B-luminosity–radius relation (L_BRRs) of our model galaxies with M_B(T_G) equal to 10⁶, 10⁸, 10¹⁰, and 10¹² M_⊙ (from bottom to top). For each mass two lines are shown: one with the original radii (dashed black line) and the case with the radii decreased by a factor of 4 (line made of filled black squares; see text). The models are compared both with observational data from Burstein et al. (1997) from GCs (magenta dots) to Dwarf Galaxies (blue dots), to ETGs (red dots), GCGs (light blue dots), and the ETGs by Bernardi et al. (2010, red dots, which overlap the previous ones). The agreement for the smaller radii case is soon evident (see the text for more details).