brightness
(black level)
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 DVD32R 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 DVD32R
(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.
37
test patterns
1. The DVD32R 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 the PLUGE signal at all
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