Relative flux (Eq. (2)) at a wavelength, λ = 7μm, of the spherical approximation (batman) compared to the diffuse opacity of a 1D (Table 1) atmospheric simulation (Pytmosph3R) (see Fig. 2 for the schematics). The effect is similar in the case of a 2D day–night (Table 1) simulation (Pytmosph3R) without rotation (i.e., N_𝒯 = 1). The same effect holds true in 3D cases, since the opacity of each case will decrease with the altitude, although it will be dominated by other effects.