Operation Manual

3 Do one of the following:
• Choose RGB from the Channel pop-up menu.
Choosing the RGB tonal curve allows you to manipulate the tonal curve of the red,
green, and blue color channels combined. This is the proper choice when you want to
modify the tint of the image in addition to the contrast.
• Choose Luminance from the Grayscale section of the Curves Action pop-up menu, then
choose Luminance from the Channel pop-up menu.
Choosing the luminance tonal curve allows you to manipulate the luminance of the
combined red, green, and blue color channels without affecting the image’s tint.
4 Choose the tonal range to display from the Range pop-up menu.
For more information about the options in the Range pop-up menu, see An Overview of
the Curves Adjustment Controls.
5 Choose the type of tonal curve adjustment to apply to the image from the Type section
of the Curves Action pop-up menu.
Choosing Linear—the default option—applies the Curves adjustment to the image evenly
from pure black to pure white and beyond. Choosing Gamma-Corrected applies the
Curves adjustment logarithmically to match the way the human eye perceives light,
adding additional weight to the shadows.
6 Drag the Black Point and White Point sliders to where they touch the outside of the
histogram graph, constraining the image to its new black and white points.
Drag the Black Point and
White Point sliders to where
they touch the outside of
the histogram graph.
544 Chapter 17 Making Image Adjustments