Operation Manual

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The Tool Chest — Curves

White-Point and Black-Point Input Levels

Input levels for the white point and black point can be set

using any of the following three methods:

• automatic contrast adjustment

• white-point and black-point sliders

• direct sampling using the white-point and black-point

eyedropper tools

Automatic Contrast Adjustment

In automatic contrast adjustment, Nikon Scan automati-

cally selects white and black points that exclude a certain

percentage of the brightest and darkest pixels in the image,

steepening curves for enhanced contrast (the exact percent-

age of pixels excluded can be speciﬁ ed in the “Preferences”

dialog). By default, 0.5% of the brightest and darkest pixels

are excluded, producing a curve that makes optimal use of

the output tone range while preserving details in shadows

and highlights.

To perform an auto contrast operation, click the

but-

ton. The white and black points for each of the red, green,

and blue channels will be modiﬁ ed simultaneously and the

master curve will be displayed in the “Curves” palette (the

master curve itself is unaffected by this operation). Clicking

the

button with the Ctrl (Win dows) or option (Macintosh)

key held down adjusts contrast only for the channel cur rent ly

se lect ed in the channel menu.

To modify brightness and contrast without affecting color

balance, select the master channel and click the

button

while pressing Ctrl (Win dows) or option (Macintosh).