Microtek ArtixScan 4500t Reference Manual page 92

You can use the Black and White Eyedropper tools to define the Dmax (darkest
tone) and the Dmin (lightest tone) settings, respectively.
To do this: Click the Eyedropper tools in the Dynamic Range dialog box. Then
move to the thumbnail image in the dialog box or to the preview image in the
Preview window, and choose your Dmax / Dmin point.
• To define the Dmax (darkest tone) setting, use the Black Eyedropper tool.
• To define the Dmin (lightest tone) setting, use the White Eyedropper tool
Black
Eyedropper for
Dmax settings
Reference: The Advanced Image Correction tools
Enable this
check box to
show the
adjustment
effect on the
prescan image
White
Eyedropper for
Dmin settings
85