Mass functions of various open clusters. From top to bottom: ρ Oph (~1 Myr, Marsh et al. 2010); S 106 (~1 Myr, Oasa et al. 2006, their Fig. 10, middle panel for example); Trapezium (~0.8 Myr, Muench et al. 2002); IC2391 (~50 Myr, Boudreault & Bailer-Jones 2009); ONC (~5 Myr, Hillenbrand & Carpenter 2000); σ Ori (~3 Myr, Bihain et al. 2009); Hyades (~625 Myr, Bouvier et al. 2008); Praesepe (~590 Myr, Boudreault et al. 2010 and from this work). We also show the lognormal fit to the Galactic field star MF from Chabrier (2003) as a dashed line. All the other MFs are normalized to this at the substellar limit (~72 M_Jup).