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118
Adobe Photoshop Help
Producing Consistent Color (Photoshop)
Using Help
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118
Calibrating versus characterizing a monitor
You can use profiling software such as Adobe Gamma (Windows) or the Apple calibration
utility (Mac OS) to both characterize and calibrate your monitor. When you
characterize
your monitor, you create a profile that describes how the monitor is currently reproducing
color.
When you
calibrate
your monitor, you bring it into compliance with a predefined
standard, for example, the graphics arts standard white point color temperature of 5000
Kelvin.
Determine in advance the standard to which you are calibrating so that you can enter the
set of values for that standard. Coordinate calibration with your workgroup and prepress
service provider to make sure you’re all calibrating to the same standard. However, if you
have implemented a good color management workflow, you need not calibrate all
monitors to the same standard; you simply need to characterize each monitor to produce
accurate profiles.
About monitor calibration settings
Monitor calibration involves adjusting video settings, which may be unfamiliar to you.
A monitor profile uses these settings to precisely describe how your monitor reproduces
color.
Brightness and contrast
The overall level and range, respectively, of display intensity.
These parameters work just as they do on a television set.
Gamma
The brightness of the midtone values. The values produced by a monitor from
black to white are nonlinear—if you graph the values, they form a curve, not a straight
line. The gamma value defines the slope of that curve halfway between black and white.
Gamma adjustment compensates for the nonlinear tonal reproduction of output devices
such as monitor tubes.
Phosphors
The substance that monitors use to emit light. Different phosphors have
different color characteristics.
White point
The coordinates (measured in the CIE XYZ color space) at which red, green,
and blue phosphors at full intensity create white.
Guidelines for creating an ICC monitor profile
The following guidelines can help you create an accurate monitor profile.
You may find it helpful to have your monitor’s user guide handy while creating an ICC
monitor profile.
•
You don’t need to calibrate your monitor if you’ve already done so using an
ICC-compliant calibration tool and haven’t changed your video card or monitor
settings.
•
Make sure that you are using a standard desktop (CRT) monitor.
•
If you have the Monitor Setup utility (included with PageMaker
®
6.0) for Windows or
the Knoll Gamma control panel (included with Adobe Photoshop 4.0 and earlier) for
Mac OS, remove it; it is obsolete.
•
Make sure your monitor has been turned on for at least a half hour. This gives it suffi-
cient time to warm up for a more accurate color reading.
•
Make sure your monitor is displaying thousands (16 bits) of colors or more.