Editing Indian-head test pattern

{{Short description|Television test card}}
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[[File:RCA Indian Head Test Pattern.svg|thumb|right|312px|The RCA Indian-head test pattern]]

The '''Indian-head test pattern''' is a [[test card]] that gained widespread adoption during the [[History of television#Electronic television|black-and-white television]] broadcasting era as an aid in the calibration of [[television]] equipment. It features a drawing of a [[Native Americans in the United States|Native American]] wearing a [[War bonnet|headdress]] surrounded by numerous graphic elements designed to test different aspects of broadcast display. The card was created by [[RCA]] to be the standard image for their TK-1 [[monoscope]], a simple [[video camera]] capable of producing only the image embedded within it. The pattern was introduced in 1939 and over the following two decades became a fixture of television broadcast across North America in [[525-line]] resolution and (often in modified form) abroad in 525- and [[625-line]] resolution until it was made obsolete by the rise of [[color television]] in the 1960s.

== Features and use ==
[[File:Radio TV News Jan 1949 pg38.jpg|thumb|The Indian Head pattern as mentioned in [[Ziff Davis]]'s ''Radio & Television News'' trade magazine in January 1949.]]
[[Image:Indian Head Test Pattern with Labels.png|thumb|upright=2|Indian Head pattern with its elements labeled, describing the use of each element in aligning a black and white analog TV receiver.]]

The Indian-head test pattern was created by [[RCA]] at their factory in [[Harrison, New Jersey]]. Each element of the card was designed to measure a specific technical aspect of television broadcast so that an experienced engineer could, at a glance, identify problems. The card contains elements used to measure aspect ratio,{{efn|[[Analog television]] on [[cathode-ray tube]]s also needed to be adjusted for vertical and horizontal linearity. An error in vertical linearity (such as the top of the picture stretched with the bottom squashed) might go unnoticed on the SMPTE colour bar pattern, but would instantly turn a circle into an egg-shape.}} perspective, framing, linearity, frequency response, differential gain, contrast, and brightness. The grid and circles were used for perspective, framing and linearity. The tapered lines (marked with 20, 25, 30, and 35) were used for resolution and frequency response. The thin lines marked from 575 to 325 on one side and 300 to 50 on the other side referred to lines of resolution. The gray bands emerging from the center off to the lower right and upper left were for differential gain, contrast, and white level.

The pattern began with the Indian-head portrait created in August 1938 by an artist named Brooks using pencil, charcoal, ink and [[zinc oxide]].<ref name="Pharis" /> For about a year, the portrait (which contains several identifiable shades of gray from [[Zone System|Zone VIII]] texture in the white feathers to [[Zone System|Zone II]] texture in the black hair) was the entire test pattern, but in 1939 the portrait was incorporated into the current pattern of calibrated lines and shapes.

[[File:RCA TK-1C.jpg|thumb|The RCA TK-1C monoscope camera that generated the test pattern]]Television stations would produce the image of the Indian-head test pattern in two ways. First, they would use a [[monoscope]] in which the pattern was permanently embedded, which was capable of producing the image with a high degree of consistency due to the device's simplicity. The monoscope tube is constructed similarly to a small [[cathode-ray tube]] (CRT), but instead of displaying an image, it scans a built-in image, producing a video signal. The tube has a perfectly proportioned copy of the test pattern master art (or a modified variant with the station ID replacing the Indian-head portrait, such as those used by [[KDFW|KRLD-TV]],<ref>{{cite web | url=https://www.earlytelevision.org/rca_tk1c.html | title=RCA TK-1C Monoscope}}</ref> [[KXAS-TV|WBAP-TV]]<ref>{{cite web | url=https://digital.library.unt.edu/ark:/67531/metadc1337921/ | title=&#91;WBAP-TV Test Pattern&#93; | date=1965}}</ref> and [[KFOR-TV|WKY-TV]]<ref>{{cite web | url=https://www.tahlequahdailypress.com/news/tv-transformative-for-tahlequah-residents/article_1f190770-f861-5b79-a644-f025201f2e64.html | title=TV transformative for Tahlequah residents | date=8 October 2016}}</ref>) inside, permanently deposited as a carbon image on an aluminum target plate or slide. The target plate is sequentially scanned with a focused beam of electrons, which were originally called ''[[cathode rays]]''. When the electron beam strikes the carbon image areas, the carbon resists current flow, and the resulting lower electron current flow is adjusted to appear as video black. When the electron beam strikes the metallic-aluminum image areas, there is less resistance with higher current flow, and the resulting higher electron current flow is adjusted to appear as video white. This image was used to calibrate monitors in the station. Second, stations would use a cardboard-mounted lithograph of the test pattern (typically attached to a rolling easel in each TV studio); videographing the lithograph would create a second image that could be compared against the monoscope-created control image.

