Furuno GP-3500 - Manual (Page 16)

1. BASIC OPERATION
1-6
1.4 Adjusting Brilliance and Hue
You can adjust display brilliance, panel dimmer and hue as shown below.
1.4.1 Adjusting display brilliance
1. Press the [BRILL] key.
The brilliance adjustment window appears.
TURN KNOB TO ADJUST DISPLAY BRILLIANCE.
BRILLIANCE 8
Brilliance adjustment window
Note: The adjustment window disappears when there is no operation for three
seconds.
2. Rotate the [ENTER] knob to adjust the brilliance.
Rotate clockwise to raise the setting or counterclockwise to decrease it (8 steps).
Also you can adjust brilliance by pressing the [BRILL] key. In this case brilliance
is changed cyclically 1→2
… →8→7→ … 1→2 … .
3. Press the [ENTER] knob to manually close the adjustment window, or wait
three seconds to let the equipment close it automatically.
Note: The brilliance of an external monitor cannot be adjusted from the display
unit. Adjust it at the external monitor.