WHAT IT IS ? A digital camera is a camera that, instead of capturing and storing pictures in photographic film like conventional cameras, it does digitally using an electronic device, or magnetic tape using an analog format like many video cameras.Modern compact digital cameras generally are multifunctional and contain some devices capable of recording sound and video as well as photographs. In this case, the device is also called digital camcorder. Now outsell digital cameras cameras with 35mm film.
HISTORY The concept of digitizing images on scanners and convert digital video signals to precede the concept of taking still frames digitized signals and an array of discrete sensing elements. Eugene F. Lally of the Jet Propulsion Laboratory published the first description of how to produce still photos in a digital domain using a photo sensor in mosaico.2 The purpose was to provide navigation information to astronauts during space missions onboard. The mosaic array periodically recorded still photos of star and planet locations during transit and when approaching a planet provided additional information for orbitaje distances and as a guide for landing. The concept design included elements that presaged the first digital camera.
Analogelectroniccameras Electronic analog cameras seem to have reached the market until 1986 with the Canon RC-701. Canon demonstrated this model at the 1984 Olympics, printing pictures in newspapers. Several factors delayed the widespread adoption of analog cameras: the cost poor image quality compared to the film, the lack of quality printers. Capturing and printing an image originally required access to equipment as a Frame grabber, which was beyond the reach of the average consumer. Video disks later had several reader devices available for viewing on a screen, but were never standardized impulse computers.
The arrival of true digital cameras The first real digital camera that recorded images on a computer file was probably the model Fuji DS-1P in 1988, he recorded on a card of 16 MB of internal memory and used a battery to keep data in memory. This camera was never put on sale in the United States. The first digital camera available in the market was the Dycam Model 1, in 1991, which was also sold under the name of photometric Logitech. Used a CCD sensor, digitally recorded images, and had a cable connection for download in the computadora.
IMAGE RESOLUTION The resolution of a digital camera is limited by the camera sensor that responds to light signals, replacing the work of the film in traditional photography. The sensor consists of millions of "buckets" that are loaded in response to light. Generally, these cubes respond only to a limited range of light wavelengths, due to a color filter on each. Each of these buckets is called a pixel, and uses a mosaicism and interpolation algorithm for linking the image of each wavelength range per pixel in an RGB image where the three images to represent a pixel full color.
IMAGE QUALITY The pixel count is usually all that is displayed to indicate the resolution of a camera, but this is a misconception. There are several factors affecting the resolution of a sensor. Some of these factors include sensor size, lens quality and organization. Many digital compact cameras are criticized for having too many pixels on the small size of incorporating sensor.Excessive pixels can even lead to a decrease in image quality. For every pixel sensor is so small that it takes very few photons, and thus the signal to noise ratio will decrease. This decrease leads to noisy pictures, poor quality in shadows and images generally of poor quality.It is estimated that the best compromise between the number of megapixels and image quality in compact cameras is achieved with six sensors megapixels.
COST PER PIXEL While technology has improved, costs have fallen dramatically. Measuring the cost of pixel as the basic measure of value for a digital camera, has been a continued and steady increase in the number of pixels bought by the same amount of money on new cameras is consistent with the principles of Moore's Law. This predictability of camera prices was first presented in 1998 at the PMA Australia DIMA conference by Barry Hendy and designated the Law of Hendy.
METHODS FOR CAPTURING IMAGES Since the first digital cameras were introduced to the market, there have been three main methods of capturing the image, according to hardware configuration of the sensor and color filters.The first method is called single-shot, in reference to the number of times the camera sensor is exposed to light passing through the lens. Single-shot systems use a CCD with a Bayer filter, or three separate image sensors are exposed to the same image through an optical system image separation.