Rangefinder Magazine
February 2006

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Photoshop CS2 How² Michelle Perkins
Updates for Image Enhancements

1 The Spot Healing Brush offers a quick way to clean up isolated blemishes (left). When you click on the area to be concealed, a dark spot appears (center). This disappears when you release the mouse, and the area Photoshop sampled is blended in over the blemish (right)

2 The Red Eye tool offers a one-click solution to a common problem—and the results are usually very good

3 The Lens Correction dialog box provides a full-screen preview of your image with slider controls in a panel to the right.

4 and pin-cushioning, and distortion caused by the position of the camera relative to the subject, as seen here. Shot from below (left) the window narrows toward the top of the image (called keystoning). The Lens Correction filter made it easy to precisely line up the verticals for a truer, more accurate rendition (right).

5 This low-light image was taken under colored stage lights with an ISO setting of 400. The result is a lot of noise—colorful noise (left). Using the Reduce Noise filter improves the situation, although it’s not a perfect solution.

6 In the basic mode, you can adjust the Amount and Radius sliders and select the type of blur that needs to be removed.

7 In the advanced mode, you can also control the application of the sharpening to the highlights and shadows of your image.

8 With an image that needs light sharpening, the basic setting produces fairly prominent halos. Because there is no Threshold setting, as in the Unsharp Mask filter, the sharpening is also very visible on the skin. With the advanced setting, the problems are minimized, but the sharpening is less pronounced.

9 The Box Blur filter dialog box.

10 The Surface Blur filter dialog

11 The Box Blur and Surface Blur filters create distinctly different effects.

12 The Shape Blur dialog box.

13 The Shape Blur can create a number of different blur effects.

Two of the previous articles in this series have covered some topics that are certainly important—preferences and working with the Layers Palette—but they haven’t, perhaps, been all that glamorous. For most photographers, what gets our blood pumping is the thought of new tools for making our images look better—and, hopefully, for accomplishing that goal more quickly. Well, on that front, there’s good news in Photoshop CS2, which offers a number of handy improvements.

Spot Healing Brush

When the Healing Brush was added to Photoshop, photographers (for the most part) cheered. The Spot Healing Brush, which actually migrated into CS2 from Photoshop Elements, adds a new level of ease. While the Healing Brush functions much like a supercharged Clone Stamp tool (you sample an area and apply over another area), the Spot Healing Brush actually does a little bit more of the work for you. Rather than working from user-selected samples, the Spot Healing Brush automatically selects an area to sample, copying the color and texture from a surrounding area and blending it into the area where you click. How Photoshop determines what area to sample is set via the Options palette, where you can choose from Proximity Match (clones texture from a nearby area) or Create Texture (creates its own texture—good when working in areas with a lot of detail that won’t match up with the area you’re repairing). (figure 1)

Red-eye Tool

Another import from Photoshop Elements, this tool offers a quick solution to red-eye. Simply position the tool’s crosshairs over the center of the pupil and click. If the applied color extends too far (encroaching on the iris), reduce the Pupil Size setting in the Options palette. If the effect is too dark or removes too much detail, reduce the Darken Amount setting. (figure 2)

Lens Correction

The Lens Correction filter, new in CS2, provides access to controls previously available only in the Camera Raw dialog box, and supplements these with some additional options. (figures 3 and 4)

When you activate the filter, a full-screen dialog box appears with a large preview of your image. Superimposed over the image is a grid, which is helpful as a reference for squaring up your image. To change the size of the grid, simply adjust the Size box at the bottom of the window. In the pane to the right, you’ll find a series of sliders:

1. Remove Distortion—Compensates for barreling and pin-cushioning effects, which cause lines near the edge of the photo to bend out (barreling—common with wide-angle lenses) or in (pincushioning—common with telephoto lenses).

2. Chromatic Aberration—Lets you adjust for the slight prismatic effect of some lenses that produces halos of color around edges that should be sharp.

3. Vignette—Allows you to compensate for the darkened edges that sometimes appear when using a wide-angle lens at a wide aperture or catadioptric (mirror) lenses, (or you can use this slider to add a vignette for creative effect).

4. Transform—Lets you scale the vertical and horizontal perspective of your image to compensate for the distortion that occurs when the camera’s lens is not square with the subject.

Reduce Noise

The new Reduce Noise filter takes some of the hassle out of noise reduction by allowing you to remove the overall noise or, in the advanced mode, to remove noise by channel— which typically produces superior results. (Note: After switching to the advanced mode, click on the Overall tab, and set the Strength and Reduce Color Noise settings to zero. Otherwise, the information shown in the channels panel will be affected by the settings indicated by these sliders.) You can also reduce color noise and JPEG artifacts using this same filter. (figure 5)

Smart Sharpen

For many versions of Photoshop, the Unsharp Mask filter has been the tool of choice for sharpening images; the other available tools just didn’t come close. In Photoshop CS2, however, a new tool has been added that just might give Unsharp Mask a run for the money: Smart Sharpen (Filter > Sharpen > Smart Sharpen). There are two modes available, basic and advanced.

In basic mode, you’ll see two sliders. These control the Amount of sharpening (how much the contrast is increased on the edges) and the Radius (how wide an area will be affected by the contrast boost). Below them is a Remove menu. From this you can select Gaussian Blur, which will produce about the same effect as Unsharp Mask. The Lens Blur setting produces less visible halos than the Gaussian Blur setting. The Motion Blur setting lets you specify an angle setting to help remove blur that occurs due to camera motion. (figures 6 and 8)

The More Accurate checkbox causes Photoshop to perform the sharpening in two passes, which can produce a sharper image but also tends to yield more visible halos.

In advanced mode, the Sharpen panel offers the same settings as in basic mode. In addition, however, two tabs are added to control the application of these settings to the image’s highlights and shadows. Reducing the Fade Amount setting mutes the sharpening effect overall— just like reducing the opacity of a layer. The Tonal Width setting defines what will be considered a shadow or highlight and, therefore, the areas where the sharpening will be applied. Once you’ve set the Fade Amount and Tonal Width to produce an effect you like, you can use the Radius setting to help blend the transition between sharpened and faded areas. (figures 7 and 8)

Blur Filters

Three new blur filters have been added in Photoshop CS2.

Box Blur. The Box Blur filter works like Gaussian Blur and provides similar results—but significantly faster, which can be a nice advantage when working with large files. (figures 9 and 11)

Surface Blur. The Surface Blur filter reduces image detail while maintaining sharp edges, so your photographic image can end up looking more like an illustration. (figures 10 and 11)

Shape Blur. The Shape Blur blurs your image based on the shape you specify. For the maximum variety of shapes to pick from, click on the dropdown menu at the top right of the shapes field in the Shape Blur dialog box and select All. (figures 12 and 13)

All in all, the changes to CS2’s image-enhancing features are not extremely dramatic. The new tools do, however, offer some nice enhancements that can make your time spent in front of the computer a bit more fun and efficient.