Talk:Color television

Page contents not supported in other languages.
From Wikipedia, the free encyclopedia


Consistent spelling[edit]

Am I completely out of line here or would it be reasonable to keep the spelling of "color" consistent with the article title (aside from direct quotes, citations, and external links, of course)? We've got so many IP addresses whose sole contribution to Wikipedia consists of randomly inserting some "u"s here. Meanwhile, actual spelling and grammar errors, acceptable on neither side of the Atlantic, go unremarked. --19:15, 23 January 2009 (UTC)

I feel it should be colour. As people have spoken about the Americanization of wikipedia. The fact is that no other English-speaking country in the world (including Canada) spell it as color. It seems like it's spelled this way purely for the American users. You are half right. Yes it should be consistent, but it should keep the spelling of colour, not color. 60.224.160.185 (talk) 19:49, 27 May 2013 (UTC)[reply]

Wikipedia has a well-established policy about this: neither spelling is the "correct" one. If the article concerns something strongly associated with a country where one spelling prevails, then that spelling is used. In an article about Turner's paintings, or English heraldry, or autumnal foliage in Canada, it's "colour". Among English-speaking countries, the overwhelming majority of work on developing color TV was done in the US, and it was available in the US in 1954 while not introduced in the UK, Canada and Australia until circa 1967, so in this article the spelling is very justifiably "color". If there is no particular national association, then the spelling used when the article was founded is retained. The spelling should be consistent within the article unless there is a definite reason for using the alternative in some instances (proper names, etc). Much time and effort are wasted on Wikipedia by "drive-by" editors globally changing a spelling to what they "feel it should be", almost always soon to find that another editor, in keeping with the policy, has reverted their changes. Please don't add to this problem. AVarchaeologist (talk) 22:23, 1 September 2013 (UTC)[reply]

Wikipedia is headquartered in San Francisco, a majority of its servers are in the United States, and most of world's native English speakers use American English.71.209.198.57 (talk) 15:36, 20 July 2019 (UTC)[reply]

RGB[edit]

Initial trials of implementing color to television used the three primary colors (Red, Blue and Yellow) instead of the the RGB (Red, Green and Blue) format that soon took effect. The reason was the obvious theory that all colors spawn from primary colors. However, after the first test of the display it became apparent that this format would not work as it displayed colors horribly wrong. After replacing the color primary color yellow with the secondary color green it displayed correctly. I'm not 100% of the accuracy of this information, but I do know that the first color television tests were used with primary colors before they found out that yellow was causing displays with incorrect colors. I think this is an important part of the history section of Color Television and should be added. I haven't researched enough to find citations as I just stumbled onto this page. Also, I've never edited a wiki page before. I only wanted to bring this info to light so that the community could judge whether or not it is deemed appropriate. 64.207.245.230 (talk) 21:19, 22 January 2010 (UTC)[reply]

Coincidentally, I was reading yesterday about how James Clerk Maxwell was credited with creating the world's first color photograph in 1861, using the three additive primary colors of red, green, and blue. (ref) If Maxwell knew in 1861 that RGB constituted the appropriate primary colors to which the human eye responded for a full color image, surely color television engineers would have been aware of this in later years. Maxwell, incidentally, is credited as being the father of additive color. Wildbear (talk) 06:08, 23 January 2010 (UTC)[reply]
There are two different sets of primary colors: additive (RGB—red, green and blue) and subtractive (CMY—cyan, magenta and yellow, the complementary colors of red, green and blue; the traditional blue, red and yellow will work well enough with manual blending, but CMY is more flexible and can produce a much wider color gamut). They are two sides of the same coin. Additive color adds red, green and blue light to darkness to produce a wide range of colors, as well as grays and white. Subtractive color uses cyan, magenta and yellow dyes or pigments to control the amounts of red, green and blue light, respectively, that reach the eye by absorbing more or less of them from white light.
The main point of Maxwell's now-famous 1861 lecture was that additive color synthesis required a different set of primaries than the red, yellow and blue which centuries of experience with mixtures of pigments seemed to dictate.
Foredoomed attempts to use red, yellow and blue as additive primaries were made by some highly intelligent inventors in the fields of color photography and color television, so culturally ingrained was that ancient subtractive primary color set, but by the late 1920s the error, if they had ever been subject to it, had been left far behind by Baird, Jenkins and other well-known early workers in the development of television. AVarchaeologist (talk) 23:11, 1 September 2013 (UTC)[reply]

More than electronic versus mechanical[edit]

