Study of Distortions in Statistics of Counts in CCD Observations using   the Fano Factor
  Factors distorting the statistics of photocounts when acquiring objects with low fluxes were considered here. Measurements of the Fano factor for existing CCD systems were conducted. The study allows one to conclude on the quality of the CCD video signal processing channel. The optimal strategy for faint object observations was suggested. 
I. V. Afanasieva
astro-ph.IM