3.3

Chapter 17 Making Image Adjustments 373
Working with the Color Controls
An Overview of the Color Adjustment
You use the Color adjustment controls to selectively adjust the red, green, blue, cyan, magenta,
and yellow colors in an image. Each color has individual Hue, Saturation, and Luminance controls.
If you need to adjust the hue, saturation, and luminance of a color that does not appear in the
Color controls, you can use the Color eyedropper to identify a hue in the image that needs
adjusting.
Although segmenting control of hue, saturation, and luminance on a per-color basis may seem
complicated at rst, restricting these adjustments to specic colors helps correct and enhance
targeted colors without aecting others. In addition, Aperture provides Range controls used to
set the extent of colors aected by the Hue, Saturation, and Luminance adjustments. The extent
of colors aected by these adjustments is also known as chromatic spread. You use the Range
controls to ne-tune your color adjustments.
Before Color adjustment
After Color adjustment
(adjusted the hue and
saturation of blue)
You can also brush the Color adjustment on selected parts of an image. For more information,
see An Overview of Brushed Adjustments on page 388.
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 dierent 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 dierent types or from dierent 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 dierent cameras, so that when the images are placed side by side, they
match.
Saturation (S) denes the intensity of a specic hue. A saturated hue gives the color a vivid and
pure appearance. A less saturated hue appears atter and more gray. A completely desaturated
hue becomes a shade of gray.