Kormendy relation in the rest-frame B band (left panel) and R band (right panel). Red filled symbols are our 16 cluster ellipticals at z = 1.27 (upper panels) and evolved to z = 0 (lower panels) according to the passive luminosity evolution as described in Sect. 5.1 and reported in Table 4. The red lines are the Kormendy relation reported in Table 5 obtained by fitting Eq. (4) to our 16 ellipticals assuming the slope β at z = 0 (solid line) and leaving β as free parameter (dashed line). The open squares are the sample of early-type galaxies in the Coma cluster studied by Jørgensen et al. (1995a). The black lines represent the Kormendy relation at z = 0 derived from this sample and reported in Eqs. (7) and (8).