The Pe Measurement is an index of the effective photoelectric absorption cross section of the formation. Since the measurement is only slightly affected by porosity and has a wide variance in readings for sedimentary rocks, it has become a valuable lithology indicator. Completely unfiltered, the Pe curve has very high vertical resolution on the order of two and one half centimeters. This high vertical resolution when presented on the log provides improved lithology information. Examples presented include a sand / shale laminated sequence, siderite nodules, pyrite and thin bedded mixed clastic / carbonate lithology.