Dell S2230MX User Manual page 21

Brightness Allows you to adjust the brightness or luminance of the backlight.
Press the
Contrast 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
Auto Adjust
Use this key to activate automatic setup and adjust menu. The following dialog appears on a black screen as the monitor self-adjusts to
the current input:
key to increase brightness and 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).