Calibration establishes hue and intensity for RGB primary color components which, in turn, affects all other colors. Once a month the HP Advanced Profiling Solution (APS) displays a reminder to validate the display profile. Actually the reminder can be set from 1 to 4 weeks or indefinitely. This only occurs during system restarts. For displays left on continuously, an iCal reminder can be helpful. Today an alert went off so let me walk you through the calibration process.
Glossy LCD screen Apple iMac displays are very bright. With brightness turned to the minimum, the one calibrated today with 1.8 gamma has a luminance of 160 -- far exceeding the typical target of 120. Though this means it may be not easy to simulate paper brightness, good color balance (representation of hues) is possible. Setting gamma to 2.2 brings luminance closer to target at 140. Display brightness dims after a couple of years allowing the reference 120 to be reached with 2.2 gamma.
Target calibration values are selected. The 6500K white point and 1.8 gamma are native settings. (2.2 gamma is preferred.) The 160 luminance is set higher than normal so profile summary will not indicate it is out of spec.
The eye-one calibration device is placed on the display. Moments later luminance is verified before various shades of grey and colors are measured as they flash on the screen. The profiling summary grades the quality of the profile relative to established targets. Afterwards the ICC profile is saved and a reminder set to validate in the future.
An optional step to validate the created profile is advised. This is because the profile just created used whatever prior profile was selected during its measurements. Validation uses the new profile when measuring color patches.
