The general problem of light scattering in turbid media has been studied often. Compared to the exact solution for plane-parallel diffusers, the Kubelka and Munk solution appears as an approximation. The photon diffusion model is also an approximate solution restricted to the case of low light absorption, for which the prior work of Silvy has been ignored. It gives interesting relations between Kubelka-Munk conventional parameters and the more intrinsic quantities related to the properties of the media introduced by the photon model. (C) 2003 Wiley Periodicals, Inc.