There were other issues that really ought to be reported on in order to make the history more complete. 1) The trade-off between making smaller picture details more finely defined, and on the other hand as a result, reducing the number of TV stations that can be on the air without causing mutual interference. This is a major conern of the FCC. At one point you wrote about the early version of the Y R-Y B-Y system using more spectrum space, which is true when compared to the mechanical color-wheel system, and you should find a source for that explicit explanation. The color-wheel system eventually satified the FCC (for a limited time), not because it reduced fine picture detail (which it did) but because it kept the same spectrum usage as the existing B&W system. 2) Under "Compatible Color" should be a more direct explanation of what the term means. It's only hinted here when you say it's very much like a B&W broadcast. More needs to be said. I refer you to sources in the popular press about RCA/NTSC color TVs being able to recieve B&W broadcasts for display in B&W, and B&W TVs being able to receive color broadcasts, also for display in B&W. 3) There was a period when color-wheel and all-electronics were competing for picture quality in demonstrations. You already mentioned that early on, color-wheel easily won. But later, after color-wheel was abandoned and the RCA system was further developed, the RCA system actually ended up with more human-visible picture definition than the CBS color-wheel system could theoretically and mathematically achieve, and at the same time also prevented the color-separation break-up problem inherent to the CBS system during live sports telecasts. 4) One of the big differences between RCA and CBS was initially mechanical versus electronic. But that difference actually disappeard when the shadow mask tube was demoed for the first time in 1950. The reason is that the shadow mask tube also works for the CBS system, a fact you can find, but with difficulty, making this a little-known fact. So from 1950 on, CBS was not inherently mechanical anymore. Granted, in 1950 the shadow mask tubes made bad pictures, making the press believe that the picture quality advantages of the CBS system could only be had with mechanical, and so in the press, CBS remained mechanical since that would be the version manufactured. But I mentioned inherently, and later on, if CBS was retained, it would probably use the shadow mask tube on the receivers. This is proven with a variant of the CBS system for NASA in the famous satelite launch video, which is viewed on shadow mask screens (on your TV at home and on your CRT computer), along with the inherent primary color break-up on the satelite edges as the satelite turns. This famous video is a good source for the article. Ghidoekjf (talk) 15:39, 13 February 2010 (UTC)[reply]

The NASA sequential color video being remembered above is, I suspect, actually of the 1972 lift-off from the moon of Apollo 17's Lunar Excursion Module, not the launch of a satellite. That bit of video captured mankind's final (to date) departure from the moon and is often included even in short retrospectives about the US space program. It provides an excellent demonstration of the big problem with any sequential field video (or motion picture) color system: stationary and slow-moving subjects may look just fine, but when anything has the audacity to move quickly, the resulting combined color image of it will at best show color fringes due to mismatch of the three color elements, and at worst show three completely separate spuriously colored images. Those bits of debris kicked up by the blast-off weren't really bright red, green and blue, of course, and watching sequential field color converted to the RCA format and displayed on a shadow mask CRT does nothing to put things right. NASA resorted to small black-and-white video cameras with spinning color wheels because three-pickup-tube color video cameras were too heavy, bulky and power-hungry to be acceptable for the purpose at hand. AVarchaeologist (talk) 08:57, 14 September 2013 (UTC)[reply]

RCA used Valensi's concept as the basis of all of their developments[edit]

Well, not for their early developments. There was a projection system using red, green and blue video signals, with only the green video full bandwidth on one assigned channel, the other two videos (red and blue) each with bandwidth cut in half so they can be shared on a second channel. This is not the Velensi concept. Also there is the early versions of RCA dot sequential. This system rapidly sampled R G B video from the studio and sent these in sequence over the air. With timing clock also sent over the air, the receiver separated out the original R G B video samples by rapid sampling and sending video samples to the corresponding primary color CRT of the projection system, or the appropirate gun in the shadow mask tube. While the total of the signal stream could be received on B&W sets to make it compatible, this in no way represented the color-difference scheme of Valensi's. The signals were R G B, not Y, R-Y, B-Y. With help from NTSC, this eventually grew into Valensi's Y R-Y B-Y. Ghidoekjf (talk) 15:39, 13 February 2010 (UTC)[reply]

Biased intro[edit]

It contains a long detailed paragraph about NTSC and TV in the US but only mentions PAL once "in passing". Roger (talk) 06:48, 31 July 2011 (UTC)[reply]

