Relative difference in the angular power spectrum of the convergence as a function of the number of steps per AMR cell during the propagation. The reference for the relative difference is taken as the angular power spectrum with eight steps per AMR cell. The convergence is computed using an infinitesimal method on a Healpix map with N_side = 4096 at z = 1.5. We see that we achieve numerical convergence when using four steps per AMR cell.