Monitor Gamma Evaluation

This exercise will accurately evaluate the gamma of a monitor. You can also use one of these charts as the backgound image or wallpaper of your desktop, this will greatly help monitor calibration with AdobeGamma or a similar calibration&profiling utility. In Windows system simply right-click the desired gamma chart and depending on your Web browser select "Set as Wallpaper" or "Set as Backgound".

The chart has the following sections:

• On the far left: Gray gamma comparison swatch. With a perfect gamma match the left and right portions of the swatch have the same luminance.
• In the center: R, G and B gamma comparison swatches side by side. With a perfect gamma match the R, G and B swatches all appear as gray with the same luminance.
• Top right: High level blackpoint evaluation, the pattern must be (barely) visible.
• Bottom right: Low level blackpoint evaluation, the pattern must not be visible.

Preparation for the evaluation:

First: adjust the Brightness and Contrast controls of your monitor accurately. This really must be done, the two blackpoint evaluation sections in the gamma calibration targets will give rather accurate blackpoint setting but they should be considered as evaluation only. When done make a small mark to the Brightness control this setting should not be changed, it is accurately set now. It needs to be periodically calibrated but not changed on the fly.

Second: open an gamma image by clicking a link on the left frame, evaluate the gamma match. Choose an another chart until you see a good gamma match all over the two gamma swatches.

Please note that the Monitor Calibration Targets must be viewed at such distance that the dithering is fully averaged by the eye. This is about 1.5 to 3 meters, depending on the resolution that the monitor is set to.

Notes:

The display driver in Mac systems apply partial monitor correction at 1/1.45. Since CRT monitors natively have gamma 2.50 the gamma of an uncalibrated Mac is accurately 2.5/1.45=1.72, not the 1.8 that is usually mentioned. PC/Windows systems do not adjust the display path so the gamma-space of uncalibrated PC system is 2.50.