The test pattern was useful for the calibration of home television sets as well as television studio equipment, so the image was routinely broadcast outside hours of [[Broadcast programming|programming]].<ref name="RTVN1949">{{cite journal | last = Kay | first = M. S. |url=https://commons.wikimedia.org/wiki/File:Radio_TV_News_Jan_1949_pg38.jpg |title=The Television Test Pattern | journal = Radio & Television News | volume = 41 | issue = 1 | pages =38–39, 135–136 | publisher = Ziff-Davis |date=January 1949 |format=scan |via=Wikimedia}} "Every television station, prior to its actual broadcasting period, transmits a test pattern for the purpose of permitting set owners to adjust their receiver controls for optimum reception." The article also states that [[television program]]ming (in 1949) was only a few hours each evening. The Indian-head test pattern was built into the RCA "monoscope" tube, a 2F21, which acted as a complete replacement for the TV camera.</ref> (It was often accompanied by an audio test tone for the purposes of calibrating aural system frequency response measurements.<ref>1,000 Hz is the standard 0dB (0 [[decibel]]) reference point for analog-NTSC TV aural system frequency response measurements, but for simple line-reference 0dB audio level setting, preference for hearing 400 Hz is common knowledge and experience among broadcast and audio technicians. "From the factory the frequency of the reference tone is configured to be 400 Hz. This is a nice alternative to the more typical 1 kHz, a frequency which can soon become very annoying to a listener's ears. In most cases 400 Hz will be perfectly acceptable, and actually preferred." - [http://www.studio-tech.com/PDFFiles/M742ug_2.pdf Model 742 Audio Mixer User Guide, Issue 2, May 2005 (PDF)] {{webarchive|url=https://web.archive.org/web/20061217022352/http://www.studio-tech.com/PDFFiles/M742ug_2.pdf |date=2006-12-17}}; p.10 - Studio Technologies, Inc.</ref>)

== As a cultural icon ==
From the late 1950s the test pattern gradually began to be seen less frequently, after fewer sign-offs, on fewer stations, and for shorter periods in the morning, since new and improved TV broadcast equipment required less adjusting. In later years the test pattern was transmitted for as little as a minute after sign-off while the transmitter engineer logged required [[Federal Communications Commission]]-US/[[Board of Broadcast Governors]] transmitter readings before cutting power.{{Citation needed|date=January 2010}}

The Indian-head test pattern became obsolete in the 1960s with the debut of [[color television]]; from that point onward, an alternate test card of [[SMPTE color bars]] (and its immediate predecessors), or colorized versions of the NBC/CBS-derived "bullseye" patterns became the test card of choice. Since the 1990s, most television stations in the [[United States]] have broadcast continuously without regular sign-offs, instead running [[infomercial]]s, networked overnight news shows, syndicated reruns, cartoons, or old movies; thus, the broadcast of test patterns has become mostly obsolete (though they are still used in post-production and broadcast facilities to check color and signal paths).

Nevertheless, the Indian-head test pattern persists as a symbol of early television. Many U.S. television stations chose the image of the Indian-head card to be their final image broadcast when their analog signals signed off for the final time between February 17 and June 12, 2009, as part of the [[digital television transition in the United States]].<ref>{{cite web | url=https://www.youtube.com/watch?v=NxnDrgbrMj0&list=WL&index=6 | title=Historic WLWT-TV Turns off Analog Signal | website=[[YouTube]]| date=15 June 2009 }}</ref><ref>{{Citation |title=WMTV 2009 analog sign-off | date=16 July 2013 |url=https://www.youtube.com/watch?v=F4LTk3CNHEI |access-date=2023-06-28}}</ref>{{Unreliable source?|date=August 2024}}<ref>{{cite web | url=https://www.youtube.com/watch?v=gVEQiSuEhmg | title=MPT Analog signoff | website=[[YouTube]] | date=17 November 2022 }}</ref>{{Unreliable source?|date=August 2024}}

