Magnification patterns inside the radial CC (left) and mass density fluctuations (right). Open blue circles mark the positions of negative mass density fluctuations, while open red circles indicate positive fluctuations. Positive fluctuations in the mass (both present in CDM and FDM) inside the radial CC lead to demagnification, whereas negative mass fluctuations (exclusive in FDM) can result in new critical regions. As we approach the centre of the halo, the negative fluctuations in FDM can compensate the increase in κ from the underlying NFW + Sérsic, fulfilling again the radial criticality condition, 1 − κ + γ ≈ 0.