VP400 Series Video Pro Form7343A Operation Manual
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When the Pluge pattern is selected with the NTSC format, the VideoPro automatically displays
an NTSC pluge pattern with a 7.5 IRE black setup level. When an HDTV format is selected, the
VideoPro displays an HDTV pluge pattern, without black setup.
To adjust the brightness control on an NTSC or HDTV display device with the Pluge pattern,
watch the second box from the inside, which is alternating between black and blacker-than-black
(7.5 IRE and 3.5 IRE in NTSC, 0 IRE and –4 IRE in non-NTSC formats). Adjust the brightness
control until the black and blacker-than-black levels appear the same and no flashing can be
seen. The outer 10 IRE box should still be slightly visible. The same method is used for HDTV,
although the pattern IRE levels are different.
If the brightness level of the outer two rectangular zones does not remain constant as the second
zone from the center alternates between black and blacker than black, the display has less than
perfect DC restoration. This can be seen especially well with the brightness (black level) control
adjusted to a slightly higher than normal setting. In this case, you will need to decide, based on
the primary use of the display, whether the black level should be adjusted on a pattern with low
APL or high APL. If the display will usually be viewed in a darkened room, adjust the brightness
control with a low APL pattern, such as the Pluge pattern. If the display will usually be viewed in
a bright room, adjust the brightness control with the pluge levels in a medium or high APL
pattern, such as the SMPTE Bar pattern or one of the Window patterns set to a high IRE level.
Sharpness Control
The sharpness control is designed to enhance the fine detail in a picture, independent of picture
content. It was originally introduced in color TVs with notch filter luma/chroma separation that
removed high frequency detail in the black and white portion of the picture. The sharpness
control was designed to put some of that detail back into the picture. Most modern TVs now use
a comb filter, which doesn’t lose the high frequency luminance detail. If a comb filter is used,
there is no longer a real need for the sharpness control. If the sharpness control is improperly
adjusted, it will either add picture distortion or reduce picture resolution.
The VideoPro Sharpness pattern is designed for
adjusting the sharpness control. To calibrate the
sharpness control, watch the left and right edges of
the needle pulse lines. If the sharpness is set too
high, a faint duplicate line will be seen beside the
original line. This ghosting affect is unwanted
picture distortion.
Do not adjust the sharpness control low enough to
lose resolution or brightness in the multiburst bars.
Adjust the sharpness control to achieve the best
balance between ghosting and poor resolution.
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