Same as Fig. 8, with the addition of empty contours for μ = 0.4, 0.5 and 0.6 (color coded in the legend) obtained with maximally spinning black holes (i.e. with ϵ₀ = 0.3 and r₀ = 1.24r_g). The dashed lines connect them to the non-spinning analogous realizations. Dark-red density spots represent the location of the center of different contours of the standard μ = 0.5 case, in which the only difference is the adoption of η (downward scattering component) varying among 0.4, 0.5 and 0.6, going from higher to lower , respectively.