Datacolor Spyder3 Elite Help Manual page 11

Select Gamma
Help Index
Usual Setting
Gamma 2.2 is the most common choice for tone response because most displays
perform naturally near that value and many of the commonly used color spaces are
defined with that value.
The Purpose of This Step
This screen allows you to specify a gamma or non-gamma curve as the desired tone
response of the display.
The Long Answer
Tone response is a description of how the monitor's output luminance relates to the
input signal. In practical terms, tone response mostly affects the lightness of the
middle and quarter tones of images displayed.
Generally, higher gamma values (e.g. 2.2) cause images to appear with more contrast
and color saturation – usually with a loss of shadow detail. Lower gamma values (e.g.
1.8) cause images to appear with less contrast and saturation but with more detail in
the shadows. But color managed applications adjust for monitor gamma, showing
similar results at a range of gamma choices.
Gamma 2.2 also provides a perceptually uniform tone range to the observer.
Gamma 1.8