Abstract: An X-ray film holder wherein a number of capacitive sensors are positioned and connect with circuitry for determining the presence of film in the holder and, when film is present, determining which one of several predetermined sizes have been placed in the film holder, plus whether the film is properly centered with such information used to provide control signals including a signal with a characteristic dependent on the width dimension of the film and a signal with a characteristic dependent on the length dimension. In addition, the circuitry provides a visible indication of the length dimension of the film placed in the holder for use in positioning the holder with respect to the X-ray source.