Simulated illumination maps (20 000 × 20 000 pixel of 22.6 km side) produced on Earth by a source located at z₀ + z₁ = 1.18 kpc through a refracting cloud assumed to be at z₀ = 160 pc with a turbulence parameter R_diff(2.16 μm) = 100 km. Here R_ref(2.16 μm) ≃ 100 000 km. Top-left and middle: illumination produced at λ = 2.16 μm from a point-source with a zoomed detail; the contrast is 100%. The grey scale ranges from 0 to 4 times the mean intensity. Top-right: the same from a K0V star (r_s = 0.85 R_⊙, M_V = 5.9, at 1.18 kpc V = 16.3). The circle shows the projection of the stellar disk (R_S = r_s × z₀/z₁). Here the modulation index is only 3.3%, and the grey scale ranges from ±20% around the mean intensity. The bottom maps are the illuminations in K_s wide band (λ_central = 2.162 μm, Δλ = 0.275 μm), using the same grey scales as above. The modulation index is 55% for the point-source (left and centre) and 3.3% for the extended source (right). The two parallel straight lines show the sections sampled by two observers located about 10 000 km apart, when the screen moves with the transverse velocity V_T.