References and Further info
How to Use Test Card F – Russ J Graham (Transdiffusion, 2014)
BBC Test Cards - The Test Card Gallery – MHP from Transdiffusion
https://www.radios-tv.co.uk/test-card-f/
Television Test Cards, Tuning Signals, Idents and Clocks
Widescreen Test Card Development
In 2007 Liz Hoggard interviewed Carole Hersee for The Independent
The Story of Carole Hersee - The BBC Test Card Girl - Prentis Hancock (2020)
The Test Card Girl: The Lasting Legacy of Test Card F - Adam Martyn (2022)
Test Card F – An Unintended TV
Icon
A testcard is a graphic designed
to help aid the calibration of television cameras and screens. This graphic
comes in several forms – an electronically-generated pattern, a transparent
slide or an actual card placed in front of a camera. Test cards had been in use
since television began in the 1930s, and some designs have become icons, due to
their use during non-programmed hours on TV, which were a lot before the 1990s.
The BBC have used testcards on television since 1934 (on John Logie Baird’s
30-line mechanical system). But the introduction of colour TV created the need
for a uniquely new test card. BBC Engineer George Hersee (with help of his
daughter Carole) created what became a TV icon. First appearing on BBC 2 on 2nd
July 1967, Test Card F (in some form) has been used in about 30 countries
outside the UK, which has resulting in George’s daughter becoming the most
screen-burned human face in the history of television.
“a joint committee representing the BBC, the ITA [Independent Television Authority], the EEA [Electronic Engineering Association], and BREMA [British Radio and Electronic Equipment Manufacturers' Association] set to work to design a suitable card for transmission when a [colour] service started.” – George Hersee, A Survey of the Development of Television Test cards used in the BBC (BBC Monograph no 69, 1967)
On top of the card is row of colour bars, which can be used to check the accuracy of the colours on screen. The colours are in order of luminance, with the brightness on the left and darkest on the right.
The white grid lines are used to check how straight the picture is on screen
These black lines are to check if the three electron beams in a colour TV are in perfect alinement
These “Border Arrows” are used to check the width, height, and centring of the picture on screen
This grey scale is to check a TV’s ability to display such tones distinctively. Ideally, you should be able to see the circles in the top and bottom rectangles.
These “Frequency gratings” generate the equivalent of a square wave signal in the video signal. The numbers (later removed) note their frequency in megahertz. On monochrome TVs, all these gratings should be clearly seen, but it is normal for the bottom two to look weaker than the top four. On colour TVs the bottom two appear more weaker, even becoming invisible. That is normal.
This “Letter Box Pattern” is used to show if a TV has a poor low-frequency response, which causes streaking to the right at the right-hand edges of these black and white rectangles.
These “Diagonal Corner Stripes” are used to check how uniform the picture’s focus is.
The tic-tac-toe game on the blackboard provides a high contrast image that can be used to calibrate the alinement of the three electron guns in a colour TV. The “X” marks the exact middle of the card … in later versions. In the original version, the picture was not centred, indicating that that the “X” may have been just decoration, initially.
The coloured squares on the
black frame (which is usually not seen on normal TV viewing) are there to
detect issues with a colour TV’s reference oscillator and colour processing
circuitry. Issues that are usually only fixable with more than just a
screwdriver.
The Picture
The idea of using an image on a test card was not new to Test Card F. France’s channel RTF1 had used a test card, featuring the Marly Horses sculpture, from 1953 to 1983.
“The picture requirements were
quite exacting:
(a) To have a reasonable area of
flesh tones.
(b) To include areas of bright
colours to counteract the large black/white areas of the rest of the card.
(c) To have a white-on-black
contrast near the centre of the circle. This is necessary in order to apply the
convergence check.
(d) To be a pleasing picture as it is probably going to be seen on receivers in dealers’ windows for several hours per day.
… the first problem was to select a model. The contrast range of the brightness had to be restricted so that dark hair was unacceptable. After many tests a child’s face was eventually chosen, not only because of the appeal of such a face but also because an older face would involve make-up, and fashions in this change yearly. This could lead to having to remake the picture each time the fashion changed, or else be accused for been out of date. Furthermore, an older model would have involved considerably more difficulties over modelling and reproduction fees – designing the card was trouble enough. Having once had the happy idea of getting the highlight by means of chalk on a blackboard, the rest of the composition soon fell into line.” – George Hersee, A Survey of the Development of Television Test cards used in the BBC (BBC Monograph no 69, 1967)
“They didn't want to use an adult because women's fashions and hairstyles change constantly. So that's why he [George] thought of us children.” – Carole Hersee
The “chalk” is painted on, to make it more visible
Carole was left-handed, and the committee thought this would make a “bad image,” so the final photo was mirrored to her look right-handed
Carole Hersee
“It was 1967 and I was eight. It
was a sunny day and my father, who was an engineer at the BBC, told my little
sister Gillian and me that he wanted to take some photographs of us in the
garden. He brought along a hat, flowers and a wheelbarrow. ….
My father chose me because Gillian had two front teeth missing. The next thing I remember is going into a studio to do the pictures professionally. This time the set included a clown and a blackboard, and I remember eating lots of biscuits while they played around for ages with the game of noughts and crosses …” – Carole Hersee
Carole was paid £100 for the gig. After
becoming an unintended TV star Carole was often teased about it at school and
often had to try to prove she was the girl on the TV, bringing Bubbles with her
occasionally as proof. Her non-believing school headmaster even once disciplined
her over this. She got a lot of fan mail, which was screened by the BBC. One of
the few the BBC allowed through to her invited her to open a dog show, which
she did. In 1971 Pye Television gave her a special award for 'The Most Seen
Girl on TV.'
This early experience with fame made her hate the limelight. As she got older, she cut her hair short and avoided press interviews. With her parents been BBC employees she got to visit Broadcasting House many times, with particular interest in their wardrobe department. The staff there recommended her to get a placement at costumers Bermans & Nathans. She spent three weeks there and never went back to school. She became a seamstress for them and, from 1979, worked in the wardrobe department at Shepperton Studios. She designed the costumes for several West End productions and movies, including Flash Gordon, The Last Emperor, Dangerous Liaisons and The Sheltering Sky.
“The colours were very carefully chosen for technical reasons - a red T-shirt and hairband for me, a green outfit for the clown, plus yellow and blue - but it completely passed me by. I was terribly hot and all I wanted to do was to go outside and play.” – Carole Hersee
Bubbles the Clown
The clown doll was made from a kit by Carole. Bubbles was originally blue and white striped. To add green to the scene, Bubbles had a green wrap sewn on him.
In the original Test Card, the lab tinkered with the green of Bubbles’ dress, making it more “fluorescent.”
Later Versions
Test Card F was originally a photographic
slide, containing two transparencies – one of the monochrome background the
other contained the colour information. In 1984 it was turned into an electronic
file. In 1998 Richard Russell redesigned the card for digital television,
creating Test Card J (for 4:3 screens) and Test Card W (for widescreen TVs).
Part of the process included a high-res (5,000 x 5,000 pixel 48-bit colour depth)
digital scan of the original transparency of Carole, borrowed from George. The
resulting cards cropped less than the original card, showing more detail,
including Bubbles’ left hand. These cards first appeared on TV in November
1999. In 2006 an HD version of Test Card W (unofficially called Test Card X)
was created for the BBC HD channel.
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