Edges, Surface & Fix Tabs

The values of the controls of the Edges and Surface tab sheets are automatically set by the Auto features. However, if you need finer control of the sharpening you can also use them directly. Changing the values of these controls will automatically deactivate the appropriate Auto feature(s) to avoid that the values are reset again. Additionally the Fix tab lets you reduce white and black halos.

Edges

The controls of the Edges tab sheet apply their values only to the edges in the image. With edges the lines that lie between two areas of different brightness and color are meant. If you imagine a photo as a pencil drawing, the black lines would represent the "edges".

The Sharpen slider determines the intensity of the sharpness effect that is applied to the edges. The Radius slider on the other hand lets you choose the size of the details that are emphasized in the edge areas. If you multiply the Radius value by 2 you get the pixel size of the affected details. Details that are smaller than the Radius * 2 will be sharpened to a smaller extent.

The Method box lets you choose between various sharpening methods. "Cosine" and "Circular" usually produce a slightly stronger sharpening effect than "Gaussian". "Linear" is similar to "Gaussian", but not that sophisticated. The default "Gaussian" option is usually the best choice.

With the Compensate check box activated you can avoids halos at higher Radius values. It is not recommended to deactivate it unless you want to produce halos or want to increase sharpness without caring about side effects. It also keeps the sharpness constant when changing the Radius slider. The auto features automatically activate this check box, so if you deactivate it, the auto features are deactivated, too.

The Antialias check box applies an antialias effect that removes grain and artifacts. By using this effect you can apply a stronger sharpening without making grain and artifacts visible. It can also be used to make oversharpened images less sharp.

Surface

The controls of the Surface tab sheet are very similar to those of the Edges tab sheet. However, they only apply an effect to the surface areas in the image. The surface consists of the uniform areas in an image which have a very similar color and brightness. If you imagine a photo as a pencil drawing, the white background would represent the "surface".

The Sharpen slider determines the intensity of the sharpness effect that is applied to the surface of objects. The Radius slider lets you choose the size of the details that are emphasized in the surface areas. If you multiply the Radius value by 2 you get the pixel size of the affected details. Details that are smaller than the Radius * 2 will be sharpened to a smaller extent.

The Soften slider which isn't available in the Edges tab lets you smooth the surface areas. This can help to reduce noise in these areas, to weaken a sharpening effect or to give the image a softer look. If both the Sharpen and Soften sliders have a value larger than zero, each will weaken the effect of the other. Nevertheless the effect of the slider with the larger value will prevail.

The Method box lets you choose between various sharpening methods. "Cosine" and "Circular" usually produce a slightly stronger sharpening effect than "Gaussian". "Linear" is similar to "Gaussian", but not that sophisticated. The default "Gaussian" option is usually the best choice. 'Median' should only be used in connection with the Soften slider, because of its rough effect.

With the Compensate check box activated you can avoids halos at higher Radius values. It is not recommended to deactivate it unless you want to produce halos or want to increase sharpness without caring about side effects. It also keeps the sharpness constant when changing the Radius slider. The auto features automatically activate this check box, so if you deactivate it, the auto features are deactivated, too.

Fix

The Fix tab sheet offers four sliders called "White Halo", "Black Halo", "Highlights" and "Shadows". The two Halo sliders let you reduce the intensity of too strong halos that are produced by the sharpening process. With their help you can produce a very strong sharpening effect without unwanted side-effects. These two sliders let you influence the white and black part of the halos independently. Usually white halos are more visible than black ones. Using too high values for both sliders can also reduce the sharpness of the edges in the image. In a few cases choosing very different values for both sliders may add an unnatural look.

The "Hightlights" and "Shadows" sliders lets you reduce the sharpening or blurring in the highlight and shadow areas. Using the "Highlight" slider you can make sure that the bright areas of the image aren't made even brighter by the sharpening effect. With "Shadows" slider you can avoid that noise is made visible by the sharpening, which brightened up the dark pixels. Additionally when applying a blur effect you have more control over the blurring with the help of these two sliders. Setting both sliders to their maximum values doesn't completely remove the sharpening or blur effect. The midtones are still affected slightly.

For more tips about halo reduction, please read the Tips page.