State-of-the-art solar cells based on thin film silicon make use of random textures for absorption enhancement; in the past, the development of these textures was carried out empirically, and in most applications this is still the case. Attempts to understand light scattering at the internal interfaces rely on quantities like haze and angle resolved scattering that are only measurable in air and need to be extrapolated, normally by means of scalar scattering theory. In this context it is unfortunate that the description of scattering into air requires modifications with empiric parameters whose scaling is unknown. We present an alternate approach for predicting angular properties and intensities of scattered light which is based only on measurable quantities like the surface morphology and the refractive index dispersion, no adjustable parameters are needed.