Operation Manual

About Hue, Saturation, and Luminance
Hue (H) describes the actual color itself. Hue is measured as an angle on a color wheel.
Moving a Hue slider in Aperture remaps the color from its original position on the color
wheel to the new position indicated by the slider. Hue adjustments are often made to
match the color of the same subject in different images. Adjusting the hue of an image
is particularly useful when the subject you shot moved between various lighting
conditions. Another advantage of adjusting the hue of an image is that camera models
of different types or from different manufacturers rarely capture and render color exactly
the same way. You can use the Hue controls to match the color of a subject shot by
two different cameras, so that when the images are placed side by side, they match.
Saturation (S) defines the intensity of a specific hue. A saturated hue gives the color a
vivid and pure appearance. A less saturated hue appears flatter and more gray. A
completely desaturated hue becomes a shade of gray.
Luminance (L) describes the brightness of the selected color. An increase in luminance
brightens the selected color value. A maximum Luminance adjustment results in pure
white. Conversely, a decrease in luminance darkens the selected color. A minimum
Luminance adjustment results in pure black.
L
S
H
566 Chapter 17 Making Image Adjustments