This method gives
the most accurate Brightness and Contrast setting for CRT monitors.
It results the same accurate black-point no matter if a system level
gamma calibration is active or not since only the R,G,B=0,0,0 level
(pure black) is used and the pure black is not affected by any CRT gamma
correction. This method is also platform independent.
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1.
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Set
the room lighting to normal image editing condition. This is dim or
moderate, not light. Minimize possible glare (so that the CRT screen
is not directly exposed to light sources). |
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2.
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Let
the monitor to warm up for 1 hour in order to allow it stabilize. |
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3.
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This method
needs a level 0 background on the desktop. Go to the Display
Properties, select Appearance-tab, then choose Item=Desktop
and change it's color to Black, verify that it is R,G,B=0,0,0.
In case you
have plenty of icons on the desktop drag them to the bottom of the
screen so that their luminance affects as little as possible to
your vision.
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4.
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Locate the
the Contrast control of your monitor. This control
adjusts the maximum displayed luminance, so it is range control.
It is best to keep it always at maximum, only if the highlights
are too light for your vision bring it down to a suitable level.
Set the Contrast
control of the monitor now to the maximum.
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This is often called as the Contrast. Actually it adjusts the
maximum luminance level of the monitor.
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5.
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Locate the
Brightness control of your monitor. Despite of it's
name this control affects to the black-point of your system. If
the it is at a too low setting then the monitor does not show dark
shades of the images properly they are cut off to pure black. If
it is at a too high setting then very important part of the available
contrast range is not used, there is no good black anywhere on the
screen and all the images appear flat and foggy.
Set the Brightness
control of the monitor now to maximum as the starting point of
the black-point calibration.
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This is often called as the Brightness. Actually it adjusts the
the black-point of the monitor.
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6.
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Locate the
Vertical Height control of your monitor to make the
active scanned display area vertically smaller, so that a black
border will appear on top and at the bottom of the screen. This
black area is now not scanned by the electron beam at all so it
gives a perfect black reference point, as good black that there
can be on the CRT.
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Vertical Height or
Vertical Size
control
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7.
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You should
now have a situation like this on your desktop. If
it is so then jump to step 8.
else continue
with step 7a.
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7a.
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In case it
is not possible to adjust the CRT so that the non-scanned area is
visible in step 7 then undo step 6 and locate the Vertical Centering
control of your monitor,
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Vertical Centering or
Vertical Position
control.
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7b.
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and use the
Vertical Centering control to move the active scanned display area
downwards until you can see the non-scanned area at the top of the
monitor screen. If
it is so then jump to step 8.
else continue
with step 7c.
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7c.
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Some monitors
do not show the non-scanner area at all. With such monitors show
full screen black with absolutely nothing else shown but the R,G,B
level 0,0,0 all over the screen. Do not use the DOS-prompt to show
a black screen since the DOS prompt often switches to a different
refresh mode. Now make the room completely black, with no light
at all. Set the brightness to minimum and slowly increase
it until the screen starts to emit light. Now adjust slowly and
carefully back and forth around this point until you find the exact
location that is just below the point where the screen emits light.
Jump to step
9.
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8.
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Now use the
Brightness control to adjust the active area so that
it just merges with the black of the non-scanned area.
The Brightness
setting has to be on the verge so that the smallest increase
to it would make the active scanned area discernible.
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9.
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Blackpoint
calibration is now complete. Please adjust the scanned area back
to how it was.
Remember to
keep the the ambient lighting level low or moderate and especially
constant and do remember to calibrate the blackpoint periodically,
but only after the monitor has been stabilized.
If you have
system (gamma) calibration such as AdobeGamma active you will need
to re-check it now but do not adjust the black-point there, it is
now very accurately set.
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Where
to go
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Gamma-space
evaluation is here
Photoshop
calibration page is here
An
easy but very accurate method to calibrate the color-temperature
of the monitor to daylight (D6500) is explained on the Photoshop
calibration page but is not Photoshop spesific.
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