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LESSON
CO R R E C T I N G CO LO R B A L A N C E
DEEP INSIDE the most primitive recesses of our
minds—where thoughts such as “must eat to live” reside— we possess an implicit understanding of luminosity. Sunlight illuminates all things on this planet. Those things reflect highlights and cast shadows. These highlights and shadows permit our eyes to distinguish form, texture, and detail. We need variations in luminosity to see. By comparison, color is a subjective abstraction. After completing Lesson 2, you could probably provide a concise one-sentence description of the word midtones. But could you so elegantly describe orange or purple, words that you’ve bandied about since you were a tot? And who’s to say what you call orange, I might not call scarlet, amber, or even red?
A strawberry is a strawberry
In day-to-day life, our tenuous understanding of color is generally sufficient. After all, color is mostly window dressing. We don’t use it to identify; we use it to clarify. As illustrated in Figure 3-1, you recognize a strawberry by its luminosity; you know whether it’s ripe by its color. Millions of people suffer some degree of color blindness and get along with only minor inconveniences—picking unripe strawberries, for example. But if Figure 3-2 is any indication, without variations in luminosity, you’d have a hard time identifying anything.
Red makes it ripe
Figure 3-1.
Figure 3-2.
By itself, color conveys little more than a vague imprint of an object 63
ABOUT THIS LESSON This lesson introduces you to Photoshop’s most capable color adjustment commands, Variations, Hue/Saturation, and Gradient Map. We’ll also explore such concepts as white balance and color temperature when we look at one of Photoshop CS’s most powerful capabilities, integrated support for so-called Camera Raw. You’ll learn how to:
Project Files Before beginning the exercises, make sure that you’ve installed the lesson files from the CD, as explained in Step 5 on page xv of the Preface. This should result in a folder called Lesson Files-PScs 1on1 on your desktop. We’ll be working with the files inside the Lesson 03 subfolder.
• Neutralize an image with a widespread color imbalance . . . . . . . . . . . . . . . . . . page 66 • Increase the saturation of a drab photo . . . . . . page 72 • Colorize a black-and-white photograph . . . . . page 75 • Import and edit a high-color photograph shot with a digital camera . . . . . . . . . . . . . page 81
Video Lesson 3: Color Balance and Camera Raw The most obvious command for adjusting color balance is Image Adjustments Color Balance. But as noted in the preceding lesson, Photoshop’s most obvious solutions are rarely its best. Better are commands that don’t have the word color or balance in their names at all, such as Variations and Hue/Saturation. To acquaint yourself with these commands, watch the third video lesson on the CD. To view the video, insert the CD, click Start Training, and then select 3, Color Balance & Camera Raw from the Lessons list on the right side of the screen. This 9-minute 36-second movie ends with a look at Photoshop’s revamped capability to open and adjust raw files from a digital camera. Shortcuts include the following: Command or operation
Windows shortcut
Color Balance
Ctrl+B
-B
Variations
Ctrl+Alt+A*
-Option-A*
Hue/Saturation
Ctrl+U
-U
Advance to next option
Tab
Tab
Nudge numerical value
or
or
Nudge values in 10× increments
Shift+ or
Macintosh shortcut
Shift- or
* Works only if you loaded the Deke Keys keyboard shortcuts (as directed in Step 12 on page xvii of the Preface).
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Lesson 3: Correcting Color Balance
Once we enter Photoshop, however, color changes from window dressing to prime commodity. To broker in that commodity, you must know how to take it apart, define the pieces, and reassemble it. Unless you aspire to become a color scientist—such folks do exist—this may seem like an arcane if not downright impossible task. But by the end of this lesson, terms such as hue and saturation will seem so familiar, you may be inclined never to utter the words “orange” or “purple” again.
What Are Hue and Saturation? Color is too complex to define with a single set of names or numerical values. After all, if I describe a color as orange, you don’t know if it’s yellowish or reddish, vivid or drab. So Photoshop subdivides color into two properties, hue and saturation:
Figure 3-3.
