Sony DSC-W80/B Sony® Guide to Digital Photography (Spring 2007) - Page 12

Shooting the digital way CAMERA SYSTEMS Optional conversion lenses and filters Attach optional conversion lenses for additional focal lengths; attach filters for stunning special effects. Selected Sony Cyber-shot® cameras enable you to exceed the zoom range of the built-in lens, thanks to optional conversion lenses. Or unleash your creativity with optional filters. The DSC-W55 accepts the optional VAD-WB lens adaptor, while the DSC-W200 accepts the optional VAD-WD lens adaptor. These adaptors enable you to mount optional conversion lenses and special effects filters. The DSC-H7 and H9 feature a 74mm lens thread that accepts optional conversion lenses and filters directly. Use the polarizing filter of the Sony VF-30CPKS to control reflections off water or glass. (Sample photos for illustration purposes.) The neutral density filter of the Sony VF-30NK helps control bright outdoor scenes, for images of more subtlety and beauty. (Sample photos for illustration purposes.) The image sensor After the lens, light passes from the subject to an integrated circuit chip called the image sensor. The sensor occupies the spot where the film would be on a conventional camera. Where film converts the incoming light to chemical changes in the emulsion, the image sensor converts light first into an electric charge, then into analog voltage. Some image sensors also take the next step, converting the analog voltage into digital bits. Conversion lens adaptors extend the capabilities of many Sony cameras. So you can shoot wider angles and longer telephotos as well as take advantage of polarizing, neutral density, star, and soft filters. The star filter of the Sony VF-30SC lends a dramatic touch to picture highlights. (Sample photos for illustration purposes.) The soft filter of the Sony VF-30SC adds the right touch of diffusion for romantic portraits, emotional subjects and atmospheric landscapes. (Sample photos for illustration purposes.) Pixels and megapixels While a film image is composed of discrete chemical grains of irregular size and shape, a digital image is composed of discrete squares of color called pixels. The pixels that form a digital image begin as discrete, light-sensitive areas on the surface of the image sensor. One million pixels is called a "megapixel." And it appears that everyone understands that more megapixels are better. Here's why. The more megapixels you have, the bigger prints you can make at a given image quality. More megapixels create images ready to use in printed flyers and brochures. And higher megapixel counts enable you to crop the image or use digital zoom - without sacrificing too much picture detail. 20 CAMERA SYSTEMS VGA 3 MP 5 MP 8 MP 10 MP 12 MP 4000 640 2048 2592 3264 3648 480 1536 1944 200 200 200 dpi dpi dpi 2448 200 dpi 2736 200 dpi 3000 200 dpi 3.2" 10.2" 13.0" 16.3" 18.2" 2.4" 7.7" 9.7" 12.2" 13.7" 20.0" 15.0" More megapixels mean finer detail and larger print sizes. Shown here: print sizes for high quality at 200 dots per inch. (Sample photo for illustration purposes.) PRINT SIZE 3 x 4 Inches 4 x 6 Inches 5 x 7 Inches 8 x 10 Inches 11 x 14 Inches 16 x 20 Inches 20 x 30 Inches 12 MP 1000 750 600 400 286 200 150 10 MP 912 684 547 365 261 182 137 PRINT DPI 8 MP 5 MP 816 648 612 486 490 389 326 259 233 185 163 130 122 97 3 MP 512 384 307 205 146 102 77 VGA 160 120 96 64 46 32 24 KEY: Ideal picture quality Good picture quality Not recommended Anything above 300 dpi is photo quality, shown in green. High quality printing, from 200 to 300 dpi is shown in orange. Printing below 200 dpi will not yield high quality. Color The pixels of the typical image sensor are sensitive to all colors of light. Without outside help, they can only see images in "black and white." To capture color, they require the help of a color filter array. This is a mosaic of microscopic filters that permit light of only one color - Red, Green or Blue - onto each pixel. Red, Green and Blue are the "additive primary" colors. This means that different proportions of Red, Green and Blue can be added to reproduce any visible hue. The Bayer color filter array permits light of only one color to fall on each pixel. RED MAGENTA BLUE YELLOW CYAN GREEN Different proportions of Red, Green and Blue can be added to reproduce any visible hue. 21