Your monitor’s gamma tells you its pixels’ luminance at every brightness level, from 0 to 100 percent. Lower gamma makes it hard to see brighter highlights. Higher gamma makes it harder to see darker shadows. For example, Samsung monitors have three different gamma modes available: 2.0, 2.2 and 2.4.
Gamma is important because monitors with poor gamma can either crush detail at various points or wash it out, making the entire picture appear flat and dull. Proper gamma leads to more depth and realism and a more three-dimensional image.
Typically, if you are running on the Windows operating system, the most accurate color is achieved with a gamma value of 2.2 (for Mac OS, the ideal gamma value is 1.8). So when testing monitors, we strive for a gamma value of 2.2. A monitor’s range of gamma values indicates how far the lowest and highest values differ from the 2.2 standard, (the smaller the difference, the better).
In our monitor reviews, we’ll show you gamma charts like the one above, with the x axis representing different brightness levels. The yellow line represents 2.2 gamma value. The closer the gray line conforms to the yellow line, the better.
This article is part of the Tom's Hardware Glossary.