Figure 1. The Hurter-Driffield(H&D) curves of the eight films included in this study are given. The optical densities (ODs) of the 21 steps of the sensitometric strips correspond to log relative exposure values (LogE) that range from 0 to 3, in steps of 0.15 each. In these figures, only the ODs for LogE
ge;0.9 (steps 7 to 21) are presented in order to enhance the visibility of the differences in the linear part and the shoulder of the H&D curves.