door Marc Dix » di 11 sep 2012, 19:59
Each pixel on a CCD can hold some maximum number of electrons. CCDs currently can hold from 25,500 to as many as 100,000+ electrons depending on the specific model of CCD. While integrating (exposing) an image, photons strike individual pixels and are converted to electrons and stored in each pixel well. The effectiveness of this process is referred to as Quantum Efficiency (QE). The number of electrons stored in each pixel ―well is proportional to the number of photons that struck that pixel. This linear response is one of the key traits that make CCDs exceptionally well suited to astronomical imaging.