15-27190-01004-03 Rev. B Garmin GTN 625/635/650 Pilot’s GuideForewordGettingStartedXpdr CtrlCom/NavFPLDirect-ToProcWpt InfoMapTrafficTerrainWeatherNearestMusicUtilitiesSystemMessagesSymbolsAppendixIndex15.8 Backlight SettingsThe backlighting of the display and bezel keys can be adjusted automaticallyor manually. The default setting (automatic backlighting adjustment) usesphotocell technology to automatically adjust for ambient lighting conditions.Photocell calibration curves are pre-configured to optimize display appearancethrough a broad range of cockpit lighting conditions. A manual offset createsa deviation form the normal curve. Manual adjustments may be made from+100% to -10%. The negative adjustment is limited to prevent the backlightfrom being accidently decreasing the backlight to the point where the display ofinformation could not be seen.Manual backlighting adjustment can be accomplished using the existinginstrument panel dimmer bus or the following procedures.1. While viewing the System page, touch the Backlight key.Backlight Level.Touch Arrows To SetManual OffsetFigure 15-37 Backlight Level Setting2. Touch the Manual Offset Arrow keys to set the ManualOffset level.3. After making the desired selections, touch the Back key toreturn to the Setup page.
