Graphics Programs Reference
In-Depth Information
and enjoy your calibrated view of the digital world. After calibration,
don't be alarmed if you see what I like to call “puck grease” from the
rubber of the instrument on the display. A wonderful product to remove
this is the Micro-fiber cloths from http://www.klearscreen.com/
products.html.
Other Areas to Watch For
Once the display is calibrated and profiled, don't alter the display in any
way! This would include changing the resolution and even the bit depth.
Each display resolution will need its own calibration and profile. For this
reason, you'll likely want to work with one display resolution and bit
depth. Note that the Sony Artisan allows a user to calibrate multiple
display resolutions and saves the calibration data for each. The user can
move from resolution to resolution and the color calibration and profile
are updated with a single click. Photographers ask me all the time if it's
possible to calibrate a display and then move that calibrated display to a
different computer. The answer is no. The calibration and profiling is
based upon the unique video signal of each computer.
It's a very good idea to set the desktop pattern to neutral gray. A col-
orful desktop pattern might be visible behind images and can affect your
ability to judge color. Do not allow the operating system to put a display
in sleep mode or you will need to wait for the unit to warm up once
again. A screen saver should be fine since current is still running through
the display. The ambient light in a room where the display is calibrated
should remain constant. Remember when you turn on your display, you
are viewing the darkest possible black that display can produce. An
increase in ambient light will increase the luminance of black. If you are
aiming for a high contrast ratio, doing so in a light room is not possible.
With an LCD you can get away with a slightly higher ambient due to the
greater luminance of white. With white at 90 cd/m
2
, an ambient of < 16
LUX
is recommend. At 140 cd/m
2
use an ambient of < 32 LUX. A few
software products actually will let you measure the ambient light with
the instrument. This has no effect on the calibration. Some products warn
the user if the ambient light is too bright for optimal results.
These recommendations are based on an ISO specification designed
for office environments, not color critical viewing. Use the targets rec-
ommended earlier instead. Obviously, this isn't always possible but try to
work in as dim an environment as possible and more importantly, an
environment that is consistent. If you have windows shining various
intensities and color of daylight into your environment, it's going to be
difficult to judge color. Thankfully, there's a relatively new invention
called curtains! Be sure that any light in the environment does not
directly strike the display. This is where a good monitor hood can help a
great deal. If your display didn't ship with one, make a hood even for
those LCD units. They don't look sexy but keeping stray light for
Definition
LUX:
Lumens per square
meter; a unit of
illumination. To provide an
idea of the values
discussed, full daylight
ranges approximately from
3200 to 10,000 LUX; a
typical office is
approximately 200 to 400
LUX; and twilight is
approximately 10 LUX. See
http://www.intl-light.com/
handbook/irrad.html.
