Operation Manual

Adjusting the Radius of the Highlights & Shadows Controls
You use the Radius parameter controls to adjust the area around each pixel that Aperture
uses to assess the tonal area that each pixel inhabits. The larger the Radius value is, the
larger the area used to determine each pixel’s tonality. The Radius controls can have a
large impact on the behavior of the Highlights & Shadows controls, because the Radius
controls either increase or decrease the range of pixels used to determine how light or
dark each individual pixel should be.
To adjust the radius of the Highlights & Shadows controls
1 If necessary, click the Advanced disclosure triangle to show the advanced Highlights &
Shadows controls in the Adjustments inspector or the Adjustments pane of the Inspector
HUD.
Use the Radius slider and
value slider to adjust the
area used to determine
a pixel’s tonality.
2 Adjust the Radius parameter by doing one of the following:
• Drag the slider to the right to increase the radius of the area Aperture uses to assess
whether the pixel requires a Highlights or Shadows adjustment, and drag the slider
back to the left to reduce the radius.
• Click the left or right arrow in the Radius value slider to adjust the radius incrementally,
or drag in the value field.
The left arrow reduces the radius of the pixel area, and the right arrow increases it.
• By default, the Radius value slider is set to 200.00. Double-click the number in the Radius
value slider, then enter a value from 1.0 to 1000.0 and press Return.
Aperture uses the new Radius setting to determine each pixel’s tonality in relation to the
pixels that surround it.
532 Chapter 17 Making Image Adjustments