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Sharpen using smart sharpen, Sharpen using unsharp mask – Adobe Photoshop CS4 User Manual

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USING PHOTOSHOP CS4

Retouching and transforming

Last updated 1/10/2010

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
sharpening 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.

2

Choose Filter

> Sharpen

> Smart Sharpen.

3

Set the controls in the Sharpen tabs:

Amount

Sets the amount of sharpening. A higher value increases the contrast between edge pixels, giving the

appearance of greater sharpness.

Radius

Determines the number of pixels surrounding the edge pixels affected by the sharpening. The greater the

radius value, the wider the edge effects and the more obvious the sharpening.

Remove

Sets the sharpening algorithm used to sharpen the image. Gaussian Blur is the method used by the Unsharp

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.

Angle

Sets the direction of motion for the Motion Blur option of the Remove control.

More Accurate

Processes the file more slowly for a more accurate removal of blurring.

4

Adjust sharpening of dark and light areas using in the Shadow and Highlight tabs. (Click the Advanced button to
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:

Fade Amount

Adjusts the amount of sharpening in the highlights or shadows.

Tonal Width

Controls the range of tones in the shadows or highlights that are modified. Move the slider to the left 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.

Radius

Controls the size of the area around each pixel that is used to determine whether a pixel is in the shadows or

highlights. Moving the slider to the left specifies a smaller area, and moving it to the right specifies a larger area.

5

Click OK.

Sharpen using Unsharp Mask

The Unsharp Mask sharpens an image by increasing contrast along the edges in an image. The Unsharp Mask does
not detect edges in an image. Instead, it locates pixels that differ in value from surrounding pixels by the threshold you
specify. It then increases the contrast of neighboring pixels by the amount you specify. So, for neighboring pixels the
lighter pixels get lighter and the darker pixels get darker.