The chart below enables you to set the black level (brightness) and estimate display gamma over a
range of 1 to 3 with precision better than ±0.1. The gamma pattern is on the left; the black
level pattern is on the right. Before using the chart, the monitor should be turned for on at
least 15 minutes (30 preferred). For flat screen (LCD) monitors, Screen resolution (right-click
on the wallpaper, Properties, Settings) should be set to the monitor's native resolution.


Gamma is estimated by locating the position where the average luminance across the gamma
pattern is constant. You should be far enough from your monitor so the line pattern is not
clearly visible. The example below shows what to look for. The solid areas are calculated from
the equation,


pixel level = 255*luminance(1/gamma) ; luminance = 0.5.


Your monitor's gamma should be 2.2 or 1.8.


2.2 is recommended for Windows, the Internet sRGB color space, and the popular Adobe RGB (1998)
color space. 1.8 is the standard for older Macintosh systems and prepress file interchange. I
aim for gamma = 2.2. Most laptop LCD screens are poorly suited for critical image editing
because gamma is extremely sensitive to viewing angle.


For more information:

http://www.normankoren.com/makingfineprints1A.html#gamad

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