A technique is described for measuring the modulation transfer functions (MTF) of recording media. In this technique, a coherent optical system interferometrically generates a signal suitable for recording on the medium being tested. A second coherent optical system is used to obtain the MTF; spatial filters are used to remove the effects of film-grain noise, phase errors in the emulsion of the film, and extraneous light distributions. Since both systems are coherent, this technique can be used equally well to measure the MTF of phase-modulated media or bleached photographic film. A satisfying feature of this technique is that the MTF is displayed at the output of the second optical system as an easily detectable light distribution.
A. VANDER LUGT and R. H. MITCHEL, "Technique for Measuring Modulation Transfer Functions of Recording Media," J. Opt. Soc. Am. 57, 372-379 (1967)