Abstract
The inhomogeneity of a medium affects its 'transparency', i.e. the contrast and resolution of an image which it forms. In Volume 2, parameters are discussed which characterize the inhomogeneity, namely the variance in permittivity and the correlation distance, also the general properties of correlations functions are presented. In Volume 3, the mechanism of light scattering, which is responsible for the loss in contrast, is studied. The calculation is performed for seven types of correlation function.