HST color-magnitude diagrams of 74 galactic globular clusters in the HST   F439W and F555W bands
  We present the complete photometric database and the color-magnitude diagrams for 74 Galactic globular clusters observed with the HST/WFPC2 camera in the F439W and F555W bands. A detailed discussion of the various reduction steps is also presented, and of the procedures to transform instrumental magnitudes into both the HST F439W and F555W flight system and the standard Johnson B and V systems. We also describe the artificial star experiments which have been performed to derive the star count completeness in all the relevant branches of the color magnitude diagram. The entire photometric database and the completeness function will be made available on the Web immediately after the publication of the present paper. 
G. Piotto, I. R. King, S. G. Djorgovski, C. Sosin, M. Zoccali, I.   Saviane, F. De Angeli, M. Riello, A. Recio-Blanco, R. M....