Magnification probability for a case with ∑_eff/∑_crit = 2, in both parity regimes. This mimics the magnification probability of a hypothetical microlensing population consisting of 5 M_⊙/pc² stars and 20 M_⊙ pc⁻² PBHs. The critical density is ∑_crit = 2500 M_⊙ pc⁻². μ_t = 200 and μ_r = 4. Left panel: negative macro-magnification. Right panel: positive macro-magnification. The dashed curve represents the magnification probability for the same system with no PBHs.