Schematic plot of the modifications made to the models in order to compare them to the ONC. The hatched area has artificial extinction of low-mass stars (i.e. stars with m <  5 M_⊙ are removed), the dashed ellipse demonstrates the scaling of low-mass stars along the y-axis by a factor of 1.5, the dotted circle illustrates the isotropic scaling of all high-mass stars, and the grey circle covers the central region where low-mass stars are left without scaling.