Editing List of BBC test cards (section)

==Test Card C==
[[File:Testcard c.jpg|thumb|upright=0.8|Test Card C]]
Test Card C<ref>{{Cite web|url=https://www.flickr.com/photos/tim_anderson/27707084490/|title=Test Card C BBC|date=July 16, 2015|via=Flickr}}</ref> was a BBC television test card first broadcast in 1947.<ref name=":1" /> It was the first test card to resemble the famous Test Card F.<ref name="meldrum"/> 

Test Card C allowed adjustment and verification of parameters such as:<ref name=":3">{{Cite web |last=Pemberton |first=Alan |date=2016-03-03 |title=Not just a pretty face... Technical descriptions of UK test cards |url=http://www.pembers.freeserve.co.uk/Test-Cards/Test-Card-Technical.html |access-date=2024-11-05 |website=Pembers' Ponderings |archive-date=3 March 2016 |archive-url=https://web.archive.org/web/20160303165836/http://www.pembers.freeserve.co.uk/Test-Cards/Test-Card-Technical.html |url-status=bot: unknown }}</ref>

* Aspect Ratio: central circles

* Resolution: five gratings corresponding to frequencies of 1.0, 1.5, 2.0, 2.5 and 3.0 MHz
* Contrast: five steps with the top square corresponding to 100% and the bottom square to 30% luminance
* Linearity: white squares 
* Low Frequency Response: letterbox above the circle
* Reflections: black and white areas to the sides of the circle
* Focus: diagonal black and white stripes
* Picture into sync: triggered by the castellations 

The card was available as individual rolls of [[test film]] in the UK and many [[Member states of the Commonwealth of Nations|Commonwealth countries]] up until the end of the black-and-white television era.<ref>{{cite web |date=28 March 2015 |title=BBC Testcard C Telecine Lineup 16mm Film Loop |url=https://www.youtube.com/watch?v=W0FyGTg1Abg |website=[[YouTube]]}}</ref><ref>{{cite web |date=13 December 2014 |title=Telecine - a brief guide |url=https://www.youtube.com/watch?v=jGLZ3ru3N5k |website=[[YouTube]]}}</ref>

Test Card C continued in use on 405-lines until 1964 being replaced by Test Card D.<ref name=":3" />

625-line variants of Test Card C were later used in [[Jamaica]], [[Mauritius]], [[Singapore]] and [[Trinidad and Tobago]]. Heavy modifications of Test Card C were used by [[ABC Television (Australian TV network)|ABC Television]] in Australia<ref>{{cite web |title=Other 4:3 Testcards &#124; TVARK |url=https://tvark.org/features/testcards/other-4x3-testcards}}</ref> and [[National Iranian Radio and Television|NIRT]] in Iran.<ref>{{cite web |date=September 1977 |title=Television Servicing |url=https://worldradiohistory.com/UK/Practical-Television/70s/Television-Servicing-UK-1977-12.pdf |accessdate=17 April 2024 |page=44}}</ref>

=== Pye Test Card G ===
[[File:MonoscopeCU.jpg|thumb|Pye Test Card G as seen on a [[monoscope]].]]
[[Pye Ltd.|Pye]] developed a monochrome variant of Test Card C called Test Card G.<ref name=":1" /> It was used in several countries that use 625-line [[PAL]] and [[SECAM]], such as [[People's Republic of Bulgaria]],<ref>{{Cite web |date=2019-06-07 |title=Non-UK Television Test Cards, Tuning Signals, Clocks and Idents - Bulgaria |url=http://www.radios-tv.co.uk/Pembers/Test-Cards/Non-UK.html#Bulgaria |archive-url=https://web.archive.org/web/20190607162532/http://www.radios-tv.co.uk/Pembers/Test-Cards/Non-UK.html#Bulgaria |archive-date=7 June 2019 |access-date=2023-01-13}}</ref> [[Denmark]],<ref>{{Cite web |date=2019-06-07 |title=Non-UK Television Test Cards, Tuning Signals, Clocks and Idents - Denmark |url=http://www.radios-tv.co.uk/Pembers/Test-Cards/Non-UK.html#Denmark |archive-url=https://web.archive.org/web/20190607162532/http://www.radios-tv.co.uk/Pembers/Test-Cards/Non-UK.html#Denmark |archive-date=7 June 2019 |access-date=2023-01-13}}</ref> [[Luxembourg]],<ref>{{Cite web |last=Kemp |first=AUTHOR: D. |title=How to receive Continental television |url=https://transdiffusion.org/2018/09/10/how-to-receive-continental-television/ |access-date=2023-01-13 |website=Transdiffusion |language=en-GB}}</ref> [[Thailand]], [[Barbados]], [[Malaysia]],<ref>{{Cite web |last=Mann |first=Anthony |date=2005-03-21 |title=TV Malaysia received in Perth, Western Australia 1975-1987 |url=http://internal.physics.uwa.edu.au/~agm/tvphotos/rtm.html |archive-url=https://web.archive.org/web/20050321175707/http://internal.physics.uwa.edu.au/~agm/tvphotos/rtm.html |archive-date=21 March 2005 |access-date=2023-01-13 |website=Anthony (Tony) Mann's TVDX page}}</ref> and [[Hungarian People's Republic]],<ref>{{cite web |title=Hungarian ETC's |url=https://ing-sat.hu/hun-monoszkop.htm}}</ref> but not in Britain.<ref name="meldrum" /> A slightly modified version was used by [[YLE]] in [[Finland]] until it switched to the colour [[Telefunken FuBK]] test card in the 1970s, as well as in [[Norway]] where [[NRK]] and [[Telenor]] used it in conjunction with the [[EIA 1956 resolution chart]] until it switched to the Philips PM5544, Test Card F and the Telefunken FuBK test cards in the 1970s.<ref>{{Cite web |date=15 February 2020 |title=Vintage Electronics Blog & Forum - Radios, Television, Hi-Fi |url=http://www.radios-tv.co.uk/Pembers/Test-Cards/Non-UK.html |access-date=6 September 2017 |archive-date=7 June 2019 |archive-url=https://web.archive.org/web/20190607162532/http://www.radios-tv.co.uk/Pembers/Test-Cards/Non-UK.html |url-status=dead }}</ref>