• Sometimes called the tint, the hue is the core color—red, yellow, green, and so on. When you see a rainbow, you’re looking at pure, unmitigated hue. • Known variously as chroma and purity, saturation measures the intensity of a color. By way of example, compare Figure 3-3, which shows a sampling of hues at their highest possible saturation values, to Figure 3-4, which shows the same hues at reduced saturations. The stark contrast between Figures 3-3 and 3-4 may lead you to conclude that garish saturation values are better. But while this may be true for fruit and candy, most of the real world is painted in more muted hues, including many of the colors we know by name. Pink is a light, low-saturation variation of red; brown encompasses a range of dark, low-saturation reds and oranges. Figure 3-5 shows a collection of browns at normal and elevated saturation levels. Which would you prefer to eat: the yummy low-saturation morsel on the left or the vivid science experiment on the right?
Figure 3-4.
Continuing the trend laid out in the preceding lesson, Photoshop provides several commands that give you selective control over all aspects of color, including hue, saturation, and more specialized attributes. Armed with these commands, you have all the tools you need to get the color balance just right. Low-saturation cookie goodness
Unfit for human consumption
Figure 3-5.
Adobe Photoshop CS One-on-One
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Fixing a Color Cast One of the most common color problems associated with digital images and photographs in general is color cast, a malady in which one color pervades an image to an unrealistic or undesirable degree. For example, an old photograph that has yellowed over the years has a yellow cast. A snapshot captured outdoors using the wrong light setting may suffer a blue cast. Naturally, Photoshop supplies a solution, and a simple one at that. Designed to remove a prevailing color cast and restore the natural hue and saturation balance to an image, Image Adjustments Variations may be Photoshop’s most straightforward color adjustment command. Rather than previewing your corrections in the main image window, as other commands do, Variations presents you with a collection of thumbnail previews. Your job is to click the thumbnail that looks better than the one labeled Current Pick. You can click as many thumbnails as you like and in any order. The following exercise walks you through a typical use for the Variations command: 1. Open an image. Open the file Color science.jpg in-
cluded in the Lesson 03 folder inside Lesson FilesPScs 1on1. Captured without a flash under colored lights on the set of Total Training for Photoshop Elements— where I played one of those kooky chemists whose specialty is dry ice—this image suffers from what I like to call “A Nutty Preponderance of Red” (see Figure 3-6). PEARL OF
WISDOM
The problems with the image in Figure 3-6 bear some resemblance to those that we corrected with the Levels command in Lesson 2 (see “Adjusting Brightness Levels” on page 44). And in truth, you can fix much of what ails this photograph with Levels. But because the main offender here is color cast, Variations is the easier solution. Unlike Levels or any of the other commands from Lesson 2, Variations can recruit information from one channel and bring it into another, an enormous advantage when correcting color balance.
Figure 3-6.
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Lesson 3: Correcting Color Balance
2. Choose the Variations command. Choose Image
Adjustments Variations, as shown in Figure 3-7, to display the gargantuan Variations dialog box. By default, Photoshop does not include a shortcut for Variations. Under Windows, you can access the command by pressing Alt and typing “Ian.” On the Mac, you have to assign a shortcut using Edit Keyboard Shortcuts. Or you can use my shortcuts. If you loaded the custom shortcuts that I recommend in the Preface (Step 12, page xvii), the shortcut is Ctrl+Alt+A ( -Option-A on the Mac).
3. Click the Original thumbnail. Variations is one of the
few color adjustment commands that automatically remembers the last adjustment you applied. This is helpful when revisiting the dialog box if a correction doesn’t quite turn out the way you had hoped. But for this exercise, you’ll want to clear the old correction (if indeed there was one) and start from scratch. Clicking the top-left thumbnail, the one labeled Original, does exactly that (see Figure 3-8).
Figure 3-7.
4. Select the Midtones option. Like Levels, the Variations
command lets you apply your changes to the highlights, midtones, or shadows in an image. You do so by selecting one of the first three radio buttons near the top of the dialog box. When correcting a color cast, however, you almost always want the default setting, Midtones. (Shadows is sometimes useful, Highlights almost never.) Make sure Midtones is selected.
5. Turn off Show Clipping. As you adjust hue and satu-
ration, some colors may become unprintable. That is, they move outside the range reproducible by the process color inks: cyan, magenta, yellow, and black (CMYK). These colors are clipped to the closest neighboring color. When the Show Clipping check box is on, as by default, Photoshop tries to warn you about these clipped colors by inverting them. The problem is, the warning isn’t particularly accurate and it blocks what is already a small view of your image. For my part, I always turn Show Clipping off.
Figure 3-8.
Adobe Photoshop CS One-on-One
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