Adobe 13102498 - Photoshop CS3 - Mac User Manual page 215

• Sharpening increases image contrast. If you find that highlights or shadows are clipped after you sharpen, use the
layer blending controls (if you sharpen a separate layer) to prevent sharpening in highlights and shadows. See
"Specify a tonal range for blending layers" on page 296.
• If you need to reduce image noise, do so before sharpening so that you don't intensify the noise.
• Sharpen your image multiple times in small amounts. Sharpen the first time to correct blur caused by capturing
your image (scanning it or taking it with your digital camera). After you've color corrected and sized your image,
sharpen it again (or a copy of it) to add the appropriate amount of sharpening for your output medium.
• If possible, judge your sharpening by outputting it to the final medium. The amount of sharpening needed varies
among output media.
For greatest control use the Unsharp Mask (USM) filter or the Smart Sharpen filter to sharpen your images.
Although Photoshop also has the Sharpen, Sharpen Edges, and Sharpen More filter options, these filters are
automatic and do not provide controls and options.
You can sharpen your entire image or just a portion defined by a selection or mask. Because the Unsharp Mask and
Smart Sharpen filters can be applied to only one layer at a time, you might need to merge layers or flatten your file
to sharpen all image layers in a multilayered file.
Note: Don't be misled by the name Unsharp Mask, which comes from a darkroom technique used in traditional
film-based photography. The filter sharpens images rather than the opposite.
Sharpen using Smart Sharpen
The Smart Sharpen filter has sharpening controls not available with the Unsharp Mask filter. You can set the sharp-
ening algorithm or control the amount of sharpening that occurs in shadow and highlight areas.
1 Zoom the document window to 100% to get an accurate view of the sharpening.
Choose Filter > Sharpen > Smart Sharpen.
2
3 Set the controls in the Sharpen tabs:
Sets the amount of sharpening. A higher value increases the contrast between edge pixels, giving the
Amount
appearance of greater sharpness.
Determines the number of pixels surrounding the edge pixels affected by the sharpening. The greater the
Radius
radius value, the wider the edge effects and the more obvious the sharpening.
Sets the sharpening algorithm used to sharpen the image. Gaussian Blur is the method used by the Unsharp
Remove
Mask filter. Lens Blur detects the edges and detail in an image, and provides finer sharpening of detail and reduced
sharpening halos. Motion Blur attempts to reduce the effects of blur due to camera or subject movement. Set the
Angle control if you choose Motion Blur.
Sets the direction of motion for the Motion Blur option of the Remove control.
Angle
Processes the file more slowly for a more accurate removal of blurring.
More Accurate
Adjust sharpening of dark and light areas using in the Shadow and Highlight tabs. (Click the Advanced button to
4
display the tabs). If the dark or light sharpening halos appear too strong you can reduce them with these controls,
which are only available for 8-bits and 16-bits-per-channel images:
Adjusts the amount of sharpening in the highlights or shadows.
Fade Amount
Controls the range of tones in the shadows or highlights that are modified. Move the slider to the left
Tonal Width
or right to decrease or increase the Tonal Width value. Smaller values restrict the adjustments to only the darker
regions for shadow correction and only the lighter regions for highlight correction.
PHOTOSHOP CS3 208
User Guide