Models for the B ring (r_h = 0.58, τ_dyn = 2.2, left) and the A ring (r_h = 0.68, τ_dyn = 1, right) transparency versus elevation. The upper frame shows the transmission fraction T over sin B, as in Robbins et al. (2010), while the lower frames display the same as τ_phot versus B, following Colwell et al. (2007). Curves correspond to modelled maximum and minimum transmission over full range of ring longitudes. Size distribution models with W = 20 and ϵ_n = 0.1 were used. Points stand for B and A ring UVIS occultation data for different ring longitudes, traced from Figs. 5 and 6 in Robbins et al. (2010). Original UVIS data from Colwell et al. (2006, 2007).