Computational time per phase curve point for n_ph=10⁴ and Rayleigh-scattering calculations. For a full phase curve with, for instance, 34 evenly separated points from 7.5 to 172.5° (as for Fig. E.1), the computational time is 34 times what is indicated in the plot. The curves correspond to different values of the single scattering albedo of the medium, ϖ, and the Lambert surface albedo, r_g.