Capture sharpening is best done during RAW file conversion. It must always be done after scanning of analog originals.
Capture sharpening typically is done globally and uniformly to all areas of an image, but on-the-fly masking routines are recommended to reduce or remove sharpening effects from low-frequency (smooth) image areas.
When performing capture sharpening, err on the conservative side and avoid producing unwanted artifacts. Don’t fall prey to the temptation to fix unwanted sharpening artifacts you could produce at this first stage of sharpening in subsequent stages of image editing; you’ll get better results if you don’t produce unwanted sharpening artifacts at all.
Noise-reduction practices will impact sharpening practices; reduce noise before sharpening.
Creative sharpening is potentially the most high-impact stage of sharpening. Even so, not all images need to be creatively sharpened. In high-productivity workflows, this stage of sharpening is typically abandoned, as it can’t be automated. Creative sharpening is generally reserved for images that merit additional care and consideration. The decisions made at this second stage of sharpening largely are subjective and based on the visual preferences of the individual doing the sharpening, not the characteristics of the tools used to produce an image.
The goal of creative sharpening is to give an image a specific look and feel. Creative sharpening can prioritize image information, guiding a viewer’s eyes in more specific ways, and enhance qualitative aspects of images to produce stronger responses. Used consistently, creative sharpening can produce a distinctive style to viewers. (Creative blurring also may be used in combination with creative sharpening to make the effect seem even stronger by comparison.)
Creative sharpening is done after RAW conversion (or scanning), typically in Photoshop, employing additional image layers to produce the most sophisticated results. Creative sharpening is most frequently applied selectively, varying the amount and/or type (Unsharp Mask, Smart Sharpen, High Pass, etc.) of sharpening in different regions of an image.
Capture sharpening needs to be determined visually, while previewing an image on a monitor at 100% screen magnification, again, the magnification that most precisely displays low-frequency detail such as texture and noise.