User:Vitosmo/CCD page

ORIGINAL PAGE IN WIKIPEDIA: Charged-couple device in Wikipedia

Color cameras
''Digital color cameras generally use a filter|Bayer mask over the CCD. Each square of four pixels has one filtered red, one blue, and two green (the human is more sensitive to green than either red or blue). The result of this is that information is collected at every pixel, but the color resolution is lower than the luminance resolution.

''Better color separation can be reached by three-CCD devices and a prism|dichroic beam splitter prism, that splits the  into,  and  components. Each of the three CCDs is arranged to respond to a particular color. Some semi-professional digital video camcorders (and most professional camcorders) use this technique. Another advantage of 3CCD over a Bayer mask device is higher efficiency (and therefore higher light sensitivity for a given aperture size). This is because in a 3CCD device most of the light entering the aperture is captured by a sensor, while a Bayer mask absorbs a high proportion (about 2/3) of the light falling on each CCD pixel.''

'''For still scenes, for instance in microscopy, the resolution of a Bayer mask device can be enhanced by  micro-scanning technology. Several frames of the scene are thereby produced. Between acquisitions the sensor is moved in pixel dimensions, so the one and the same point in the scene is acquired consecutively by parts of the mask that are sensitive to the red, green and blue components of its color. Eventually every pixel in the image has been scanned at least once in all colors and the resolution is therefore identical in all three color channels. This is called "color co-site sampling”.

Sensor sizes
''Sensors (CCD / CMOS) are often referred to with an imperial fraction designation such as 1/1.8" or 2/3", this measurement actually originates back in the 1950s and the time of Vidicon tubes. Compact digital cameras and Digicams typically have much smaller sensors than a Digital SLR and are thus less sensitive to light and inherently more prone to noise. Some examples of the CCDs found in modern cameras can be found in this table in a Digital Photography Review article .... ............''