The elusive alpha channel remains one of the most misunderstood yet powerful tools in Photoshop. Alpha channels are collections of luminance data that control the transparency of an image, and they inform just about every aspect of Photoshop. Selections, layer boundaries, the Quick Mask mode, layer masks, knockouts, and the Channels palette all rely on alpha channels. In Photoshop CS3 Channels and Masks, award-winning author and Photoshop expert Deke McClelland taps the vast capabilities of popular tools like layer masks, luminance blending, and paths. He also takes on many little known but very useful features, including Calculations, blue-screen masking, high dynamic range, and displacement masks. Plus, Deke teaches how to select and composite highlights, shadows, clouds, fabric, feathers, glass, flames, lights, eyes, and all kinds of hair. Exercise files accompany the tutorials