The modulation transfer functions of different ground-glass screens produced by grinding or etching can be measured. Since screens of this type destroy the coherence of an optical beam, their transfer function can be measured by determining first the transfer function L0(ƒ) of an auxiliary lens including a planeparallel plate directly in front of the image plane, designed to simulate the ground-glass thickness, and then the transfer function L1(ƒ) of the auxiliary lens including the ground glass placed directly in front of the image plane. The transfer function of the ground glass is then given by the quotient L1(ƒ)/L0(ƒ).
Paul Kuttner, "Modulation Transfer Functions of Ground-Glass Screens," Appl. Opt. 11, 2024-2027 (1972)