The book is devoted to two aspects of the optics of scattering objects: consideration of the patterns of transfer of light radiation in highly turbid media (water, atmosphere, powders, fabrics, paints, etc.) and methods of spectroscopic analysis of matter by measuring the photometric characteristics of the radiation field scattered by the medium. The first part describes the essence of multiple scattering, the current state of the theory and experiment on radiation transfer in inhomogeneous systems. Particular attention is paid to unsteady scattering, scattering of narrow beams of light, the manifestation of nonlinear optical phenomena in the medium at high radiation densities. The second part of the book is devoted to the inverse problem of transport theory - illumination of modern methods for studying the optical properties of scattering objects. A detailed description of the equipment used to study light scattering is given.