A Film Numbering Device For Numbering Sheet Photographic Film

摘要

Studies at the National Institutes of Health requiring large numbers of exposures on photographic film are being aided through the use of an optical numbering device (Illustration A) constructed around an electric digital counter, optical system, light source and an external photographic exposure timer. Programs depending on exposed film hare presented two difficult problems, namely, identification in order to maintain continuity and the filing of this film in a manner for future identification.