Abstract
Applied infrared photography has changed significantly during the last 40 years. Its medical application has dwindled while its overall use has increased dramatically. An understanding of the electromagnetic spectrum and the relationship between what humans are capable of seeing and what infrared sensitive film can record will lead to a better appreciation of this film's potential application in today's world. Improvements in processing have resulted in greater film speed and the direct conversion of the film to positive transparencies. This latter development will aid individuals who use the film as an educational teaching aid.