A variant of the card appeared on the Canadian sketch comedy show [[Second City Television]] in the late-1970s,<ref>{{cite web | url=https://www.youtube.com/watch?v=wZSwYEqL738 | title=SCTV - Second City Television - "Lust for Paint" - WMAQ-TV (Complete Broadcast, 8/20/1978) 📺 | website=[[YouTube]] | date=28 March 2019 }}</ref> and another variant appeared on theatrical release posters for [["Weird Al" Yankovic]]'s 1989 film ''[[UHF (film)|UHF]]''. Some [[Pioneer Corporation|Pioneer]] GGV1069 [[LaserDisc]] reference discs released for the NTSC market included a variant of the card, but modified with a gray-colored grid and a drawing of a [[Komainu|Japanese lion-dog]] replacing the Indian-head portrait.<ref>{{cite web | url=https://originaltrilogy.com/topic/Laserdisc-players-screenshot-comparison/id/12907/page/2 | title=Laserdisc players - screenshot comparison - Original Trilogy }}</ref><ref>{{cite web|url=http://www.meldrum.co.uk/mhp/feedback.html|title=A selection of comments and suggestions received using the Feedback form or direct via email|work=meldrum.co.uk|accessdate=2015-06-07}}</ref> It was sold as a night-light from 1997 to 2005 by the [[Archie McPhee]] company,<ref>The Indian-head test pattern night light was included in a set of three novelty night lights with test pattern lamp shades: RCA TK-1 Indian head (1950s), SMPTE color bars (1960s), and an [[Emergency Broadcast System]] (EBS) TV-test slide image ("This is a test! This is only a test!") from the middle [[Cold War]] era.According to the customer service department of Archie McPhee company, Seattle, Washington, the set of three, as Item #10480, was sold from 1999-01-11 to 2005-06-17. Their representative said these lamp shades were created by the company, and not obtained from an outside source. (Source accessed by phone on 2007-11-07).{{original research inline|date=August 2017}}</ref> reminiscent of the times when a fairly common late-night experience was to fall asleep while watching the late movie, only to awaken to the characteristic sine wave tone accompanying the Indian-head test pattern on a black-and-white TV screen. The test card also featured in the opening sequence of the early 1960s science fiction anthology ''[[The Outer Limits (1963 TV series)|The Outer Limits]]''.<ref>{{cite web|url=https://www.youtube.com/watch?v=8CtjhWhw2I8 |archive-url=https://ghostarchive.org/varchive/youtube/20211222/8CtjhWhw2I8 |archive-date=2021-12-22 |url-status=live|title=The Outer Limits Intro|last=chicagosundials|date=19 November 2008|via=YouTube}}{{cbignore}}</ref> It also features as a loading screen in the [[Fallout (franchise)|Fallout]] franchise.<ref>{{cite news |url=https://mashable.com/article/fallout-easter-egg-please-stand-by |title='Fallout' hides a neat game loading screen Easter egg in episode 1 |author=Shannon Connellan |date=2024-04-13 |publisher=Mashable }}</ref>

===Artifacts===
Nearly all of the hard-to-open, steel-shielded monoscope tubes were junked with their Indian-head test pattern target plates still inside, but many of the board-mounted lithographs survive.

The master art for both the portrait and the pattern design was discovered in a dumpster by a wrecking crew worker as the old RCA factory in [[Harrison, New Jersey]] was being demolished in 1970. The worker kept the art for over 30 years before selling it to a collector.<ref name="Pharis">{{cite web|url=http://www.pharis-video.com/p4788.htm|title=Chuck Pharis Web Page : The Indian Head Test Pattern Story! , Updated April 29, 2017|website=www.pharis-video.com}}</ref>

