Test card
BBC test cards
Main article: List of BBC test cards
BBC test cards are identified by a letter. The most famous British test card is Test Card F which incorporates a colour photograph of Carole Hersee (daughter of BBC engineer George Hersee) playing noughts and crosses with a doll, used on the BBC and ITV from the beginning of colour broadcasts in the late 1960s. It was later updated as Test Card J, and for widescreen broadcasts as Test Card W. Test Card F has often been spoofed by comedians.
Decline
Formerly a common sight, test cards are now only rarely seen outside of television studios, post-production, and distribution facilities. In particular, they are no longer intended to assist viewers in calibration of television sets. Several things have led to their demise for this purpose:
Modern microcontroller-controlled analogue televisions rarely if ever need adjustment, so test cards are much less important than previously. Likewise, modern cameras and camcorders seldom need adjustment for technical accuracy, though they are often adjusted to compensate for scene light levels, and for various artistic effects.
Use of digital interconnect standards, such as CCIR 601 and SMPTE 292M, which operate without the non-linearities and other issues inherent to analogue broadcasting, do not introduce colour shifts or brightness changes; thus the requirement to detect and compensate for them using this reference signal has been virtually eliminated. (Compare with the obsolescence of stroboscopes as used to adjust the speed of record players). On the other hand, digital test signal generators do include test signals which are intended to stress the digital interface, and many sophisticated generators allow the insertion of jitter, bit errors, and other pathological conditions that can cause a digital interface to fail.
Likewise, use of digital broadcasting standards such as the DVB and ATSC eliminates the issues introduced by modulation and demodulation of analogue signals.
Test cards including large circles were used to confirm the linearity of the set’s deflection systems. As solid-state components replaced vacuum tubes in receiver deflection circuits, linearity adjustments were less frequently required (few newer sets have user-adjustable “VERT SIZE” and “VERT LIN” controls, for example). In LCD and other deflectionless displays, the linearity is a function of the display panel’s manufacturing quality; for the display to work, the tolerances will already be far tighter than human perception.
In developed countries such as the United States and the United Kingdom, the financial imperatives of commercial television broadcasting mean that air-time is now typically filled with programmes and commercials (such as infomercials) 24 hours a day, and non-commercial broadcasters have to match this.
In North America, most test cards such as the famous Indian Head test card of the 1950s and 1960s have long been relegated to history. The SMPTE color bars occasionally turn up, but with most North American broadcasters now following a 24-hour schedule, these too have become a rare sight. Many Canadian Broadcasting Corporation stations broadcast a modified form of the SMPTE bars (with an additional modulated ramp at the top and a CBC logo animation in place of the Q block) late at night until late 2006, when the network moved to 24-hour broadcasting.
When there are in fact no standard programmes being broadcast on the channels that do not have 24-hour programming, other, more informative features such as educational shows, e.g. the BBC Learning Zone, and teletext-type programmes such as Pages from Ceefax, ITV Nightscreen and 4-Tel On View are often broadcast, the latter type acting as the better test-card substitute as they just roll continuously.
Australian national broadcaster SBS airs a weather map in place of a test card with music from albums sold by SBS and a ticker at the bottom of the screen during the early hours of the morning.
Australian community broadcaster Channel 31 in Melbourne airs Fishcam, the output of a videocamera aimed at a fish tank.
Some Philippine cable networks replace test cards with an advertisement showing the product, “a reason to go to sleep” and the time when the station will sign on.
In Singapore, since 2004, instead of showing test cards, television channels usually air radio channels while showing their station ID at the same time.
In Thailand, Channel 5, Channel 9 and Channel 7 broadcast the advertising program (Innovations and Quantum Television) instead, Channel 7 does not broadcast Quantum Television whole night, after Quantum Television ran for 20 minutes and it is still being closing time, it will turn to the testcard, with royal anthem before switching. Channel owned by NBN (NBN1-4 and NTV) does not broadcast advertising programs since NBN refuse from broadcasting them. NBT and TVThai does not broadcast them either, because owned by government, but when TVThai still being ITV and TITV, it broadcast.
On television networks and stations in most of the Third World countries, test cards are still seen because most television networks and stations in those countries do not have 24-hour programming.
Use of test patterns and test cards is still common within television production facilities. Many of these still have analogue infrastructure, and currently as of March 2006[update] analogue transmissions are still found worldwide (though the United States is currently scheduled to require broadcasters to switch off the NTSC service in 2009TSC may still be a viable transmission means for cable television for several more years). Many artistic settings are still made by using test cards or test patterns in conjunction with devices like waveform monitors and vectorscopes (most modern waveform monitors include vectorscope capability), and while digital transmission eliminates many of the “analogue” effects associated with analogue television, digital broadcasting has its own set of issues.
Gallery
WHO-TV test pattern
Indian Head test card
SMPTE color bars
Philips PM5544
Philips PM5644
EBU test card
Multiburst test card
FCC Composite test card
T-Pulse test card
Telefunken FuBK test card
KS2XBS “Phonevision” test pattern
Testcard from the Netherlands Public Broadcasting, used from 1978 till 1988
Testcard from the Romanian Television, used from the mid 60s till 1983. This was the second testcard used, after the Soviet inspired -0249 (1956 – mid 60s)
Ex-USSR television test card (Ueit, ).
Early soviet test card (TIT-0249BIS, -0249).
