Using a sharpening workflow in Photoshop CS2
Table of Contents
Sharpening brushes
For localized creative sharpening, nothing beats painting with a brush. We have two methods that we use to make a “sharpening brush,” one using a layer, the other using History. Layer-based brushes offer more control because you can control the local opacity of the layer mask by brushing with different opacities, and you can control the global strength of the sharpen by varying the opacity of the layer itself. However, layers increase your file size. Using the History brush is less controllable (because your only control is through the brush opacity itself ) but doesn’t add to the size of the file. Keeping your file size down is important when you’re working with huge files.
Layer-based sharpening brush. To create a layer-based sharpening brush, first make a sharpening layer as we showed earlier in Figure 1. It’s usually a good idea to apply slightly more sharpening to the layer than you ultimately desire, because that way you have more control after the fact. Next, add a layer mask set to Hide All. To brush in the sharpening, make sure that the layer mask is targeted, then choose the Brush tool, set the foreground color to white, and simply brush the sharpening in as desired. We prefer to use a brush set to substantially less than 100 percent opacity, because the lower opacity allows us more control. Figure 5 shows the results of a sharpening brush.
Figure 4: Controlling the tonal range. The Blend If sliders let us focus sharpening on the midtones.
Unsharpened
Before blending tweak
After blending tweak
Here, the top sliders fully apply tonal values between level 65 and 200, and gradually feather values from 65–20 and 200–245. The bottom sliders protect the underlying values below 20 and above 245, and feather the adjustment to values between 20 and 40, and 230 and 245. The result is that the contrast of the dark and light sharpening halos is reduced, allowing headroom for subsequent creative or output sharpening.
Figure 5: A layer-based sharpening brush
The unsharpened image
The unmasked sharpening layer (before choosing Hide All)
The unmasked sharpening layer
The sharpening brushed in locally on the mask
The brushed layer mask
History Brush sharpening. If you’re too lazy to create masks, you’re in a RAM-limited situation, or if you just want more interactivity than a mask offers, you can use the History Brush to paint sharpening into the image. This is a particularly handy technique with a pressure-sensitive stylus, because you can set the pressure-sensitivity to Opacity, and achieve fine control over both the strength of the sharpening, and exactly where it’s applied.
The basic technique is a simple three-step process:
- Apply the Unsharp Mask filter.
- Set the History state to the step before you applied Unsharp Mask, and the source for the History brush to the Unsharp Mask step.
- Paint the sharpening into the image as desired.
Or, if you prefer, you can reduce the sharpening with the History Brush by leaving the History state at the Unsharp Mask step, and then loading the step before it as the History Brush source. We typically choose the method that will require least brushwork on the image at hand.
The unsharpened image in Figure 6 is quite soft. (No, this isn’t David or Bruce’s child!) If we apply enough sharpening to pick up the texture in the fabric, it leaves the skin crunchy, which is bad at the best of times, but particularly so on babies!
Figure 6: Global sharpening makes crunchy skin
The unsharpened image
The image sharpened globally
In this case, it’s much less work to set the History Brush source to the unsharpened state, and brush out the crunchies than it would be brush them in. A few quick strokes with a soft, low-opacity History Brush produce the much more pleasing rendition shown in Figure 7.
Figure 7: History Brush sharpening
Taking the globally sharpened image as the starting point, we set the source for the History Brush to the unsharpened state, and brush out the crunchies.
The image after History brushing
Tip: Luminosity Sharpening with History. Earlier you saw that you can perform luminosity sharpening by selecting Fade from the Edit menu after running the Unsharp Mask filter (and setting the blending mode in the Fade dialog box to Luminosity). If you’re brushing sharpening in rather than out, you can do the same thing by setting the blending mode for the History Brush to Luminosity using the Mode popup menu in the Options bar.
Where to go from here
For more information about Photoshop CS2 and photo editing techniques, check out the following articles:
- Advanced sharpening techniques by Mark Galer and Phillip Andrews
- Adobe Photoshop CS2 Classroom in a Book* by the experts at Adobe
- Adjustment layer basics* by Bruce Fraser and David Blatner
