Alpha channels are collections of luminance data that control the transparency of images, and they influence just about everything in Photoshop. Learning how to work with Channels and Alpha channels; which are also known as Masks, is a great way to add power to your Photoshop toolbox.

Your trainer for this library is Deke McClelland. Deke McClelland is a well-known expert and lecturer on Adobe Photoshop, Illustrator, InDesign, and the broader realm of computer graphics and design. To date, he has written 85 books that have been translated into 24 languages, with more than 4 million copies in print. This library is divided into 10 lessons and runs 12.5 hours. This is the first part in the Photoshop CS3 Channels And Masks series. Part two is called Photoshop CS3 Channels And Masks: Advanced Techniques and is also available from Lynda.com

Lesson 0, "Introduction" shows you how to set up a few key preferences, short cuts, and how to load color settings into Photoshop. You will also learn how to synchronize color settings across CS3.

Lesson 1, "How Channels Work" starts off with the basic premise that "Channels are everything." Since Photoshop sees everything in three channels of grayscale, it is important that you learn how to use these channels. Coming to grips with masking is the best way to boost the quality of your work in Photoshop. You will learn the Channels palette, RGB Color, Lab color, and single color grayscale. You will also learn of duotones, tritons, and quadtones, as well as about the 16-bit advantage.

Lesson 2, "How Masks Work" talks about the non-color bearing brethren of the color channel; also known as the alpha channel. You will see how alpha channels work, how they accommodate masks and what masking is all about.

Lesson 3, "Selection Essentials" shows that, while on the surface, selections are relatively simple; there are a lot of things that most people don't know about selections, or don't take the time to learn about. These include floating selections, how anti-alias works, and partially selecting pixels.

Lesson 4, "The Automated Selection Tools" is about the big three automated selection tools; the Magic Wand, the Quick Selection Tool, and the Magnetic Lasso. Now that you know how to select, you will learn how to use these tools, and how they work with the refine edge command. You will also learn how these tools perceive colors and edges; which goes to the heart of how Photoshop sees an image.

Lesson 5, "Combining and Transforming Selections" shows you that selection outlines are full fledged objects that can be moved, scaled, rotated, and otherwise modified. In this lesson you will learn how to combine and transform selections and make them do your bidding.

Lesson 6, "Color Range and Quick Mask" describes that the best selection tool in all of Photoshop is not even a tool, it is a command called Color Range. It is dynamic and recognizes gradual organic edges. It also serves as an intro to the larger world of Masks. You will also get an introduction to the Quick Mask Mode.