formula for calculating the brightness distribution of scattered light within the image of a directed light source, which is observed through a cloudy medium, is proposed. It takes into account the viewing geometry, the salient features of the light scattering properties of the medium, and their stratification along the observation path. The range of applicability of the proposed formula is determined by comparing it with the data obtained by the Monte Carlo method. The results of comparison show that this formula can be employed to describe the brightness of the image of the projector with the width of the angular distribution of light intensity θ02>0,4τ•β2, where τ is the optical thickness and β is the effective width of the light scattering phase function in a cloudy medium. In this case the distributions of brightness of the scattered light are adequately described within the viewing angles φ < θ2 when the angles of deflection of the axis of the angular distribution of light intensity from the direction toward the observer do not exceed 2θ2.