== International variants ==
[[File:Pattern extracted from a physical PM5644.png|thumb|4:3 monochrome pattern resembling the RCA Indian-head extracted from a [[Philips PM5644]] [[Video signal generator|generator]] of likely European ([[PAL]]) origin.]]
The Indian head was also used by the [[Canadian Broadcasting Corporation]] (CBC)<ref>{{Cite web |date=22 April 2012 |title=CBC-TV Test Pattern Explained p12-13 |url=https://www.flickr.com/photos/jmv/7101326755}}</ref> in Canada in conjunction with its own monochrome test pattern,<ref>https://worldradiohistory.com/hd2/IDX-UK/Technology/Technology-All-Eras/Archive-Practical-Television-IDX/70s/Television-Servicing-UK-1974-02-OCR-Page-0033.pdf {{Bare URL PDF|date=August 2024}}</ref> following the [[O Canada|Canadian national anthem]] sign-off in the evening, and during its final years in the late-1970s and early-1980s it was shown before sign-on in the morning, after the showing of the [[SMPTE color bars]].<ref>{{cite web |last=MTLTV |date=28 September 2012 |title=Tête de l'indien |url=https://www.youtube.com/watch?v=VNHmA6VAD58 |url-status=live |archive-url=https://ghostarchive.org/varchive/youtube/20211222/VNHmA6VAD58 |archive-date=2021-12-22 |via=YouTube}}{{cbignore}}</ref>

In [[Thailand]] it was used by [[MCOT HD|Thai TV Channel 4]] when Thailand used the 525-line system.<ref>{{cite web |title=ขุดกรุ:จากสถานี HS1PJ ถึงโทรทัศน์สีสเตอริโอ |url=http://portal.rotfaithai.com/modules.php?name=Forums&file=viewtopic&p=11397 |language=th}}</ref>

It was also used by [[Zimbabwe Broadcasting Corporation|Rhodesia Television]] (RTV) during British colonial times (varying between [[Northern Rhodesia|Northern]] and [[Southern Rhodesia]]) following the playing of "[[God Save the Queen]]" at closedown.

This test pattern was later used by the Venezuelan TV channel [[Venevisión]], in conjunction with the [[Electronic Industries Alliance|RMA]] Resolution Chart 1946, until the late-1970s before signing on with the [[Gloria al Bravo Pueblo|Venezuelan national anthem]]. [[Telesistema Mexicano]] (now [[Televisa]]) stations also used this test pattern until the late-1960s immediately after playing the [[Himno Nacional Mexicano|Mexican national anthem]] at sign-off.

In the [[Dominican Republic]], the Indian-head pattern was used by its public broadcaster [[Corporación Estatal de Radio y Televisión]] (CERTV) in the late-1960s and 1970s (in conjunction with the [[EIA 1956 resolution chart]] test card) after playing the [[National Anthem of the Dominican Republic]] at sign-off.

[[File:Radio-Head-of-Gothenburg-Nils-Dahlbeck-Vintage-photo-352373202991.jpg|thumb|312px|Swedish botanist and radio and TV personality {{ill|Nils Dahlbeck|sv}} posing in front of the Indian-head test pattern and the [[Chalmers University of Technology]] experimental TV station test card<ref>{{cite web |title=I går syntes Kalle Anka på TV-skärmen och han hördes också. - PDF Free Download |url=https://docplayer.se/2897676-I-gar-syntes-kalle-anka-pa-tv-skarmen-och-han-hordes-ocksa.html}}</ref> in 1957]]
In [[Sweden]], the Indian-head test pattern was used in test transmissions from the [[KTH Royal Institute of Technology]]<ref>{{cite web | url=https://www.vlt.se/artikel/tv-sandningar-till-vattentornet | title=TV-sändningar till vattentornet! | date=12 February 2014 }}</ref> in Stockholm alongside the RMA Resolution Chart 1946, Telefunken T05 test card, as well as other experimental test cards from [[Televerket (Sweden)|Televerket]] and [[Chalmers University of Technology]] from 1948 until November 1958 when it was replaced by the Sveriges Radio TV (now [[Sveriges Television]]) test card.<ref>{{cite web |last=erikbe99 |date=9 July 2007 |title=Testbilder genom tiderna |url=https://www.youtube.com/watch?v=qiKczfO6iY8 |url-status=live |archive-url=https://ghostarchive.org/varchive/youtube/20211222/qiKczfO6iY8 |archive-date=2021-12-22 |via=YouTube}}{{cbignore}}</ref><ref>{{Cite web |year=1957 |title=Svenska: Radiochefen i Göteborg Nils Dahlbeck |url=https://commons.wikimedia.org/wiki/File:Radio-Head-of-Gothenburg-Nils-Dahlbeck-Vintage-photo-352373202991.jpg}}</ref>

