-zero budget (same as the old VCR). (3) My daughter is quite amused when I change Bob the Tomato into a giant grape!
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  #41  
Old 12-22-2008, 02:30 PM
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Quote:
Originally Posted by Robert Grant View Post
Trade barriers and field rate issues aside, don't ignore another very obvious reason European nations only adopted color TV later than the Americans did. Economics.

When NTSC color was introduced, Europe had not yet fully recovered from the immense tragedy of World War II, which left many of it's factories and research labs in ruin.

It would take some time before the economies of Western Europe would grow again. While the Americans were putting out millions of new overhead-valve cars, the European industrial economy was being driven by motorcycle production. Even the rise of the automotive mass-production age in Europe, circa 1958, was with subcompact cars, often featuring two-stroke engines with less than one-fifth the horsepower of the V-8 Chevys in America. Not until the 1970's would the purchasing power of the average European be compared to that of people in the USA or Canada.

One could also argue that Europe was not really as far behind as the introductory dates would suggest. Sure, NTSC color transmissions began in 1953, but color TV in the USA would be hampered the "chicken and egg" problem (people not buying color TV because most shows were monochrome, TV stations/networks not investing in color because very few people had color TV sets). Sales of color TV sets in USA actually -fell- between 1956 and 1960! The jam would not break until late 1965. Compare this with the UK. When BBC1 and ITN flipped the switch (15 November 1969), the market was ready-made, colour tellies - and colour programmes, were the usual quite quickly. Thus the real lag period (color America and monochrome Europe), only lasted about 5 years.

Two other things to add:
Field rate issues did not doom NTSC in Europe - there were forms of NTSC designed to work with a 50Hz field rate and a wider channel for overseas markets (much as Brazil uses PAL-M, a version of PAL for a 6MHz channel and 60Hz field rate)

I would be very interested to know how the proposed Italian "ISA-identification in alternate suppression" system worked.

Rob
I know what they say about the issues related to the choice between different systems in Europe and in this case in Italy, which were discussed in this forum. however RAI began with NTSC to make the first experimentation but was affected by various problems and therefore was immediately abandoned in favor of the other systems (PAL and SECAM). To learn more sull'ISA type "ISA Indesit" and then clik on "The War of color TV." you'll find some information, but few are able to learn more.
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  #42  
Old 12-22-2008, 03:38 PM
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Quote:
Originally Posted by Robert Grant View Post
One thing I notice after 39 years of watching NTSC color:

When my parents got our RCA CTC-38 (1969), the color was usually good at one "right" hue (phase) setting, yet it was not very uncommon (especially on videotaped network programming) for the phase to be far off the mark (green or purple faces, blue grass). Sometimes the local station would super a notice "technical difficulties" at the bottom. I understand this was because the NTSC reference signal ("back porch", "color burst") could not be transmitted with the picture on the microwave links then in use by networks (please, someone, tell me WHY this was so, if they can send a chartreuse dress image on the link, they can send the burst, can't they ?).
The burst was and is always transmitted with an analog signal. It must be, otherwise there is no color frequency and phase reference. However, it has been the practice frmm the beginning to generate a new, clean synchronizing and burst signal locked to the incoming signal. Early in the color days, there was often considerable degradation of the video and the burst, so when the burst was regenerated, sometimes it was the wrong phase. (Sometimes this was simply because no-one adjusted it correctly.) Since there might be more than one stage of regeneration, it could be very difficult to track down the stages at which something went wrong.

For a short time, a signal called VIR (vertical interval reference) was implemented. The idea was that this auxiliary burst would be inserted at the studio and not adjusted or replaced along the network. Some TV sets (General Electric in particular) used the VIR to make automatic color adjustments. However, broadcasters discovered that they could use the VIR to adjust the signal and even automatically compensate any transmitter shortcomings. At that point, the VIR was being adjusted and no longer represented the original studio signal. Eventually, the industry gave up on the whole idea.

Improvements were made in the networks over the years. At one time, the networks adopted atomic clocks to set the burst frequency, and the local stations then locked to that. Later, when frame synchronizers became available, the local stations could re-sync all incoming signals to their local reference.

Another big improvment was simply the move to solid state gear, which could go much longer than tube gear without drifting out of specification.


These days, with much video being originated in digital components, or at least converted to digital before going over the network, there are fewer points at which it is critical to carry the burst properly.
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