SPATIAL FREQUENCY CHARACTERISTICS OF REVERSAL RADIOGRAPH

Abstract

To improve the film graininess, we have tried the reversal development method. As the larger silver grains, which are more sensitive than smaller ones, are removed more than smaller ones from the emulsion of film in the process of bleaching, the graininess of the reversally developed film is much better than that of the original negative film. Film graininess is improved especially at the part of higher density of negative X-ray film. We investigated the modulation transfer function, autocorrelation function and Wiener spectra as to reversal and negative films. The results show that MTF of reversal and negative X-ray films are almost same and so depend only on the sensitivity of intensifying screens.