Real World Digital Photography, 2nd edition

Converting Color to Black and White

There are several methods you can use to turn a color original into a grayscale image in Photoshop. Some give you no control over how the conversion is made, while others let you brew a custom grayscale mix that gives you exactly the black and white look you want:

• Desaturate. This is probably the least useful of all the conversion methods. We'll mention it here just so you'll be aware of its shortcomings. As its name implies, the command desaturates all the colors in the image. When a color is desaturated by 100 percent, the result is a neutral gray value. The problem with this approach is that it doesn't always preserve the contrast between colors that you see in an RGB image. It also doesn't treat all brightness ...