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.
Most digital cameras' sensors are charge-coupled devices, or CCDs, although some cameras instead have a complementary metal oxide semiconductor, or CMOS. Either way, light is converted into electrical charges, which are transferred to the brain, and finally 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.
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.
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!
About the Author
Wilfred Ursley writes for a variety of popular Internet magazines, with tips and resources on digital cameras and personal health care themes.Visit our digital cameras article directory for a completely unique version of this article.