Modulation transfer functions of the photographic material developer system, determined with a bar test-object

A study has been made of the modulation-transfer functions (MTF) of two photographic materials of different types with the use of a specially shaped bar test-object. Only when a developer with a high buffer capacity is employed is the MTF invariant with respect to the standard optical density level used in the numerical processing of the curves, and to the method of calculating the MTF. In this case the function concerned is the true MTF of the emulsion layer itself, determined only by the scatter and absorption of light in it.