Log of exposure; Unit of exposure (1985). Now called Log H on characteristic curves. A logarithmic scale of exposure is used on the horizontal axis of a characteristic curve graph, and the density values plotted against it are themselves log functions. A logarithmically numbered scale of exposure, shows equal ratios of exposure as equal distances along the horizontal axis.
References
Case, D., 1985, Motion Picture Film Processing, Media Manuals, Focal Press, London, Boston