This is the fourth volume in the series Light Scattering Reviews, devoted to current knowledge of light scattering problems and both experimental and theoretical research techniques related to their solution. This volume covers experimental studies in the optics of light scattering media, focusing on single light scattering and radiative transfer. Light Scattering Reviews 4  summarizes recent developments in the fields of light scattering media optics and radiative transfer;  provides an up-to-date review of modern single and multiple light-scattering theory;  focuses on radiative transfer and optics of highly reflective objects, such as snow and ice;  uniquely covers numerical techniques in single and multiple light scattering;  considers both theoretical and experimental results;  presents the physical grounds of the opposition effects.