Test Card W
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Test Card W is a test card, an image used to determine the quality of a broadcast television picture. It is an updated 16:9 (1.78:1) widescreen version of Test Card F, which was created by BBC engineer George Hersee. Test Card W is similar to Test Card J, the latter being a 4:3 version. Both appeared for the first time in November 1999.
The colour-bars on the top and right of the image are the full 100 percent saturation version, unlike Test Cards F and J which use the 95 percent type. Extra mirrored arrow-heads on the central axis at the sides mark the positions of the middle 4:3 and 14:9 sections of the image.
As television is usually broadcast 24 hours a day, the test card is now rarely used. The last known occasion that this card was broadcast on British screens was Friday 9 January 2004, when early morning tests were carried out on BBC One and BBC Two. BBC Two still closes every weekday morning between 4.00 and 6.00 and during Educational Holidays, but pages from Ceefax rather than test cards are broadcast on these occasions.
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[edit] Sightings
The last occasion that Test Card W was broadcast on BBC One and BBC Two was Friday 9 January 2004. The times before that were for a few minutes on 3 December 2003 on BBC Two during the 2003 tests; seen for around 20 minutes during Pages from Ceefax time from about 02.20 on 22 June 2003; a brief appearance in the early in the morning of 14 August 2001 in a programme gap; on BBC One between 03.00 and 04.00 on 27 July 2001 (while BBC Two was on reduced power); and during the August 2000 BBC rebroadcast test.
On Freeview, however, Test Card W can be called up at any time using this procedure:
- Tuning to the BBCi channel (105)
- Pressing "yellow" within 30 seconds of the BBCi background appearing
- Tuning to another channel
- Tuning back to BBCi (105)
- Pressing "green" within 30 seconds of the BBCi background appearing
- Waiting for the word "secret" to appear at the top right corner of the screen and a status page appearing
- Pressing "green" again.
Test Card W should appear within 30 seconds.[1]
[edit] Instructions
PRELIMINARY NOTES
1. Make sure you have the user manual and know where the controls are.
2. Do not do this if you are unsure of any of the controls or their effect on your television picture.
3. It is best to do this in a darkened room, it doesn't need to be completely dark but if it's too bright or there is a lot of light falling on the screen the results will not be good.
4. Many modern flat screen televisions have presets for sound and picture. Write down which one you use so if you get lost you can always go back and start again.
5. If you have a PVR it would be a good idea to record the test card section of the promo. Most of the line up can be carried out on a freeze frame of the test card. If you do this please be mindful of the warning above about screen burn.
6. If your TV has it, change the picture settings mode to "manual" or the equivalent, so any inactive controls become active allowing you to change the settings on the TV.
7. Turn the sharpness setting to off or zero. If there are any picture enhancing options, make sure they are turned off or to zero (if you can). Remember, on some TVs the sharpness control has a centre zero allowing you to soften pictures - please don't do that!
So to start:
BRIGHTNESS AND CONTRAST
There is a GREY SCALE to the left of the picture on the test card. It's there to show the correct black and white levels of the picture. Broadcast displays have the ability to adjust the grey level independently so there is a linear grey scale between the black and white blocks. (...)
The top white block has two spots. As I said earlier, usually the white block is peak white with the right spot higher (super white) and the left spot slightly lower. On our test card, the levels are slightly reduced.
The bottom black bock has two spots, the right hand one is below black level (sub black) and the left is slightly above black. The modifications to the test card have not change these levels.
BRIGHTNESS
To set the brightness:
1. Turn your brightness control up until you can see both (black) spots.
2. Turn the brightness down until the sub-black spot disappears but make sure you can still see the left slightly brighter spot.
CONTRAST
When a broadcast monitor is lined-up properly, we use a meter to check the white level however on a domestic television contrast is more a matter of personal choice and will be different on different types of display (LCD, Plasma, Projector etc.)
Adjust the contrast until you like the overall look of the test card while you are doing this, keep an eye on the spots in the top white block to make sure you can still see the left hand one. It doesn't matter if you cannot see the super white spot so don't worry if it's not there.
COLOUR
Again colour level is very much down to personal taste but most TVs have too much of it! Too much colour makes pictures look very odd. It will also make some colours bleed into each other or appear to move so the colour smears over the edge of the object - in other words someone wearing bright colours clothes may have the colour slightly off to one side! The best bit of the test card to use to set colour is the picture of Carole.
The centre of the test card has all you need to get the colour right. Carole's face should look natural and the primary colours in the picture (red dress and green and blue of the clown) should not be very bright. Colour is a subjective setting so just make sure you like it. Remember, if your colour setting was previously set very high you may not like the correct level until you get used to it!
One of the experts at BBC Research suggested another way to adjust colour level.
Get some Lee Lighting Filters No.181 Congo Blue and place it over the screen. This has the same effect as turning off the Green and Red leaving the Blue component of the picture. Looking at the colour bars around the edge to the test card, adjust the colour control until they all look the same brightness. There are some commercially available line up DVDs that use this method.
When you have adjusted the BRIGHTNESS, CONTRAST and COLOUR have a look at the promo again to see what you think. Watch it for some time so you get used to the new settings and see several different type of programme.
SHARPNESS
I have the sharpness control on my TV set to zero but some of you may want to add a little bit if the picture looks very soft.
To the right of the picture of Carole is a set of "frequency gratings" The frequencies are:
1. 5MHz
2. 10MHz
3. 15MHz
4. 20MHz
5. 25MHz
6. 30MHz
The BBC HD transmission system will pass frequencies 1 - 4. Most domestic displays will show 1-3 correctly but the 4th might not look quite right. A 50' 1080p display should be able to resolve the 4th grating satisfactorily.
PICTURE SIZE AND POSITION
Not all TVs offer menu setting that allow you to change picture size and position. Even if your TV does allow you to adjust size and position, it's not a good idea not to make anything but small changes unless you know what you are doing. Make a note of the current setting BEFORE you change anything!
Most displays lose a small amount of picture all round. This is called "overscan", it is perfectly normal and programmes have always been made taking this into account.
Some flat screens do have the option to either turn overscan off or reduce the picture size.
It is perfectly safe to use the "overscan off" option on you TV but you should not use the picture size controls for anything more than small changes.
The full test card should look like this, with the diamond points just touching the edge of the screen all the way round. As a mater of interest, the cross on the Noughts and Crosses game is the centre of the picture!
You should now have a picture that looks fairly close to the one we see before transmission. Again watch some of the promo to get used to the new settings. Also if you have turned overscan off, you might want to look at some SD channels to make sure you don't see extra bit of the picture you don't like. You may see some white lines at the top of the screen on some News programmes for example. This happens when signals are brought back that don't fully meet the broadcast standards, but have to go to air too quickly (if not live) so it isn't possible to correct them.
(provided by Andy Quested)