The hard reality is that while the UK can justly be proud of early milestones in television (Baird, the prewar BBC television service), PAL did not arrive on the scene until the US NTSC system had been up and running and becoming a fixture in US homes for a dozen years. The late finishers in a marathon, however fine or even superior their form, have to expect that the first-place runner who is already giving interviews when they enter the stadium will get the lion's share of the attention. AVarchaeologist (talk) 23:40, 1 September 2013 (UTC)[reply]
PAL compensates for unstable circuitry in receiving sets (simple tube-type circuits) by dramtically reducing the visual effect of hue errors on skin tones. By the way, many other colors are not so effectively corrected. PAL also compensates in this way for operator error inside the TV studio (especially where videotape is involved). This worked well enough that at least some (or maybe all) PAL receivers had no need of a Hue control, a major PAL advantage. But with solid state and better equipment, excessive studio adjustments have ceased, and TVs worked right out of the box, eliminating this PAL advantage over NTSC. So before about 2009, PALs advantage using the PAL technique over NTSC evaporated. But PAL had a con that NTSC does not have. For a given bandwidth, NTSC is more spectrum efficient than PAL because comb filters with 3-D motion compensaton are more effective with the 4-field cadence of NTSC than with the 8-field cadnece of PAL. The PAL developers might not have thought about this, since these kind of comb filters need IC's with digital processing of the analog signal. Ohgddfp (talk) 19:39, 20 February 2016 (UTC)[reply]
So maybe the intro is not so biased. After all, PAL is almost identical to NTSC, except for the phase alternate line technique used in PAL, and that PAL advantage over NTSC faded when equipment became more stable. So NTSC and PAL are really siblings technically. SECAM is really the odd man out. SECAM was magnificent when it came to video tape; no timebase correction needed for color reproduction. Also, SECAM does not require stable equipment to prevent hue errors of any kind. PAL only corrects some of the important colors in the face of unstable equipment. But SECAM is the most spectrum inefficient of all, with all kinds of flavors in different SECAM countries until they might have got it right. But it never was completely right; too much horizontal luminance detail had to be discarded, which in turn required TV channels with more bandwdith. And traditionally in the 1960's, SECAM and PAL were more complex to build than NTSC receivers Ohgddfp (talk) 19:48, 20 February 2016 (UTC)[reply]

RCA demonstrated their electronic color system on October 30, 1946[edit]

"RCA's demonstration of electronically produced color television at Princeton Wednesday (30) officially joined the long due battle over color tele standards. Battle to the end is now foreseen between black-and-whiters and RCA on one side, and CBS on the other, with the main joust centering on electronic versus mechanical systems." "CBS Sees Red at RCA Color". Billboard. 58 (45). Cincinnati Ohio: Billboard Publishing: pp. 12, 14. November 9, 1946. ISSN 0006-2510. {{cite journal}}: |pages= has extra text (help) --SWTPC6800 (talk) 19:07, 9 February 2012 (UTC)[reply]

It would perhaps be less misleading to say that "RCA demonstrated an electronic color system". There was no color picture tube, shadow-mask or otherwise, just three separate B&W tubes, their pictures combined by projection onto a screen through color filters. The RGB channels were full resolution, so triple the usual bandwidth was required. No actual color camera, just an electronic flying spot scanner with a 35 mm Kodachrome slide for subject matter. Yet another interesting but ultimately irrelevant technological dead end. AVarchaeologist (talk) 16:48, 2 September 2013 (UTC)[reply]

The dustbin of history[edit]

This article goes on and on about minute details of various analog color broadcasting technologies. but says little about the fact that they have been phased out in most developed countries and replaced by the far superior images provided by Digital television. That fact should be included in the lede, which still give the impression that analog color transmission is in wide use. Digital television says that The Netherlands changed over in 2006, the US in 2009 and that the last holdout, Costa Rica, is expected to switch in 2017. The NTSC and other systems still get some usage from the output of cable boxes and converters from antennas picking up digital signals and converting them to RF for an old TV. But most Wikipedia readers now have color TVs which do not function according to the technical principles described in this article. Don't present day digital television sets also qualify as "Color television," or is that term restricted to analog transmission? If this article is to discuss only analog color television broadcasting, then perhaps it should be moved to Analog color television. There is presently no information on the history of color broadcasting in the History of television article, just a pointer to this article. A brief summary of the development of color TV would improve that article (I removed a recent cut and paste from this article because it did not include wikilinks and references and did not provide attribution). Edison (talk) 15:38, 30 October 2013 (UTC)[reply]

