In our sharpening workflow, we use combinations of all the techniques covered in the previous section. In this section, we'll describe briefly how we incorporate these techniques into a sharpening workflow.
If we're working on images from scratcheither from a film scan or from a digital capturewe use two or three sharpening passes, as described in "When We Sharpen," earlier in this chapter. When we have to deal with files that already have had some sharpening applied, we deal with them on a case-by-case basis. If we feel that they're adequately sharp, we may do no additional sharpening, or we may apply localized creative sharpening. If we have to resize the image for output, we'll almost certainly do a global sharpen after resize, tailored to the output process.
The First Sharpening Pass
Our first sharpening pass aims to compensate for the shortcomings of the capture in a way that's sensitive to the image content. We do so by creating a sharpening layer, applying an edge mask, sharpening with a radius that matches the image content, then constraining the tonal range to the midtones using the Blend If sliders in Layer Style.
The result is a subtle sharpen that makes the image behave better through resizing and through the subsequent sharpening phases. If the image has already had sharpening applied, we omit this step. We usually apply this sharpen after we've made our initial global adjustments for tone and contrast, because major contrast moves afterwards may defeat the sharpening. If file size is a concern, we may flatten the image after we've fine-tuned the initial sharpen.
If noise reduction is required, we'll do it before sharpening, either running Despeckle through a mask, or running Reduce Noise on its own merged layer. When extreme noise reduction is required, we'll apply a mask to the noise reduction layer to protect the edges.
For localized creative sharpening, we generally use some variant of the sharpening brush techniques. We apply creative sharpening after we've fine-tuned the tone and color both globally and locally, because changes to contrast and color can easily affect the perceived sharpness.
We apply output sharpening globally, using a sharpening layer with no layer mask. For halftone and inkjet outputs, we often use the Hard Light/High Pass sharpening technique. Output sharpening must be done at final output resolution. If you think it's likely the image will be resized after it leaves your hands, we advise omitting the output sharpening stepanyone who resizes the image will probably resharpen anyway, and if you've done a reasonably good job in the capture and creative phases, the final result will still be sharp.
The key difference between output sharpening and the earlier phases is that more often than not we produce a result that looks downright scary on the monitor. Keep in mind the physical size of the sharpening halo on output. Light and dark contours that are 3 pixels wide may look hideous on the monitor; but if you're printing at 300 ppi, they'll translate into contours (light and dark parts of the sharpening halo) that are only of an inch wide, so they won't be obvious on the final print.
Attempting to show the apparent on-screen sharpness in print is a very uncertain endeavor. What we've attempted to do in Figure 9-18 is to show the image pixels at 200-percent view through the various phases of sharpening, along with the final printed image at print size, in the hope that doing so will give you some idea of the relationship between what happens to the pixels themselves and the influence on the final printed result.
Figure 9-18. The sharpening workflow
Obviously, the on-screen appearance at Actual Pixels will vary dramatically over different display types and resolutions, but as you zoom in, the differences between display types become much less significant. We hope that the figure at least demonstrates the dramatic differences in halos created by the capture and creative sharpening phases, and those created by the final output sharpening. To help understand what you're seeing, we've also noted the sharpening settings we used for each step of the sharpening process, from capture through to final output.
Output sharpening is the only phase that easily lends itself to a formula, because once the image has been sized and the output process chosen, the physical size of the pixels, and hence of the sharpening halos, is a known quantity. For the capture and creative phases of the sharpening workflow, common sense, good taste, and in the long run, experience are the best guides!