Creative sharpening is the catch-all term for localized adjustments to image detail. Unlike optimizations for capture and output processes, creative adjustments can’t be applied automatically based on specific parameters—they require creative judgment, hence the name.

But automation plays an important role in making many of the tools we use for creative sharpening. The only part of the process that can’t be automated is the actual localizing of an effect to a specific area of an image. So in this section we’ll discuss building creative sharpening (and blurring) tools and applying them effectively to images in Photoshop. The first valuable lesson to learn is that you can turn any adjustment into a brush!

You can turn any adjustment into a brush using three simple steps:

• Make the adjustment on a separate layer—usually you’ll create the layer using Option-Merge Visible, then apply the adjustment globally to the entire layer.
• Add a layer mask set to Hide All—that is, solid black. The easiest way to do this is to Option-click the “Add layer mask” button in the Layers palette. This hides the effect.
• Select the brush tool with the desired size, hardness, and opacity, and paint with white on the layer mask to reveal the effect. This deceptively simple technique offers very precise control over localized sharpening. As long as the layer has a layer mask, you can paint the effect in or out depending on the color you paint onto the mask. You can start with an all-white or all-black mask, which we’ll show you next.

The illustration below shows an image that has a Midtone Contrast effects layer created as the top layer. To localize the effect, we’ll add a layer mask.

Adding a layer mask. Image with Midtone Contrast layer (left). Layers panel showing Add layer mask button (right).

The question is whether to add a “reveal all” mask or a “hide all” mask, as shown below.

Creating a hide all or reveal all layer mask. A hide all mask (top). A reveal all mask (bottom).

Whether you add a hide all or reveal all mask is really dependent on how you want to get to where you want to end up. Either mask can produce the same results once you’re done editing the final mask. The real question is which approach will get you to your final result the quickest. If the effect you want to add needs a gentle addition and will be kept in relatively smaller localized areas, we suggest creating a hide all mask. This allows a slow build-up of the effect by addition rather than subtraction. The illustration below shows the addition of the effect by painting white gently into the hide all mask.

Painting an effect into a layer mask. Brushing in white with the mask targeted (top). Resulting layer mask with white added to the mask (bottom).

One word of caution when painting into layer masks: Make very sure you have actually targeted the layer mask and not the pixel layer before starting to paint. We can’t tell how many times we’ve failed to make sure and ended up painting into the pixels instead of the mask. Since Photoshop can’t know in advance what your true intentions are, it’s really up to you to make sure you do the right thing. The next illustration shows using the other alternative approach of painting out an effect.

Painting out an effect on a layer mask. Brushing in black with the mask targeted (top). Resulting layer mask with black added to the mask (bottom).

You don’t have to do everything with the brush, though it’s often easiest. The goal of brushing is to localize the effect and to obtain the desired relative strength of the effect within the brushed area. In addition to black and white brush strokes, you have two other important controls over the effect:

• You can increase or reduce the layer opacity as a master control over the strength of the effect.
• You can make tonal edits to the layer mask using Levels or Curves to adjust the way the effect is applied locally.

As you work the mask, regardless of what flavor you started with, you can toggle back and forth between white or black (the foreground and background colors) by pressing the X key.

We tend to paint on masks with a rather low opacity or flow. You are not restricted to using only a paintbrush to modify the layer mask; you can use any selection tool and fill with black or white. You can also run filters over the layer mask such as a Gaussian Blur to soften the mask.

Most of the techniques we’ll be covering in this section are designed to be used locally and often in very low doses, as some are “industrial strength.” Use these techniques with a degree of subtlety.

Depth-of-Field Brush

You can’t really counteract insufficient depth of field (DOF) any more than you can make out-of-focus elements in focus. But you can produce a reasonable illusion by using the following technique, which combines Unsharp Mask and Overlay/High Pass sharpening.

We start the process by making a sharpening layer set to Overlay blend with a 50% opacity and the Blend If options set to roll off highlights and shadow. We’ll run an Unsharp Mask at an Amount of 200% and a Radius of 2.5 followed by a High Pass filter at a radius of 30 pixels.

The illustrations below show the creation of the sharpening layer, the application of the filters, and the addition of a layer mask set to hide all. The last figure shows the final painted layer mask.

Building a depth-of-field sharpening layer. Creating a sharpening layer at the top of the layer stack. Blend If slider settings. Creating a hide all layer mask for the DOF layer after the filters have been run. The final layer mask showing the areas sharpened in white.

The effect is something between conventional sharpening and a midtone contrast boost. It’s often quite difficult to see the effect while you’re painting it in, but turning the layer on and off makes it quite obvious. This doesn’t take the place of proper focusing but, in a pinch, can increase the apparent sharpness of areas within an image. The illustrations below shows the before and after with detail crops.

Contact-print-size crop before DOF brush (left). Before detail at 300% zoom view (right). Contact-print-size crop after DOF brush (left). After detail at 300% zoom view (right).

Haze-Cutting Brush

The haze-cutting brush is a variant of the depth-of-field brush that’s useful for bringing distant elements in landscapes closer. It uses the same techniques as the DOF brush, but incorporates a cooling step after creating the sharpening layer. While we used the same numbers for the Unsharp Mask and High Pass filters in this example as we did in the previous example, feel free to play with different amounts and different blends. This is, after all, a creative process. Once you get a formula you like, create an action so you can achieve the same effects repeatedly.

The illustrations below show the addition of a sharpening layer and layer mask to concentrate the effect to the horizon to alleviate the aerial haze in downtown San Francisco. After the sharpening we created a Color Fill layer set to a Color blend mode and opacity of 33%. The exact opacity will vary, since the amount of color needed to kill a colorcast will vary. The main idea to grasp is to select a color that is the opposite color of the haze.

Building a haze-cutting layer. Creating a sharpening layer at the top of the layer stack. Creating the layer mask for the hazecutting layer. Adding a Color Fill layer.

Creating a Clipping Mask

Once you’ve added the Color Fill layer, you’ll see that the color goes over the entire image. We want to localize the cooling color just to the areas where we painted in the layer mask. To accomplish this, we’ll create a Clipping Mask so the Color Fill layer will be applied only in the areas where we painted in white on the sharpening layer’s mask. In this way, the one layer mask controls both layers’ local opacities. It’s a useful two-for-one deal and allows for adding or subtracting both effects at the same time. You’ll note, however, that the Color Fill layer retains its own discrete layer mask in the event you need to edit the local opacity of just the Color Fill layer.

The illustrations below show selecting the Layer > Create Clipping Mask command as well as the resulting layer stack with the Color Fill layer clipped to the Haze Cutting layer mask.

Creating a clipping mask. The resulting layer stack with the Color Fill layer clipped to the Haze Cutting layer mask.

The final result both clears the warm smog haze from the skyline and pops out the detail of the distant buildings. The illustration below shows the results of applying the haze-cutting effect.