The magic behind the camera
A digital camera as opposed to a film or videotape camera, uses a sensor address to transform images (or video) into electronic data. Modern digital cameras are typically multifunctional and the same device can take pictures, videos, and / or sound.
In 2005, digital cameras are starting to push traditional film cameras in many markets. The decrease in device sizes have recently allowed miniature digital cameras to be included in multifunctional devices such as cell phones and PDAs.
Classification
Digital cameras can be classified into several groups:
Camcorders
* Cameras professional video, as used in the production of television and film. These typically have multiple image sensors (one per color) to improve the resolution and color range. Professional video cameras often have a built-in VCR or microphone.
* Camcorders used by amateurs. This is a combination of camera and video to create an all-in-one production unit. Usually include a microphone to record sound, and have a small LCD Watch the video during shooting and playback.
Cameras
Digital cameras are generally characterized by the use of flash memory and USB or Fire Wire for storage and transfer.
Most have a rear LCD for reviewing shots. They are classified in mega pixels, ie the product of their maximum resolution dimensions. The actual transfers to a host computer and are made using the mass storage device USB class (so that the camera appears as a drive) or using the Picture Transfer Protocol and its derivatives.
All use a CCD (Charged For Coupled Device) which is a chip composed of a network of phototransistors to sense the intensity of the light through the focal plane of the camera lens.
Recently there has been any application of a second type of chip called CMOS (Complementary Metal-Oxide Semiconductor) sensor, and this chip is often differentiated from a CCD manufacturers adequate because it uses less energy and other light-sensitive material, however the differences are highly technical and many consider the CMOS chip a charged coupled device. For our purposes, a sensor is a CCD chip.
* Standard Digital Cameras: This encompasses most digital cameras. They are characterized by ease in operation and easy to focus, this design allows for limited motion picture capability. They have a great depth of field.
This allows objects multiple depths to be in focus simultaneously, which accounts for much of its ease of approach. It is also part of the reason professional photographers find their images flat or artificial-looking. They excel in landscape photography and casual use.
* Digital SLR sensor typically have a nine times greater than that of a standard digital camera, and are aimed at professional and amateur photographers. They appear to be common in most professional cameras ways replaceable components with flash and lens, which give the user maximum control over light, focus and depth of field.
They are also more voluminous and more expensive than its occasional use oriented counterparts. They are excellent for portraits and artistic photography because they can be customized for various applications with a wide range of interchangeable lenses.
Professional modular digital camera systems
High-end digital cameras used by professional back devices are usually separated from the camera bodies that are used. (This is because most large systems and medium format camera professional use at the time of digital capture exceeded the film as the professional of choice were modular in nature, ie the body of the chamber were multiple lenses, viewfinders, winders and backs available for use with that suit different needs.)
Since the back were first introduced, There have been three main methods of "capturing" the image, each based on the hardware configuration of the back in particular.
The first method is often called "Single Shot", referring to the number of times the camera sensor is exposed to light passing through the lens of the camera.
Single shot capture systems use a CCD with a Bayer pattern filter in it or three separate CCDs (one for each of the additive primary colors Red, Green and Blue) that are exposed to the same image through a beam splitter.
The second method is known as "Multi-Shot, because the sensor is exposed to the image in a sequence of three or more openings of the lens opening. Several methods for implementing the multi-shot technique.
The origin most common was to use a single CCD with three filters (once again red, green and blue) passed the sensor in sequence to obtain the additive color information.
Another multiple injection method used a single CCD with a Bayer filter but actually moved the physical location of the sensor chip in the focal plane of the goal of "stitches" together an image of higher resolution than the CCD would allow otherwise. A third version combines the two methods Unsealed Bayer filter on the chip.
The third method is called "Scan" as the sensor moves across the plane of focus very similar to sensor of a desktop scanner.
These CCDs are usually referred to as "sticks" instead of "chips" as they use only a single row of pixels (more properly "photosites") which are again "stamped" with the Bayer filter.
The choice of method for given capture is of course, depends largely on the issue. Usually inadequate to try to capture a moving subject (such as people or moving objects) with any thing but a draft system.
However, superior color fidelity and larger file sizes and resolutions available with multi-shot and scan the back make them attractive for commercial photographers working with stationary subjects and large-format photographs.
Webcams
* The cameras Web cameras are connected to computers, used for video conferencing or other purposes. Webcams can capture full-motion video as well, and some models include microphones or expand capacity.
These devices range in price from very inexpensive to expensive high-end models, and many have webcams a complex servo can follow basic facial movement with the help of software.
Interpolation
Color image or interpolation of the resolution is used unless the camera uses a single beam splitter approach shot, three-filter multi-shot approach, or Foveon X3 sensor.
The specific software for the camera interprets the sensor information to obtain a full color image. This is because digital images, each pixel must have three intensity values light, one for red, green and blue. A normal sensor element can not simultaneously record these three values.
The Bayer filter pattern is normally used. A 2×2 Bayer filter pattern is a pattern of light filters, with the Greens in the opposite corners and red and blue in other places.
The high proportion green benefits from the properties of the human visual system, which determines the brightness mostly green and is much more sensitive to the brightness of the hue or saturation.
Sometimes a 4-color filter pattern is used, often participation of 2 different shades of green. This provides a wider range of colors but interpolation process requires a bit more complicated.
The color of the luminous intensity values not captured for each pixel can be interpolated (or guessed) the values of adjacent pixels that represent the color is calculated.
In some cases the extra resolution is interpolated into the image by moving out of photosites a standard grid pattern so that photosites are adjacent to each other at angles of 45 degrees, and the three values are interpolated from "virtual" photosites which fall into the spaces at angles of 90 degrees from the actual photosites.
Connectivity
Many digital cameras can connect directly to a computer data transfer. USB is the most widely used, although some have a Fire wire port.
Integration
Some devices, like mobile phones integrated digital cameras. Mobile phone cameras are much more independent that sell digital.
Storage
Digital cameras need memory to store data. The larger pixel size goes, the more memory is needed. Chambers of use removable memory card to store data and cameras, but the cheaper and smaller, they can simply use fixed internal memory instead. Some cameras come with built-in memory too.
Autonomous devices
A standalone device such as a PictBridge printer, operates without need for a computer. The camera connects to the printer, which then downloads and prints its images. Some DVD recorders and television sets can read memory cards too.
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Digital Camera
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