Optical absorption spectra of amorphous Mn/SiOx, Cr/SiOx, and Cu/SiOx, cermet films, 300 nm thick, with compositions from 0 to 25 at % Mn, Cr and Cu, respectively, prepared by co-evaporation at 293 K in vacuo have been investigated. The linearity of (alpha HBAR omega)(1/2) versus HBAR omega graphs in the high absorption region for all the cermet films indicates that indirect photon transitions in k-space are involved in the absorption process. Tauc’s rule is also confirmed. In all cases the optical energy gap decreases significantly with increasing metallic content of the films and the width of the tail of localized states increases.