CCD stands for Charge-Coupled Device It is a chip inside of any digital camera that takes the place of real film. Just like in a camera that uses film, light is exposed into the CCD and a digital image is recorded. Video cameras simply take enough pictures in a second so when they are played back, they appear to move, kind of like a flip book. Most consumer cameras are 1CCD which means that they only have one of these chips. Professional cameras have 3CCD's which results in a better picture quality. In a 3CCD camera, the light is split into Red, Green, and Blue and each chip records it's respective color. A 1CCD camera combinds all of these colors onto the same chip and therefore has less picture quality. 3CCD cameras are more expensive and aimed for professionals.
Read this post from wikipedia to explain in more detail:
Digital color cameras generally use a Bayer mask over the CCD. Each square of four pixels has one filtered red, one blue, and two green (the human eye is more sensitive to green than either red or blue). The result of this is that luminance 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 (3CCD) and a dichroic beam splitter prism, that splits the image into red, green and blue components. Each of the three CCDs is arranged to respond to a particular color. Some semi-professional digital video camcorders (and most professionals) use this technique. Another advantage of 3CCD over a Bayer mask device is higher quantum 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.
No comments:
Post a Comment