This article still says "There are three main analog broadcast television systems in use around the world, PAL (Phase Alternating Line), NTSC (National Television System Committee) and SECAM (Séquentiel Couleur à Mémoire—Sequential Color with Memory). The system used in North America is NTSC. Western Europe, Australia, Africa and Eastern South America use PAL. Eastern Europe used SECAM, but switched to PAL after the change of the political regimes there. France still uses SECAM." Isn't that factually incorrect in October 2013? Edison (talk) 15:52, 30 October 2013 (UTC)[reply]
It is. With digital standards snapping at the heels of analogue systems, it would have made no sense to switch systems. Although you might regard this as original research, Russia was still using SECAM the last time that I was there in 2007, well after the communist regime fell. Fortunately, I have found a reference, so can correct the article. DieSwartzPunkt (talk) 17:22, 28 February 2015 (UTC)[reply]
About "But most Wikipedia readers now have color TVs which do not function according to the technical principles described in this article." Well, maybe as described in this particular article, so it should be therefore included. In any case, Internet video and Broadcast Digital TV actually does function according to many analog principles. 1) Valensi's concept. This is alive and well in Internet video, JPEG, MPEG, Digital cable, digital TV broadcast. This principle is the separation of chrominance (hue and saturation in the form of R-Y, B-Y) from luminance. 2) The lower resolution of the chrominance is also a trick that takes advantage of the limitations of the human eye in order to reduce bandwidth. This allows more simultaneous video streams for a given bandwidth, whether analog (more analog TV stations in the same geographical area) or digital (more simultaneous video streams). The MPEG-2 framework used in digital TV broadcast is set to 4:2:0 subsampling, where there is four times more luminance picture detail than chrominance detail. 3) Illusion of motion by rapidly displaying a series of still pictures. Analog systems and digital MPEG-2 based systems do this. 4) For each video frame, not the entire picture is sent at once. With digital MPEG-2, groups of pixels are sent, each group one after the other (cosine transform). With analog, each pixel is sent one after the other. For analog TV, this is in the form of a continuously changing value over the air, and is sometimes in the form of discrete time analog values (physcially individual pixels) for some kinds of analog TV studio equipment (bucket brigrade CCD analog delay lines for video tape timebase correction). 5) Interlace as used for digital television 1080i. For the same reasons in both analog and digital. Some digital TV receivers utilized 16:9 ratio cathode ray tubes (CRT's), which could display digital TV 1080i without having to perform the very difficult de-interlace calculations. But now CRT's are obsolete, and so now every digital TV must perform the de-interlace calculations (interlace to progressive scan conversion). But the interlace still retains the analog benefit of bandwidth reduction for both digital and analog, which is the real reason interlace was retained for 1080i digital TV. Ohgddfp (talk) 19:14, 20 February 2016 (UTC)[reply]

Development: Rods and Cones[edit]

About: "The human eye's detection system in the retina consists primarily of two types of light detectors, rod cells that capture light, dark, and shapes/figures, and the cone cells that detect color. A typical retina contains 120 million rods and 4.5 million to 6 million cones, which are divided among three groups that are sensitive to red, green, and blue light. This means that the eye has far more resolution in brightness, or "luminance", than in color." Ohgddfp (talk) 20:22, 20 February 2016 (UTC)[reply]

This above is actually misleading. On the surface, it seems logical that rods, being much more numerous than cones, and being only responsive to luminance would be the mechanisim to supply the perception of fine luminance detail. But I noticed on HyperPhysics, where this info could have been taken, also says the following - "The cones are responsible for all high resolution vision." This directly contradicts what is in this Wiki article. Hopefully someone will correct this soon. The reasoning is that while there are relatively few cones, they are packed extremely close together in the fovea where both luminance detail and color is perceived. So it's not the number of cones, but how closely they are packed in the portion of the eye where it counts. Also, in daylight, and also when viewing a screen, rods participate only very little. Ohgddfp (talk) 20:22, 20 February 2016 (UTC)[reply]

No. The cones have far less resolving power. If you create text of twice the size that can normally be read easily in black and white, but in two colours that have equal luminance, the text is impossible to read. Green and magenta work convincingly well in this regard even though the luminance of these two colours is not quite the same. 86.146.209.237 (talk) 17:18, 20 June 2020 (UTC)[reply]
Yes. (Sorry to disagree.) Cones have far greater resolving power. I already mentioned HyperPhysics before. Now also check out the Wikepedia article "Photoreceptor cell". Look at the section: "Difference between rods and cones". In the table, RODS: Low visual acuity, CONES: High visual acuity; better spatial resolution. Now I have provided 2 references that can be used in the article for this information. Ohgddfp (talk) 15:21, 24 June 2020 (UTC)[reply]

