RGBlink VSP 628S User Manual page 108

Step 7: Image contrast setting, it is mainly for output image contrast. If
"Sync" is grey, you can adjust one color alone, when "Sync" is green, it
means it starts, drag one color, and the other two color values will change
accordingly to the same value.
Note
VSP 628S
User can adjust setting according to actual
condition, the function mainly suitable for the
personage that is very processional in image
quality. Nonprofessional isn't recommend to the
above operations, if distortion of image quality as of
improper operation errors, you can reset to the
factory initialization.
User Manual 108