Photography is the most satisfactory objective way for the dermatologist to evaluate the response of inflammation to therapy. The method employed should be carefully documented so that it can be duplicated with succeeding photographs. Unless the same factors (film, lighting, and camera equipment) are used, the results will be of little value. Variations in technique will produce pictures of different quality.
Robinson HM. Photographic Evaluation of Therapeutic Efficacy. Arch Dermatol. 1968;97(3):258-261. doi:10.1001/archderm.1968.01610090030005