In Australia, the Indian-head test pattern was used by [[TNT (Australian TV station)|TNT-9]] in Northern [[Tasmania]] in conjunction with the Marconi Resolution Chart No. 1 from its launch in 1962 until it adopted colour television in the mid-1970s. This version eschewed the Indian head drawing with the TNT-9 station ID on top, similar to the aforementioned KRLD-TV, WBAP-TV and WKY-TV variants.<ref>{{cite news |title=TNT9 helped north of state find its voice . . . and it was loud |url=https://www.examiner.com.au/story/7743900/tnt9-helped-north-of-state-find-its-voice-and-it-was-loud/ |access-date=2024-04-18 |work=The Examiner (Tasmania) |date=2022-05-18 |archive-url=https://web.archive.org/web/20230417061527/https://www.examiner.com.au/story/7743900/tnt9-helped-north-of-state-find-its-voice-and-it-was-loud/ |archive-date=2023-04-17}}</ref>

[[Saudi Broadcasting Authority]] in Saudi Arabia also formerly used a modified version of the Indian-head test pattern, with the [[Emblem of Saudi Arabia]] replacing the Indian head drawing,<ref>{{cite web |url=https://worldradiohistory.com/UK/Practical-Television/70s/Television-Servicing-UK-1977-12.pdf |title=Television Servicing |date=September 1977 |accessdate=17 April 2024 |page=44}}</ref><ref>Archived at [https://ghostarchive.org/varchive/youtube/20211205/OlGJ7EM5GpU Ghostarchive]{{cbignore}} and the [https://web.archive.org/web/20200418044526/https://www.youtube.com/watch?v=OlGJ7EM5GpU&gl=US&hl=en Wayback Machine]{{cbignore}}: {{cite web |title=saudi tv test pattern (1965) |url=https://www.youtube.com/watch?v=OlGJ7EM5GpU |website=[[YouTube]]| date=27 May 2014 }}{{cbignore}}</ref>{{Unreliable source?|date=August 2024}} from 1954 until 1982 when it was replaced with a heavily modified [[Philips PM5544]] test card.

The Indian head was also used in [[Brazil]] by [[Rede Tupi]], both as a test pattern and [[:File:Primeira Vinheta da TV Tupi 1950.ogg|as part of a television ident]], from its launch in 1950 until it became the first Brazilian television network to adopt colour television in 1971–72.

The Indian head pattern was also used by [[Kuwait Television]] in [[Kuwait]] from its launch of television services in 1961 until it adopted colour television in the mid-1970s.

In [[Italy]], the pattern was adapted and modified by [[RAI]] for its monochrome test cards, used from 1961 to 1977. There were two versions during most of its existence, one with a large N for [[Rai 1|Programma Nazionale]] and another with a large 2 for [[Rai 2|Secondo Programma]]. By 1976, the N was replaced by a 1 and was made smaller (the same happened to the second network's 2).<ref>{{Citation |last=Borgiatto |first=Gian Domenico |title=MONOSCOPIO RAI CANALE NAZIONALE |date=2013-06-09 |url=https://www.flickr.com/photos/94566993@N05/8996886385/ |access-date=2023-03-13}}</ref><ref>{{Cite web |title=Principali monoscopi storici della tv pubblica italiana |url=https://radiomarconi1895.altervista.org/marconi/primi_monoscopi_rai.html |access-date=2024-12-12 |website=radiomarconi1895.altervista.org}}</ref>

== Notes ==
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== References ==
{{reflist}}

== External links ==
*{{cite web|url=http://www.pharis-video.com/p4788.htm |title=The Indian Head Test Pattern original master art |access-date=May 18, 2006 |url-status=unfit |archive-url=https://web.archive.org/web/20150615014500/http://www.pharis-video.com/p4788.htm |archive-date=June 15, 2015}} – rescued from an RCA dumpster in 1970
*Picture and detailed description of an [http://www.pharis-video.com/p2794.htm RCA TK-1 test pattern generator (monoscope)]
* [https://web.archive.org/web/20160214122843/http://www.mire-project.com/index.php/index.php?lang=EN-en mire.project] – Street art work about test patterns

{{standard test item}}

[[Category:Telecommunications-related introductions in the 1930s]]
[[Category:1938 establishments in the United States]]
[[Category:American inventions]]
[[Category:History of broadcasting]]
[[Category:Interstitial television shows]]
[[Category:Native Americans in popular culture]]
[[Category:Television presentation]]
[[Category:Television terminology]]
[[Category:Test cards|Indian-head]]