Section 6.5. Color Balance Techniques

6.5. Color Balance Techniques

It's often hard to adjust color balance correctly because one part of the image is lit by a different color of light than another. I'm not talking about changing the color balance of a specific area but correcting all the areas of the image that were lit by a light source of a different color than the main light source. Examples of this would be colors reflected from walls, clothing, or tablecloths. Another common example would be a portrait taken by window light. The highlights might be lit by daylight and the shadows by the tungsten bulbs lighting the interior.

6.5.1. Using a Color Balance Adjustment Layer

The Color Balance adjustment layer is nondestructive, but not all that controllable when it comes to color balancing a specific brightness range in the image. You can choose whether the adjustments affect highlights, midtones, or shadows. You can also check a Preserve Luminosity box so the brightness range doesn't change as you make your adjustments.

In Figure 6-30, I've rebalanced the highlights so that the skin tones are warmer in the highlights, while the rest of the image has retained the original color balance. The end result is that the picture looks even more romantic.

Figure 6-30. On the right, the Highlights radio button was turned on and the Yellow slider increased by about 25 percent. Notice the warmer tones in the highlight areas and especially in the models' faces.

6.5.2. Using the Curves Adjustment Layer for Color Balance

I don't usually think of Curves as a way to adjust color balance, but you and I both should. It's too easy to forget that you can pick a single color channel from the drop-down menu on the Curves dialog and apply the curves to that color. This allows you to easily increase or decrease particular ranges of color. If your purpose in changing color balance is to set a different mood, changing small areas of color in the image can do it. It's also a good device for correcting colors in a limited spectrum in the image that might be caused by reflections or stray light. In Figure 6-31, the reds in the tree bark and the green of the vegetation and moss were both intensified in their own channels of the Curves layer.

Figure 6-31. The original image (left) and the same image after disproportionately changing color in two of the channels.

6.5.3. Levels Adjustment Layer

The Levels adjustment layer is also a good way to control color in a single channel. Again, you just choose the desired channel from the pop-up menu on the Levels dialog box. You can also control the range of that color a bit more accurately by moving the Highlight, Shadow, and Midtone sliders to limit the range of colors that will be affected in each channel. Figure 6-32 is an example of the sort of fantasy effects that can be created this way.

Figure 6-32. In the after image, each color channel was limited to about one-third of its normal brightness range. The adjustments were totally arbitrary.

6.5.4. The Auto Commands in Levels

If you followed my recommendations for adjusting the Levels adjustment layer in the Layers Workflow layers by adjusting each of the color channels individually, you have already come pretty close to attaining perfect color balance. If you haven't, I strongly suggest you go to the "Levels for Shadow, Highlight, and Overall Brightness" section of this chapter. There is a quicker way to do this, which is totally destructive: by using the Auto Color command in the Image Adjustments menu. Of course, nothing in Photoshop is quite what it appears to be and if you look carefully at the Levels dialog youll see a button labeled Auto. The default for this command is to do exactly what Auto Color does by clipping each channel Histogram at its minimum and maximum values. In fact, you can easily incorporate that adjustment into the Workflow Layers action so that this button is clicked as soon as the Levels layer is created. Now, when you're really in hurry, you'll have all your images auto color corrected. Figure 6-33 shows the result of clicking the Auto button using the default Enhance Per Channel options. To change the defaults, click the Options button.

Figure 6-33. A subtle but dynamic change in the color balance using the Temperature and Tint sliders in Camera Raw compared to using the Auto button in a Levels adjustment layer (right).

NOTE

Levels can be used to correct or subjectively change the overall (midtone) tint of the images channel by channel, just as you do when using the Color Balance command. Go back to the individual color channels and drag the midtone sliders. Be sure to have the preview box checked so that you can see the result.

6.5.5. When to Use Hue Instead of Color Balance

Since both Hue/Saturation and Color Balance adjustment layers change the overall color balance of the image, you may wonder when to use one instead of the other. Use Hue/Saturation when you want to:

• Color balance a CMYK image for fine-tuning output to offset printing devices (see Chapter 12).

• Create an effect that changes one set of basic colors to another. See Figure 6-34 for another example of this.

  Figure 6-34. An image as it came out of Camera Raw adjustment (left) and using the basic workflow layers in conjunction with the Hue/Saturation adjustment layer (right).

• Change the color balance or a range of colors and add or subtract saturation.

• Subdue the effect by lowering the opacity or fill of the adjustment layer.