Research for medical photographers: photographic measurement.

Many first degrees in photography or photography-related topics lack a thorough grounding in the photographic sciences. This in turn leads to difficulties for medical photographers who graduate from these courses, when it comes to designing photographic protocols for research projects that will utilize photography as a means of data collection. The concept of the image as subject analogue is introduced and means of visualizing the subject are outlined. The considerations for undertaking photometric, photogrammetric and time-based measurements are given. The variables that need to be controlled in each modality are highlighted and a bibliography is appended so that readers can discover for themselves working examples of the techniques described.