How Do Digital Cameras Work

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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.

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.

During the conversion, the light is filtered into the three primary colors, which are combinable to create a full spectrum light. Better quality digital cameras use three separate sensors to do this. Each sensor contains a filter of a different color, allowing it to read just the light that matches.

Aperture and shutter speed are the mechanisms used to control the amount of light that reaches the sensor. In most digital cameras the aperture setting is automatic, but some cameras also allow manual control. Professional photographers and enthusiasts prefer this option. The shutter, on the other hand, is set electronically.

There are four kinds of lenses used by digital cameras: optical-zoom lenses with automatic focus; fixed-focus, fixed-zoom lenses; digital-zoom lenses; and replaceable lens systems. Optical zoom lenses have both telephoto and wide options, while the fixed focus and fixed zoom lenses are used in the ordinary, inexpensive cameras that infrequent users own. The digital zoom lens creates the illusion of a zoom effect by culling pixels from the central part of the image and enlarging them to fill the frame. This, however, often results in a grainy or fuzzy image at the extreme limits of the camera's capabilities.

An LCD screen is standard on most digital cameras today, and they help in previewing images and also checking them out after taking a shot. Many screens are rather small, because there is only so much space on a camera for them. It is always best to transfer the images to a computer for viewing. In terms of image quality in general, the higher resolution the camera, 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.

Early digital cameras stored images on memory resources built into the camera. Images were then transferred to computers with the help of cables. Most modern digital camera makers utilize reusable and removable storage devices. These devices include SmartMedia cards, CompactFlash cards and other memory sticks. Other, less common removable storage devices include hard disks or microdrives, and writeable CDs or DVDs. These options have considerably enhanced the volume of visual data that can be stored as well as the overall flexibility of the modern digital camera.