Abstract: The invention relates to a method of determining the modulation transfer function of a recording support or of an optical system. In the context of the invention, an optical system includes any components with finite apertures which are required for forming an image of an object. A coherent-optically produced scatterer of known noise distribution or with a known spatial frequency spectrum is used for determining the required modulation transfer function. The modulation transfer function can be determined through the density of transparency distributions present on the recording support.