Photo RGB Expert Controls
Tone & Cast
The RGB Expert Controls give the user the ability to correct using gradation and color curves.
Every original, film or print, has a specific density range which defines the points where the image
data starts and ends. This density range is measured on an optical density scale of 0 (lowest) to 4
(highest). The “output density range” is usually set to different values than the input range. The
default output density value is 2.7, which is the maximum value that modern CRT monitors are capa-
ble of displaying. Knowing the density range of your intended output device and using that value in
the RGB control window helps optimize the quality of the final image.
The density range of an image can also be set manually. This is done by adjusting the RGB curves
for the image in the Tone & Cast section of the RGB Control window. The purpose of the tone
curves is to define what is neutral by removing unwanted casts, and to specify tone compression
and contrast using the gradation curve. Therefore, color correction should only be performed in the
Selective Color window, where neutrals and hues are treated separately.
To adjust neutral tones, use Tone & Cast; to adjust hues, use Selective Color.
UMAX PowerColor Quick Start Guide
Photo RGB Expert Controls
9
Summary of Contents for PowerColor
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