Investigation of clusters of galaxies. I. Explanation of photometric scale of errors by light diffusion in a photographic emulsion

A photographic photometry in B and V was performed for 326 galaxies in the central field of the Coma cluster. We found an explanation (diffusion of light in the emulsion according to an earlier investigation of ZIENER ) for the systematic deviation between the results from ROOD and BAUM and from GODWIN and PEACH in the V pass band. We conclude that the photometry of ROOD and BAUM is true. Diffusion also can explane the results of FONG , GODWIN , and METCALFE .