The purpose of this thread is to learn everything there is to know about Capture NX's Unsharp Mask (USM). It is very different from Photo Shop's USM, which is particularly important for those of us who migrated from Photo Shop to Capture NX. Feel free asking questions and providing answers. This first post is a general collection of resource materials that I'll update as we become aware of new information. Capture NX 2 User Manual Click here to access the manual. Sharpening Tips in Tutiki http://tutiki.org/w/index.php/Nikon_NX_Sharpening_Tips Capture NX Help Screens about USM GENERAL DESCRIPTION OF USM "The Unsharp Mask tool increases the apparent sharpness of your images by enhancing the edges of objects in your image. The Unsharp Mask tool in Capture NX 2 is unique in that it always applies its sharpening to the luminosity of the image, which prevents any unwanted color shifts." COMPARISONS WITH PHOTO SHOP'S USM "Unsharp Mask sharpens edges without affecting color balance by making adjustments only to luminosity (brightness). The effect is the same as performing Unsharp Mask with the Luminosity channel selected in the Adobe Photoshop Lab color model. If Unsharp Mask is applied to a single channel, such as red, the values for ab (chrominance) are used to determine what points in the image are red, and masking applied to the Luminosity channel for those points only. An intensity of around 20% in Capture NX 2 is roughly equivalent to 100% in Adobe Photoshop. No sharpening will be applied if Intensity is set to zero. Intensity must be set to at least 1% if sharpening is to apply." INTENSITY PARAMETER "The Intensity slider controls the amount of sharpening that will be applied to the color selected by the Color pull-down menu. The higher the sharpening intensity, the more pronounced the sharpening effect will be on your image. If the intensity setting is set too high, it can create an over-sharpened and artificial looking image." RADIUS PARAMETER "The Radius slider enables you to increase the reach of the sharpening effect. The higher the radius setting, the wider the edges will appear in the sharpen image. A radius setting that is too high will produce visible halo artifacts, which can appear as white outlines around objects." THRESHOLD PARAMETER "The Threshold slider is designed to limit where sharpening is applied with the current settings. The higher the threshold setting, the less that objects in the image will be sharpened. This slider works to indicate how much of a difference between one pixel and its neighbors is necessary in order to apply sharpening. This slider is helpful in preventing smooth areas from picking up noise artifacts, such as when sharpening skin areas or landscapes with large amounts of sky. Too high a threshold setting will prevent any objects from being sharpened in the image, so it is important to find a good balance."