Specifications

ptg
231
Performing Automatic Color Corrections
Removing a Color Cast Using ChromaWheels
Yo u c an a l s o r e m ov e a c o lo r c as t s e mi a ut o m at ic a ll y b y c li ck i n g a R e mo v e
Color Cast button and using its eyedropper to identify an image
area that you want to make color neutral (black, white, or neutral gray). Think
of this operation as an “assisted automatic” function since you use the eye-
dropper to direct the system to the area you want to correct. The Remove
Color Cast buttons appear below each of the three ChromaWheel controls,
and adjustments are made only to that wheel. Only the parts of the image
that fall within the luma range controlled by that wheel are changed.
Remove Color Cast buttons provide more precise control over color cast
removal than Auto Balance buttons, because when you use the eyedrop-
per, you are telling the system where to “look.”
To select which ChromaWheel control to adjust based
on the luma level of the area you want to identify:

To make white or l ight gray areas of a n ima ge c olor neutr al a nd re move
a cast throughout the lightest part of the image, click the Remove
Color Cast button below the Highlights ChromaWheel control.

To make midgray areas o f an image color neutral a nd r emove a cas t
throughout the midtones of the image, click the Remove Color Cast
button below the Midtones ChromaWheel control.

To make black or dark gra y are as o f an image color neut ral and r emove
a cast throughout the darkest parts of the image, click the Remove
Color Cast button below the Shadows ChromaWheel control.
Sampling Colors to Determine Color Cast
If you want to measure a color to determine its levels of red, green, and
blue, you can use the Color Match controls. Measuring a color to gauge its
individual color channels is a great way to determine whether a particular
color exhibits a color cast.
NOTE This operation
is not suitable for flesh
tones because they are
not color neutral and are
located in the red-yellow
color range.
NOTE The standard
method of color cor-
rection applies here.
Before you eliminate
a color cast, adjust the
image luma, manually
or automatically. Doing
so defines the range
in which the correction
takes place.
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