The capacity of a reflecting surface to transfer contrast is governed by two parameters, “figure,” and microroughness. In the present study, highly polished surfaces were evaluated in terms of contrast or modulation transfer; it was found that only figure, not microroughness, accounts for a reduction in modulation transfer at higher spatial frequencies of object details.
JURGEN R. MEYER-ARENDT, "Evaluation of Plane Mirrors by Contrast Transfer," J. Opt. Soc. Am. 53, 812-815 (1963)