Top: magnification probability distribution of each lensed image, i.e. the histogram of the pixels in the maps (see Fig. 1). Bottom: Kolmogorov–Smirnov statistic of each distribution pair (see Eq. (3)). In each case, the corresponding μ is indicated in the middle. The Salpeter and Chabrier mass functions have slightly deviated distributions. Small D_KS shows that the probability distributions are insensitive to the chosen mean stellar mass or IMF, but they are not independent of them.