Calibrating Your Monitor - Adobe PHOTOSHOP 5.0 User Manual

82 CHAPTER 5
Reproducing Color Accurately
When opening an RGB, Grayscale, or CMYK
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file, to compare the file's color space to the color
space defined in the appropriate Setup dialog box.
If the two color spaces are not the same, you can
convert the file. (See "Managing ICC profiles in
files" on page 99.)
When viewing a file on-screen, to convert the file
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to the monitor's color space. This only affects the
display, not the file—Photoshop assumes that the
file's true color space is the one defined in the
appropriate Setup dialog box.
Note: If you have disabled the Display Using
Monitor Compensation option in the RGB Setup
dialog box, files may not be displayed accurately in
the monitor's color space. (See "Entering RGB setup
information" on page 84.)
Changes to the Setup dialog boxes do not affect the
pixel values of open images. However, the on-
screen appearance may change, because
Photoshop then displays the image assuming a
different native color space.
For example, suppose your file was created in the
sRGB color space and you use the RGB Setup
dialog box to change the color space to Color-
Match RGB. Photoshop will treat your file as a
ColorMatch RGB file when it displays it online,
even though it is not changing the actual pixel
values in the file.

Calibrating your monitor

The Adobe Gamma utility lets you calibrate the
contrast and brightness, gamma (midtones), color
balance, and white point of monitors. This helps
you eliminate any color cast in your monitor
display, make your monitor grays as neutral as
possible, and standardize your display of images
on different monitors (whatever the combinations
of monitor and video card). The utility then saves
these settings as an ICC profile for your monitor.
The following guidelines can help you in
calibrating your monitor:
You can use a third-party calibration utility and
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an ICM 2.0- or ColorSync-compatible ICC profile
generator instead of the Adobe Gamma utility. See
the utility's documentation for details.
You don't need to recalibrate your monitor if you
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have already done so with an ICC-aware
calibration tool and you have not changed your
monitor settings.
Gamma settings saved by the Monitor Setup
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Utility (Windows) or the Gamma control panel
(Mac OS) in Photoshop 4.0 and earlier are not
supported.
You only need to set calibration and save it as an
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ICC profile once on your system, for all applica-
tions, unless you change any of the factors
affecting calibration. For example, if you change
the room lighting or readjust the monitor