DarkAdapted is a software that allows you control gamma settings.

Here are some key features of "DarkAdapted":

• DarkAdapted is free of charge (but remains copyrighted by Stephen E. Hutson).
• Customizable gamma presets. Use predefined settings, create your own, and manipulate your presets with ease.
• High-resolution sliders allow you to adjust red, green, and blue video components individually and in real time.
• Small screen mode hides advanced controls, minimizing the use of valuable screen real estate. The Main Window may also be hidden entirely.
• Select a preset by typing the first few letters of its name.
• Export and import gamma presets to and from disk files. Sample presets files are included with the download.
• Full AppleScript support (on Mac OS), including a sample AppleScript with the Mac OS download.
• “Gama Toggle” keys offer a quick return to full brightness. Modifier keys are full assignable.
• Switching to gamma presets is performed via smooth fades, never abrupt shifts in screen color or brightness.
• Gamma fade duration is user-configurable (from instantaneous to two seconds), and slider controls may be set to update in real time during the fade.
• Control console “remembers” its position on your screen.
• Saved gamma preset is restored when DarkAdapted is launched, and reset when DarkAdapted quits.
• Manual refresh preference can override gamma adjustments made by screen savers or other software
• Automatic or manual checking for updates via the Internet.
• Useful display features show gamma changes’ effects on selected text, as well as text on different backgrounds.
• Useful numeric and graphical readouts of gamma values.
• Includes the same powerful night vision technology as ScopeDriver, a full featured telescope control program.
• And many other time savers and productivity enhancers.