The relationship between the input signal and the luminance of a monitor is not linear but exponential with gamma being the exponent. Monitor gamma values usually range between 1.4 and 3.2. Because only a gamma value of 1 resembles a linear relationship, a gamma correction is necessary to achieve maximum reproduction quality. A monitor gamma value of 2.2 has become the de facto standard for Windows, the Internet and the digital photography. Under Windows a gamma correction is already automatically applied. This yields a linear luminance distribution for monitors with a real gamma of 2.2. Because most computer monitors do not have a real gamma of 2.2 an additional correction is required. With QuickGamma you can calibrate your monitor to a gamma value of 2.2 which in conjunction with the automatic gamma correction yields a linear luminance distribution for every monitor. More information and detailed instructions on how to use QuickGamma are available by pushing the Help button in QuickGamma.
Software that can be used as an alternative to QuickGamma: