Extract scanned from one of my photography magazines on sharpening
The following information was taken from Adobe Help
http://helpx.adobe.com/photoshop-elements/using/sharpening.html [accessed on 10 January 2013]
Use the Unsharp Mask filter
The Unsharp Mask filter reproduces a traditional film technique used to sharpen edges in an image. The Unsharp Mask filter corrects blur introduced during photographing, scanning, resampling, or printing. It is useful for images intended for both print and online viewing.
Unsharp Mask locates pixels that differ from surrounding pixels by the threshold you specify and increases the pixels’ contrast by the amount you specify. For neighboring pixels within the specified radius, the lighter pixels get lighter, and the darker pixels get darker.
The effects of the Unsharp Mask filter are far more pronounced on‑screen than in high-resolution printed output. If your final destination is printed output, experiment to determine what settings work best for your image.
Unsharp Mask locates pixels that differ from surrounding pixels by the threshold you specify and increases the pixels’ contrast by the amount you specify. For neighboring pixels within the specified radius, the lighter pixels get lighter, and the darker pixels get darker.
The effects of the Unsharp Mask filter are far more pronounced on‑screen than in high-resolution printed output. If your final destination is printed output, experiment to determine what settings work best for your image.
The Unsharp Mask filter adds contrast to reduce fuzziness.
- In the Edit workspace, select an image, layer, or area.
- Choose Enhance > Unsharp Mask.
- Select the Preview option.
- Set any of these options and click OK:
Amount
Determines how much to increase the contrast of pixels. For high-resolution printed images, an amount between 150% and 200% is usually best.
Radius
Specifies the number of pixels to sharpen around edges. For high-resolution images, a radius between 1 and 2 is usually recommended. A lower value sharpens only the edge pixels, whereas a higher value sharpens a wider band of pixels. This effect is much less noticeable in print than on‑screen, because a 2‑pixel radius represents a smaller area in a high-resolution printed image.
Threshold
Determines how far different pixels must be from the surrounding area before they are considered edge pixels and sharpened. To avoid introducing noise (in images with flesh tones, for example), experiment with Threshold values between 2 and 20. The default Threshold value (0) sharpens all pixels in the image.
Exercise:
Take an image make 3 copies each one varying in a different degree of sharpening.
Exercise:
Take an image make 3 copies each one varying in a different degree of sharpening.
Original
mild changes
harsh changes