Edge masks target only the contours in an image. (Think of edge masks in Photoshop as the creative sharpening equivalent to the Masking slider in ACR or Lightroom’s capture sharpening.) They keep smooth areas smooth, while accentuating the contrast/sharpness of contours. They can be particularly useful for images that contain moderate to significant amounts of noise. In many cases, they allow the use of more aggressive applications of sharpening effects. Edge masks can help you take all of the creative sharpening effects you design up a notch – or two.