If you use a digital camera, it can help to have a little deeper understanding how these modern wonders work. Briefly, digital cameras have a series of lenses that focus light onto a sensor instead of film. The sensor electronically records the image, and transfers it to the "brains" of the camera. Here it is organized and then converted into binary data, so it can be stored in memory or on removable memory units for later reading by a computer or printer.
The most common digital camera sensor is a charge-coupled device, or CCD, but some models use a complementary metal oxide semiconductor (CMOS). In either case, light beams are converted to electrical charges, which are then transferred to the core electronic section, and eventually onto the storage media.
As part of this process the sensors filter the light into the three primary colors, which can be combined to create the full spectrum. The more expensive (and higher quality) cameras use three separate sensors to accomplish this task. Each sensor is fitted with a filter of a different color, making it read only the light that matches that color.
The amount of light reaching the sensor is also controlled carefully. Cameras do this in two ways: aperture size, and shutter speed. Most of today's cameras have automated aperture settings, although some models allow manual control, which enthusiasts and professionals prefer. Shutter speed is generally set electronically.
Lenses for digital cameras come in four varieties: digital-zoom lenses; fixed-zoom lenses; replaceable lens systems; and fixed-focus. Fixed lenses, both zoom and fixed focus, tend to be found in the cheaper cameras. Optical zoom lenses can have both wide angle and telephoto options. Digital zoom lenses don't actually zoom a piece of glass, but rather take pixels from the central part of the image, and enlarge them. This appears to be a zoom, but if you look closely, you will notice that they are more grainy or fuzzy images than you get without invoking the zoom option.
Most digital cameras come with an LCD screen to preview images or to look at them after capture. Most LCD screens are rather small, because the size of the cameras overall is small, too. For better viewing, you must transfer the image to a computer. For quality of image, the biggest factor is the resolution, which is measured in megapixels. The higher the resolution, generally the better the image quality.
Resolution also plays a role in the quality and size of the printed photographs. A cell phone camera or other low quality camera with a one megapixel resolution will produce images that are really only good for emailing or web pages, not printing. With a 2-megapixel camera, the images are good for printing at 4x6 inch sizes or so, while a 4-megapixel camera can be detailed enough to produce good prints at 16x20 inch size. With prices falling continually, if you love photos and hope to make some enlargements, you are best to only consider cameras above 6-megapixels.
Several years ago, digital cameras stored images onto fixed memory locations inside the camera. Users needed a cable to hook up to a computer in order to transfer images. Today's cameras all use removable, reusable memory media, and are therefore much more flexible and convenient. Larger amounts of storage are easy to purchase, so one can also take higher resolution pictures without fear of running out of memory. Various systems for storage include SmartMedia cards, memory sticks, and CompactFlash cards. Other cameras use microdrives, like little hard drives, or DVDs. Whichever method your camera uses, the convenience and freedom that digital photography allows will turn you into a shutterbug in short order!
