Resolving power of photographic emulsions

The resolution characteristics of typical panchromatic negative films have been studied with a camera using microscope objectives. The results of resolution measurements made with high and low contrast line targets and low contrast annulus targets, over a range of development times, are presented in this paper. Measurements were also made of the speeds of these films on the resolving power criterion. These show that the resolving power speed increases linearly with the gamma. The ratio of the minimum exposure permissible on the fractional gradient criterion to the exposure based on the resolving power criterion varies with the brightness scale of the subject