Dell IN1930 User Manual page 17

Brightness
Contrast
Allows you to adjust the brightness or luminance of the backlight.
Press the key to increase brightness and press the
Allows you to adjust the contrast or the degree of difference between darkness and lightness on the monitor screen. Adjust brightness first,
and adjust contrast only if you need further adjustment.
Press the key to increase contrast and press the
key to decrease brightness (min 0 ~ max 100).
key to decrease contrast (min 0 ~ max 100).