UK Test Card timeline
Year
Notes
Image
1934
The first testcard “Tuning Signals” was broadcast by BBC 1, the earliest being a simple line and circle broadcast using Baird’s 30 line system, and used to synchronise the mechanical scanning system
1947
The first testcard, Testcard A is broadcast on the BBC network
1948
Testcard B. Used behind the scenes, but not broadcast
1948
Testcard C, the far superior of this and the previous, is released. Lack of specification means that there were many variants released with subtle differences
1955
The ITA Broadcasts an unlabelled testcard for the upcoming ITV service
1955
A further ITA testcard featuring a greatly simplified testcard C is broadcast
1960s
The ITA “Picasso” Testcard is released
1964
Testcard D is released in 405 line format. Music as well as test tones were regularly used to accompany this image on BBC1 and ITV
1964
Testcard E is released to comply with the BBC’s new 625 line standard. Numerous television vendors complained that the image made on screen was unattractive – its sinusoidal frequency gratings looked soft – and TCE was withdrawn after only five days of service
1964
Once testcard E was withdrawn, the BBC released a modified version of TCC with more specific details on the inside circle.
Main article: Test Card F
1967
Testcard F, the most famous and used testcard, is released by the BBC to coincide with colour transmissions that started that year on 1 July on BBC2. Only limited programmes were available in colour from the start. The full output became colour on BBC2 on 2 December the same year. It features a picture of Carole Hersee playing noughts and crosses
1969
BBC1 & ITV begin colour transmissions and usage of testcard F. The BBC1 version was simply the BBC2 version of the 35mm transparency with the letters “BBC1” electronically keyed over the top of “BBC2 COLOUR”. The ITV version had the name of the station operating in that particular area, except London, which read “Thames Television/London Weekend Television”. TCF was broadcast simultaneously on both VHF-405 lines and UHF-625 lines (the system it was designed for in the first place)
1970s
Testcard G – a variant of the Philips PM5544 test pattern, is created but only broadcast occasionally on BBC1 as well as on BBC2.
1979
The Independent Broadcasting Authority (IBA) – Independent Television Authority (ITA) prior to 1972, introduce ETP-1/Electronic Test Pattern One to replace Testcard F within the ITV regions. ETP-1 was also extensively used by Channel 4 and S4C in the run up to the launch of these channel’s in November 1982 – using ‘IBA:CH4’/’IBA:S4C’ captioning instead of the ‘IBA’ captioning used by ITV. ETP-1 became a common sight on British television in the 1980s up until ITV started broadcasting 24 hours a day in 1988. Channel 4/S4C continued to use ETP-1 – using ‘NTL:CH4’/’NTL:S4C’ captioning from 1990 after the Broadcasting Act 1990 saw the privatisation of the IBA’s transmitter network and sale to National Transcommunications Limited/NTL. However ETP-1 disappeared in1992 when Channel 4 simply broadcast its teletext service 4-Tel on View whilst off air – it later began 24 hour broadcasting in 1997, with S4C simply broadcasting black screen and tone whilst off-air.
1984
Testcard F is converted to an electronic format
1999
Testcards J and W are released, replacing F. Testcard J is a modified version of F, with improvements including an improved centre picture and a dot in the white area at the top. W is similar but designed in 16:9 widescreen.
2007
British Sky Broadcasting create a 1080 line high definition test card for their recently launched HD service. The style is similar to Testcard F with the girl being replaced by Myleene Klass
Test patterns for photocopiers
A lesser-known kind of test pattern is used for the calibration of photocopiers. Photocopier test patterns are physical sheets that are photocopied, with the difference in the resulting photocopy revealing any telltale deviations or defects in the machine’s ability to copy.
In numismatics
Television has had such an impact in today’s life, that it has been the main motif for numerous collectors’ coins and medals. One of the most recent ones is The 50 Years of Television commemorative coin minted in March 9, 2005 in Austria. The obverse of the coin shows a “test pattern”, while the reverse shows several milestones in the history of television.
Monoscope
Main article: Monoscope
A monoscope.
Close-up, showing test card target.
Rather than physical test cards, which had to be filmed, an alternative was to use a cathode ray tube, driven backwards from a television tube, so that it generates an image rather than displaying an image. These were fragile, but had advantages over test cards, always being properly framed and in focus. They fell out of use in the 1960s, as they were not able to produce color images.
References
^ Test card special, by Ryan Dilley, BBC News, 19 April, 2001
^ “Samsung SF531P PCSTATS Review – Printer Test Patterns”. Pcstats.com. 2007-10-15. http://www.pcstats.com/articleview.cfm?articleid=1339&page=4. Retrieved 2010-01-01.
^ “Projection: Room A / Room B”. Thing.net. http://www.thing.net/~grist/cyano/jangva/roomecho.htm. Retrieved 2010-01-01.
External links
Wikimedia Commons has media related to: Test patterns
mire.project – Street art work about television test patterns
TV Testbild – very informative, but in German language only
Burosch AudioVideo-Technology – advanced HDTV test patterns
The Test Card Gallery
Television Test Cards, Tuning Signals, Idents and Clocks
Barney Wol’s website has details of the development of UK testcards F, J and W
Test Card Circle Details of Test Cards and music.
625.uk.com Flash Files – high quality Adobe Flash examples of almost all British test cards and station idents (the test cards are at the bottom of the page and include C, D, F, J, W and ETP-1)
Irish TV Testcards – Pictures of Test Cards used by the Irish TV broadcasters RT, TV3 and UTV.
SMPTE Bars in CSS and XHTML
SVT test cards – Picture gallery of test cards from Swedish Television (SVT), in Swedish
Russian Test Cards
Maximum Testcardosity test cards’ resources, history and galleries
equasys Video Test Collection – MPEG-2, H.264, WMV and Flash video test sequences for PAL, NTSC and HDTV video formats.
Categories: Test cards | Broadcast engineering | PatternsHidden categories: Articles containing Russian language text | Articles needing additional references from August 2006 | All articles needing additional references | Articles containing potentially dated statements from 2006 | All articles containing potentially dated statements
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