Photometric properties of the Lupus members and candidate members. Upper panel: I-magnitude distribution for Groups A and B (filled and blank histogram, respectively). Middle panel: (I, R − I) colour − magnitude diagram for the Lupus objects. Group A and Group B sources are indicated with open circles and dots, respectively. The thick solid and dashed lines are the 1 and 10 Myr isochrones, respectively, from the models by Baraffe et al. (1998). Lower panel: (J − H, H − Ks) colour − colour diagram for the Lupus objects. The thin dashed and solid lines correspond to the giant and dwarf loci, respectively, from Bessell & Brett (1988). An extinction vector of 5 mag according to the law by Cardelli et al. (1989) is also indicated. Other symbols as in the previous panel.