Adjusting Image Brightness (Levels Tool)

The Levels Adjustment tool provides an easy way to adjust the overall brightness of an image. And it does it without necessarily adjusting white or black point values. To make a brightness adjustment, open the Levels Adjustment dialog, and slide the center gray slider under the histogram.

Adjusting Image Contrast (Curves Tool)

The Curves tool provides a good way to adjust global image contrast. It allows for increased contrast in localized image tones (e.g., the midtones). Increased contrast in the midtones flattens the highlights and shadows resulting in a global increase in image contrast.

In the Curves dialog, place a point near the shadow end of the curve and drag it down to decrease contrast in the shadows. Then place a point near the highlight end of the curve and drag it up. Last, place a point near the midtone and adjust it for best global tone. This produces a typical S-Curve.

An inverse S-Curve produces a flattening of overall image contrast.

More on Curves in Chapter 2, Foundation. More on editing contrast in Chapter 5, Advanced Options.

Adjusting Shadows/Highlights (Curves Tool)

The Curves tool is also great for increasing the detail in highlights and shadows. It's best to perform this adjustment separate from using Curves to increase contrast, i.e., perform the separate adjustment tasks by creating two adjustment layers.

In the Curves dialog, first place a point at quarter tone, midtone, and three-quarter tone. This fixes the curve for most of the tonal image range and allows localized adjustment to the shadows only. Now place an additional point in the shadows and adjust it to bring out more detail.

Create a separate adjustment layer to add highlight details.

Options for using the Shadow/Highlight tool are in Chapter 5, Advanced Options (page 149).

Color Balance (Color Balance Tool)

The Color Balance tool is adequate for making large global image adjustments, so go ahead and use it for Color Balance adjustment. Open the Color Balance dialog and adjust the color levels. Move the sliders for each color channel to get the image to a fairly neutral color balance. The Color Balance Tool only provides for basic control of global color balance. More details on the Color Balance Tool in Chapter 2, Foundation.

But the Color Balance tool isn't the best tool for performing a color balance adjustment. Most people use the Curves tool for color balance. But start working with the Color Balance tool; it's good for understanding the basic color model used in digital images. More options for performing a color balance adjustment in Chapter 5, Advanced Options.

Edit Colors (Hue/Saturation Tool)

The Hue/Saturation tool provides some quick and easy steps to add some "snap" to your image. It also provides some precise control over editing individual image colors.

In the Hue/Saturation dialog, choose a color in the Edit list box to localize edits to a specific color range. (The default "Master" edits all color ranges.) The Hue option shifts the color range towards its adjacent colors, that is blue colors shift towards cyan or magenta. This is especially useful for color shifts localized in specific colors. You can also change the saturation of specific colors.

Change the Lightness option with care, as it affects global brightness and can turn pixels completely white or black (as in the Brightness/Contrast adjustment). More on the Hue/Saturation tool on in Chapter 2, Foundation (page 38).

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