CCD Digital Camera

(CCD) A charge-coupled device is a device for the movement of electrical charge, usually from within the device to an area where the charge can be manipulated, for example conversion into a digital value. This CCD is achieved by "shifting" the signals between stages within the device one at a time. Technically, CCDs are implemented as shift registers that move charge between capacitive bins in the device, with the shift allowing for the transfer of charge between bins.

Often the device is integrated with an image sensor, such as a photoelectric device to produce the charge that is being read, thus making the CCD a major technology for digital imaging. Although CCDs are not the only technology to allow for light detection, CCDs are widely used in professional, medical, and scientific applications where high-quality image data are required.

DIGITAL CAMERA ZOOM

Digital zoom was used to make the middle photo from the top photo, while the lens was zoomed-in optically for the bottom photo. Typically, the digital zoom would not be available until after the optical zoom had been exhausted.

Digital zoom is a method of decreasing (narrowing) the apparent angle of view of a digital photographic or video image. Digital zoom is accomplished by cropping an image down to a centered area with the same aspect ratio as the original, and usually also interpolating the result back up to the pixel dimensions of the original. It is accomplished electronically, without any adjustment of the camera's optics, and no optical resolution is gained in the process.

When comparing the image quality achieved by digital zoom with image quality achieved by resizing the image in post-processing, one must differentiate between cameras that perform lossy image compression like JPEG, and those which save images in a lossless Raw image format. In the former case, digital zoom tends to be superior to post-processing because the camera may apply its interpolation before small details are lost to compression. In the latter case, resizing in post-production will yield results equal or superior to digital zoom.

Some digital cameras rely entirely on digital zoom, lacking a real zoom lens, as on most camera phones. Other cameras do have a real zoom lens, but apply digital zoom automatically once its longest focal length has been reached. Professional cameras generally do not feature digital zoom.

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-taken from Wikipedia-