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, masks, the Quick Mask mode, layer masks, knockouts, and masking with the Channels palette all rely on alpha channels. In
Photoshop CS2 Channels and Masks, award-winning author and Photoshop expert Deke McClelland teaches channels and masks comprehensively. From channel masks to blue screens, blend modes to displacement maps, Color Range to Calculations, this training leaves no pixel unturned. Deke also covers how to select and composite highlights, shadows, people, fabric, feathers, glass, flames, lighting, and wispy hair. Exercise files accompany the tutorials.