| Digital cameras have now fully completed their coup | | | | fixed zoom lenses are used in the ordinary, |
| of the camera industry. If you recently got one | | | | inexpensive cameras that infrequent users own. The |
| yourself, it can be useful to have a bit more | | | | digital zoom lens creates the illusion of a zoom effect |
| understanding of how they work. Simply put, digital | | | | by culling pixels from the central part of the image and |
| cameras contain a lens or series of lenses that allow | | | | enlarging them to fill the frame. This, however, often |
| light passing through them to focus on a sensor, rather | | | | results in a grainy or fuzzy image at the extreme limits |
| than traditional film. The sensor then transfers the | | | | of the camera's capabilities. |
| image data to the core electronics of the camera, | | | | An LCD screen is included on most digital cameras to |
| where it is organized and converted into binary forms | | | | view the image. These screens are usually rather |
| of data. Thus it can more easily be stored onto | | | | small, being constrained to the size of the camera. |
| reusable memory units for later viewing by a | | | | Thus the image needs to be transferred to a |
| computer. | | | | computer for better viewing or printing. The overall |
| When it comes to the sensor, most digital cameras | | | | quality of the image depends primarily upon the |
| use a charge-coupled device (CCD), while other | | | | resolution of a digital camera. The higher the resolution, |
| cameras use a complementary metal oxide | | | | measured in megapixels, the better the image quality. |
| semiconductor (CMOS) instead. Both sensors convert | | | | For printing photos, resolution of the original image is |
| light into electrical charges, which are then read by the | | | | also key. A low quality camera such as those found in |
| electronics in the camera and transferred to the | | | | many cell phones will create images that are really |
| relevant storage media. | | | | only useful for emailing or for web pages. A |
| During the conversion, the light is filtered into the three | | | | 2-megapixel camera produces images that can be |
| primary colors, which are combinable to create a full | | | | blown up to about 4x6 inches. Four megapixels will |
| spectrum light. Better quality digital cameras use three | | | | create nice 16x20 inch images, but with falling prices on |
| separate sensors to do this. Each sensor contains a | | | | most digital cameras, if you enjoy photography and |
| filter of a different color, allowing it to read just the light | | | | enlarging photos, don't settle for less than six |
| that matches. | | | | megapixels. |
| The amount of light reaching the sensor is also | | | | Early digital cameras stored images on memory |
| controlled carefully. Cameras do this in two ways: | | | | resources built into the camera. Images were then |
| aperture size, and shutter speed. Most of today's | | | | transferred to computers with the help of cables. Most |
| cameras have automated aperture settings, although | | | | modern digital camera makers utilize reusable and |
| some models allow manual control, which enthusiasts | | | | removable storage devices. These devices include |
| and professionals prefer. Shutter speed is generally set | | | | SmartMedia cards, CompactFlash cards and other |
| electronically. | | | | memory sticks. Other, less common removable |
| There are four kinds of lenses used by digital cameras: | | | | storage devices include hard disks or microdrives, and |
| optical-zoom lenses with automatic focus; fixed-focus, | | | | writeable CDs or DVDs. These options have |
| fixed-zoom lenses; digital-zoom lenses; and replaceable | | | | considerably enhanced the volume of visual data that |
| lens systems. Optical zoom lenses have both | | | | can be stored as well as the overall flexibility of the |
| telephoto and wide options, while the fixed focus and | | | | modern digital camera. |