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test patterns
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test patterns
test patterns
The DVD32FLR has a in-built test pattern generator to assist you in adjusting your picture, PAL
or NTSC, for best performance.
Many display devices are wrongly adjusted when leaving the factory because they need to
overcome the bright lighting in the show rooms from which they are usually selected.
However, once installed at home, the viewing conditions vary considerably from those in the
show rooms, hence display devices need re-calibrating.
Most important for a perfect picture is the absence of surrounding light in the room,
particularly light which can hit the screen. An often suggested low brightness light, placed
behind the screen (hence preventing it from reflecting in the screen) should only be used if
you want to watch tv leisurely for a long period of time. For best movie presentation, keep
the surrounding light intensity as low as possible.
It is not just the absence of surrounding light which can improve the performance of your
display device, it is also the colour of the walls, as these will also reflect light, emitted (or
reflected, when using a front projector) from your screen, ‘bouncing’ it back on to the screen
to ‘wash-out’ the picture. The perfect home cinema would be pitch black with no added light
in the room! Not the most pleasant of rooms, but highly effective. The result would be great
picture quality, assuming the display device is up to the task and adjusted properly. A more
practical solution is walls painted in darker colours without a reflective surface.
Black is the absence of light, and this is the first parameter you should adjust. Use the display
device’s black level control which some manufacturers call, quite inappropriately, brightness.
The DVD32FLR includes two test patterns, PLUGE 1 and PLUGE 2, which will allow you to
adjust the black level until black becomes ‘really’ black (and not just a dark grey). If you set
the black level too high then a scene filmed at night looks like a scene filmed in the afternoon
(as black will be replaced by dark grey). However, if the black level is set too low then the
picture will lose detail in dark scenes.
Both test-patterns include a signal, created by hardware circuitry inside your DVD32FLR
(1)
,
which produces a level which is electrically below black, i.e. invisible if the black level of the
display device is correctly adjusted. This signal is called PLUGE (Picture Line Up Generating
Equipment). Both test patterns also include, to the right of PLUGE, separated by a black
zone, a dark grey bar (electrically above black, by exactly the same amount as PLUGE is
below).
If the black level is correctly adjusted then PLUGE is no longer visible but the dark grey bar
still (just) is.
PLUGE 2 contains, in addition to PLUGE 1, a brilliant white field to check if the black level is
affected by high picture contrast.
brightness (black level)
1. The DVD32FLR will not display the blacker than black test signals recorded on some test discs as it will remove those ‘out of spec’ signal
levels. Some video processors will not display PLUGE at all
GRR00868.01-DVD32RFLR UM 5/30/02 12:25 PM Page 30