Other Methods For Electronic Photography
The specialized field known as "image processing" is growing out of electronic photography. An electronic photograph may be taken using a still video camera, a video camera (using a single frame for the still image), or by digitizing a photographic image by using a scanner. After the photographic data has been stored, it can be manipulated by computer software in any number of ways. Parts of the photo can be erased, colors can be changed, composites can be made from several photographs, and contrast, sharpness, overall size, and size changes by cropping can be accomplished by tweaking the data. By the late 1980s, the advertising industry especially had experimented extensively with this new technology and produced startling images by combining photographic images in unlikely combinations. By the 1990s, scanners had improved greatly in resolution as well as dropping in price and were becoming standard accessories for the home computer.
Scanners and other image input devices have been made possible largely because of charge-coupled devices or CCDs. A CCD is an integrated circuit that produces an electrical charge that is unique to light striking a sensor element in the circuit. They are used in cameras (still and video), scanners, high definition televisions (HDTVs), and many other image-makers. Their speed and sensitivity has improved dramatically since they were first introduced in the 1970s, and they have made imaging devices affordable for desktop use.
Scanners are available in a wide range of models that use different techniques. Desktop versions scan flat photographs in either black and white or color (color uses three scans to capture the basic image in black and white and then add color in two scans), and scanners for 35-millimeter slides are also in desktop sizes and are often used for professional work.
Part of the attraction of electronic photography is the fact that images can be compressed as digital files and stored in a number of ways. Magnetic diskettes, rewritable CD-ROMS that use optical memory and recover images with laser readers, and cards and chips offer storage options depending on uses and cost. They also make the "electronic darkroom" possible for retouching and altering images; techniques for modifying photographs form the bridge between photographic images and computer-generated ones.
Technologies that are affordable by the general public may still have some limitations in quality, especially in resolution (clearness of the image), shading and color ranges, and saturation. Systems used to make commercials and magazine ads, however, produce high-quality images.
Larish, John J. Electronic Photography. Blue Ridge Summit, PA: TAB Professional and Reference Books, 2000.
Glumac, Nick. "Building a Fiber-optic Spectrograph." Sky & Telescope (February 1999): 134.
Shaefer, Bradley E. "Limiting Magnitudes for CCDs." Sky & Telescope (May 1998): 117.
Gillian S. Holmes
Science EncyclopediaScience & Philosophy: Philosophy of Mind - Early Ideas to Planck lengthElectronic Photography - The Digital Still Camera, Applications, Video Cameras, Other Methods For Electronic Photography