Microtek ScanMaker 6100 Pro User Manual page 89

Using the Brightness & Contrast tool:
Drag the scroll bar on the Brightness or Contrast control to change
the settings. Take note of the following:
Too much brightness can make an image look washed out,
while too little brightness will make the image look dark.
Too much contrast will make an image look like a photocopy of
a picture, with little or no gray shades left. Too little contrast
will make the colors in the image look dull and flat.