Liminal Image Size for Conventional Film Readers*
Henry I. Register, Alex G. Smith · Journal of the Optical Society of America · 1959
A total of 5000 photographic exposures of small targets of various contrasts have been made for the purpose of determining the smallest images which can reliably be detected in a standard film reader. In the majority of cases the liminal image size lay between 10−4 and 10−3 in. The study indicates that uncorrected predictions made on the basis of ordinary visual contrast discrimination data may be in error by an order of magnitude.