Seeing in black and white
Black and white conversions are radical transformations of images. They’re about reestablishing the tonal foundations of an image. That’s quite different than dodging and burning, or lightening and darkening locally, which is a matter of accentuating existing tonal relationships.

Conversion methods
There are almost a dozen ways to convert an image from color to black and white; and you can probably find at least one expert to support each way as the best conversion method. The bottom line is that most conversion methods work reasonably well. The method that works best for you depends on your particular workflow and the tools that you’re comfortable with. The following method isn’t necessarily the best and it isn’t the fastest—it generates a larger file—but it offers you the most control and flexibility.

Creating layers from channels offers you more control than any other conversion method. It also offers you the flexibility of being able to change any aspect of the conversion at any time in the future. Here’s how you do it: copy the individual channels of a color image,and then paste them into the same document as the original color image.Next, rename the layers accordingly. Then, reduce the opacity of the layers to achieve the result that you want. If you want a neutral image and don’t want the color of the Background layer to show through, keep the opacity of the layer directly above the color Background layer at 100%.
Since you will be going back and forth between the Channels palette and the Layers palette during this exercise, it helps to separate these two palettes by dragging them apart, and putting them side by side, as shown here.

Download pdf Adobe Photoshop CS Black and White Conversion