How Do Digital Cameras Work?
Digital cameras have now fully completed their coup of the camera industry. If you recently got one yourself, it can be useful to have a bit more understanding of how they work. Simply put, digital cameras contain a lens or series of lenses that allow light passing through them to focus on a sensor, rather than traditional film. The sensor then transfers the image data to the core electronics of the camera, where it is organized and converted into binary forms of data. Thus it can more easily be stored onto reusable memory units for later viewing by a computer.
When it comes to the sensor, most digital cameras use a charge-coupled device (CCD), while other cameras use a complementary metal oxide semiconductor (CMOS) instead. Both sensors convert light into electrical charges, which are then read by the electronics in the camera and transferred to the relevant 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.
Digital cameras also control the amount of light that actually reaches the sensor. They do this through the aperture or hole size, and through the shutter speed. Most cameras have automatic aperture setting though some do allow for manual control, which is preferable for professional photographers and advanced amateurs. Shutter speed is 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.
An LCD screen is included on most digital cameras to view the image. These screens are usually rather small, being constrained to the size of the camera. Thus the image needs to be transferred to a computer for better viewing or printing. The overall quality of the image depends primarily upon the resolution of a digital camera. The higher the resolution, measured in megapixels, the better the image quality.
The potential size of the printed photographs is also decided by the camera's resolution. Because their resolution is relatively low, a 1-megapixel digital camera will produce images that are good for e-mailing or posting on the Web, and little else. The images taken by a 2-megapixel camera are suitable for 4x5 inch prints while good-looking 16x20 inch prints can be produced by a 4-megapixel camera. Better to get a 6 megapixel or higher model if you love working with photos.
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!
Article Source: http://articles411.com
Wilfred Ursley writes for a variety of popular Internet magazines, with information on consumer electronics and alternative health subjects.
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