User guide

Using the Color Wheel to manually adjust color

To manually neutralize a color cast, such as a yellow scene caused by indoor lighting, use the loupe in the

Review Window to sample a color that represents a neutral gray. Based on the RGB values in the loupe,

drag the target ring in the color wheel to set the CMY values so that the RGB values will equalize. Since

the sampled color was known to be neutral, this generally balances the overall color of the image.

The value of the target ring is represented by units of cyan, magenta, and yellow recorded below the color

wheel, displayed in “CC” (color correction filter units). The chart on the preceding page indicates the

relationship between red, green, and blue, and cyan, magenta, and yellow.

If you feel the image has an overall color cast, and do not have a neutral color to sample, drag the target

ring in the opposite direction of the unwanted color to neutralize. For example, if the image appears too red,

move the target ring towards cyan, on the opposite side of red in the Color Wheel.

Using the Color Adjustment Eyedropper to adjust color

Use the Color Adjustment Eyedropper to let SIGMA Photo Pro create neutral gray tones in

your image. Locate a portion of your image in the current Review Window that includes a

known neutral color that is not rendered as a neutral color. Click on the eyedropper button.

The pointer turns to an eyedropper.

Place the eyedropper over the color to be neutralized and click. The

software will evaluate that sample and make adjustments to achieve a

neutral tone. You can also click and drag the color picker and the

software will continue to sample and adjust until you release the mouse.

Once you have clicked on the neutral tone, click the

eyedropper button to return to the original loupe or

pointer.

Note in this example that the known neutral gray

square was weak in Blue. Once balanced, the Blue

value increased from 127 to 211, and the gray now

appears neutral as in the original scene.

Before

After adjustment

If you are viewing the image in the Review Window using the loupe, notice that the RGB values in the

neutral area are exactly equal to each other, or nearly exact, after the adjustment.

If you wish to redo the gray balance using a different sample point, click on the eyedropper button and

repeat the steps above.

If you do not like the results of the color adjustment, click on the Reset button at the bottom of the panel to

return to default (no color adjustment) setting. You can also use the eyedropper adjustment as a base, and

then move the target ring in the color wheel to refine your adjustment.

SIGMA Photo Pro User Guide 31