Adjusting Images

A day will come when a camera will be introduced that can compensate for every possible thing that could go wrong in the fraction of a second it takes to snap a photo. Like the sun going behind the clouds at the just the wrong moment. Like the flash not going off for some reason. Like the bright yellow taxi that just drove by. Like the lights that just went out.

Until that day comes, photos will always need some kind of adjustments made to them so that they reproduce and print the way you want them to. Above that, sometimes you want to purposefully embellish photos, such as give them a specific color cast or engulf them in shadows.

Photoshop contains a wealth of tools and functions that can help you turn less-than-ideal photos into perfect ones.

Auto Controls

For quick fix-me-ups, Photoshop has three "auto" controls that can make adjustments to files: Auto Levels, Auto Contrast, and Auto Color. All three can be found in the Image, Adjustments submenu (see Figure 5.90). Depending on the photo, these controls can either be "okay" or useless. At times, you just want a quick edit, and that's fine, but for most other tasks, you'll want to read on….

Figure 5.90. The Auto Levels, Auto Contrast, and Auto Color commands in the Image, Adjustments submenu.

Levels

A step above the auto controls is the Levels command. Press Command+L (Ctrl+L) to bring up the Levels dialog box. Notice that you are presented with a histogram that shows you the highlight, shadow, and midtone areas of your image (see Figure 5.91). Drag the little triangle sliders to make adjustments.

Figure 5.91. The Levels dialog box.

You can adjust the black-and-white points of your image by selecting the black eyedropper tool in the dialog box and then clicking on the darkest area of your photo. Repeat again with the white eyedropper, clicking on the lightest point in your image. The histogram then updates as Photoshop makes the adjustments.

Did you Know?

I often use levels to "tint back," or lighten, images. Drag the black Output Level triangle (lower left) toward the right until you get what you need.

What's great about the Levels dialog box is that you can apply these changes to the entire image overall, or you can make adjustments to specific color channels by choosing one from the pop-up menu (see Figure 5.92). When you're happy with the adjustments you've made, click OK.

Figure 5.92. Choosing to edit the levels of the magenta channel only.

Curves

Although the Levels feature is easy to use and pretty much straightforward, it's limited to applying linear adjustments only. For even more control over the tonal range and values of your images, choose Image, Adjustments, Curves. Here you also have the eyedroppers to choose black and white points, but you have more precision when it comes to making tonal adjustments.

The grid in the center is your imagethe region at the upper right is where the highlights are, and the region at the lower left is where your shadows live. Midtones are smack in the middle (see Figure 5.93). You can click in the grid to add a point and drag it to adjust the curve. The benefit here is that you can open up the shadows, but you can also add more points and adjust the curve to keep the highlights from getting blown out (see Figure 5.94).

Figure 5.93. The different areas of the Curves grid.

Figure 5.94. Adjusting a curve.

Did you Know?

As you drag in your document, a circle appears on your curve indicating where that area falls on the curve. You'll see that as you click on the lighter areas of your image, the circle appears closer to the top right of the grid, whereas darker areas fall lower and to the left (see Figure 5.95).

Figure 5.95. The circle indicates where on the curve your chosen pixel is.

Just as with levels, you can apply curves to the entire image as a whole or to individual channels. When you've made your adjustments, you can click OK.

Shadow/Highlight

The Shadow/Highlight command automatically adjusts both the shadows and the highlights of a picture while using "smart" intelligence to ensure that the image doesn't lose any detail. In my humble opinion, this is probably the most valuable of all the adjustments in Photoshop.

By the Way

The Shadow/Highlight command now works on RGB, CMYK, and grayscale images.

To use this command, choose Image, Adjustments, Shadow/Highlight. Use the Shadows and Highlights sliders to make adjustments as necessary, and then click OK (see Figure 5.96).

Figure 5.96. Adjusting the Shadow/Highlight sliders.

Adjustment Layers

All the adjustments we've spoken about until now are called destructive adjustments because after these adjustments are applied, the actual pixels in the file are changed and there's no way to go back to the original version of the file.

Although sometimes you know that what you're doing is final (or you have the original backed up, if you need it), there are plenty of times when you are required to make multiple adjustments (for example, each time you go back to visit the clients, they change their mindalthough I'm sure that never happens to you).

So Adobe created something called an adjustment layer that enables you to keep certain adjustments "live" and editableeven long after you've saved and closed the file. This is accomplished by adding the adjustment itself as a special kind of layer. To add an adjustment layer for Levels, for instance, click on the Adjustment Layer button at the bottom of the Layers palette and choose Levels (see Figure 5.97). You'll see the normal Levels dialog box, as you've seen earlier, but when you click OK, you'll notice that a new layer has been added to your file. Any layer that falls below this adjustment layer will be affected by it (see Figure 5.98).

Figure 5.97. Applying an adjustment layer.

Figure 5.98. The applied adjustment layer, as it appears in the Layers palette.

Did you Know?

Adjustment layers are great when you want to make adjustments to only certain layers in your file. Any layers that appear above the adjustment layer aren't affected.

At any time, you can double-click on an adjustment layer to edit it or make changes to it (double-click on the adjustment thumbnail, not the name of the layer). Of course, you can also drag it to the Trash icon in the Layers palette if you want to get rid of it altogether.

Did you Know?

You can also have adjustment layers affect only a portion of a file by first making a selection and then adding the adjustment layer. In doing so, you create an adjustment layer with a layer mask.

Match Color

It always ends up that the lighting and color are good in some photos from a photo shoot, but the person's expression and face are better in another. Using the Match Color feature, you can pull the color from one image and apply it to another one.

First, open both imagesthe one you want to change and the one that has the perfect color, which we'll call the source image (that's where the color data will be coming from). From the document that has the bad color, choose Image, Adjustments, Match Color to open the Match Color dialog box. The first step is to look at the Image Statistics area and, from the Source pop-up menu, choose the source file (see Figure 5.99). Now that you can see the new color applied, you can tweak the settings using the sliders in the Image Options section of the dialog box. When you're done, click OK.

Figure 5.99. Choosing the source file in the Match Color dialog box.

Dodge and Burn Tools

If you've ever spent time in a traditional darkroom, you know that dodging is underexposing film, making it lighter, whereas burning film is overexposing it, making the image darker. Photoshop has both Dodge and Burn tools that let you "paint on" these kinds of effects. Simply choose the Dodge or Burn tool (see Figure 5.100), choose a brush size, and go to town.

Figure 5.100. Choosing the Burn tool from the toolbox.

Did you Know?

While using the Burn tool, you can hold down the Option (Alt) key to temporarily access the Dodge tool. The same applies in the reverse.