Apple Color 1.0 - Manual (Page 190)

190 Chapter 9 Primary In
Color balance controls are usually faster to use when making broad adjustments to the
shadows, midtones, and highlights of the image. Curves, on the other hand, often take
more time to adjust, but they allow extremely precise adjustments within narrow tonal
zones of the image, which can border on the kinds of operations typically performed
using secondary color correction.
Important: While the power of curves can be seductive, be wary of spending too much
time finessing your shots using the curves controls, especially in client sessions where
time is money. It’s easy to get lost in the minutiae of a single shot while the clock is
ticking, and such detail work may be faster to accomplish with other tools.
How Curves Affect the Image
Curves work by remapping the original color and luma values to new values that you
choose, simply by changing the height of the curve. The X axis of the graph represents
the source values that fall along the entire tonal range of the original image, from black
(left) to white (right). The Y axis of the graph represents the tonal range available for
adjustment, from black (bottom) to white (top).
Without any adjustments made, each curve control is a flat diagonal line; in other
words, each source value equals its adjustment value, so no change is made.
Source Value
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