External links modified[edit]

Hello fellow Wikipedians, I have just modified 2 external links on Color television. Please take a moment to review my edit. If you have any questions, or need the bot to ignore the links, or the page altogether, please visit this simple FaQ for additional information. I made the following changes:

When you have finished reviewing my changes, please set the checked parameter below to true or failed to let others know (documentation at {{Sourcecheck}}). This message was posted before February 2018. After February 2018, "External links modified" talk page sections are no longer generated or monitored by InternetArchiveBot. No special action is required regarding these talk page notices, other than regular verification using the archive tool instructions below. Editors have permission to delete these "External links modified" talk page sections if they want to de-clutter talk pages, but see the RfC before doing mass systematic removals. This message is updated dynamically through the template {{source check}} (last update: 18 January 2022).

  • If you have discovered URLs which were erroneously considered dead by the bot, you can report them with this tool.
  • If you found an error with any archives or the URLs themselves, you can fix them with this tool.

Cheers.—InternetArchiveBot (Report bug) 04:47, 28 November 2016 (UTC)[reply]

External links modified[edit]

Hello fellow Wikipedians, I have just modified 2 external links on Color television. Please take a moment to review my edit. If you have any questions, or need the bot to ignore the links, or the page altogether, please visit this simple FaQ for additional information. I made the following changes:

When you have finished reviewing my changes, you may follow the instructions on the template below to fix any issues with the URLs. This message was posted before February 2018. After February 2018, "External links modified" talk page sections are no longer generated or monitored by InternetArchiveBot. No special action is required regarding these talk page notices, other than regular verification using the archive tool instructions below. Editors have permission to delete these "External links modified" talk page sections if they want to de-clutter talk pages, but see the RfC before doing mass systematic removals. This message is updated dynamically through the template {{source check}} (last update: 18 January 2022).

  • If you have discovered URLs which were erroneously considered dead by the bot, you can report them with this tool.
  • If you found an error with any archives or the URLs themselves, you can fix them with this tool.

Cheers.—InternetArchiveBot (Report bug) 16:21, 4 June 2017 (UTC)[reply]

External links modified[edit]

Hello fellow Wikipedians, I have just modified one external link on Color television. Please take a moment to review my edit. If you have any questions, or need the bot to ignore the links, or the page altogether, please visit this simple FaQ for additional information. I made the following changes:

When you have finished reviewing my changes, you may follow the instructions on the template below to fix any issues with the URLs. This message was posted before February 2018. After February 2018, "External links modified" talk page sections are no longer generated or monitored by InternetArchiveBot. No special action is required regarding these talk page notices, other than regular verification using the archive tool instructions below. Editors have permission to delete these "External links modified" talk page sections if they want to de-clutter talk pages, but see the RfC before doing mass systematic removals. This message is updated dynamically through the template {{source check}} (last update: 18 January 2022).

  • If you have discovered URLs which were erroneously considered dead by the bot, you can report them with this tool.
  • If you found an error with any archives or the URLs themselves, you can fix them with this tool.

Cheers.—InternetArchiveBot (Report bug) 21:53, 10 August 2017 (UTC)[reply]

Hoist "Color standards"[edit]

I think the (relatively brief) "Color standards" section should be hoist above the "Adoption" section. The "Adoption" section frequently mentions the different standards, which except (rightly) for brief mentions in the lede, are not explained while we dive into the details of which country or region adpoted which system. I have made a couple of mentions into links (to PAL, SECAM) in the "Adoption" section as in my opinion they are too far away from the links in the lede so deserve being linked again, they might be better de-linked if the order of the sections were swapped. 94.21.219.120 (talk) 04:19, 9 December 2018 (UTC)[reply]

Source on Belarus' colour TV broadcasts?[edit]

I've read that Belarus' Belteleradio was the first country in Europe to start regular colour broadcasts in 1961, but I have yet to see a credible source that actually states this. I'm thinking of removing this section, but if anyone has a valid source, please let me know. ThisIsMarvy TALK 19:26, 3 December 2020 (UTC)[reply]

Potential North Korea discrepancy[edit]

While doing research about SEK studios, I noted that one of their earlier animations, "Time Bomb" (1967) was produced in color, 7 years prior to the listed date on this page, I do not know if it was broadcasted in color at the time. This is the link to said animation, and looking at the logo in the top left, it seems to have been recorded from an actual North Korean broadcast, i'm just not sure when

(also my first Talk Page thing so I hope i'm doin aight Acedog11 (talk) 05:39, 5 September 2022 (UTC)[reply]