Magnitude–size relations for our samples. From left to right, panels show (a) the M_r vs. circular effective radius R_eff for our sz sample; (b) a comparison of the results in panel a to those of Shen et al. (2003; c) the M_r vs. semi-major axis radius, R_maj, for our sz sample; and (d) M_r vs. R_maj for our pz sample. The black circles show results for all the galaxies in a particular sample. Dark red and blue circles show results for the color-selected red and blue subsamples, respectively. Pink and light blue circles show results for the high and low Sérsic index subsamples, respectively. The error bars represent the dispersion of the maximum likelihood fits. In panel b, the red and gray triangles are data points from Shen et al. (2003). For ease of comparison, the shaded gray region in (c) reproduces the R_eff relation for the sz sample from panel a. The shaded gray region in panel d reproduces the result for all the galaxies in the sz sample using R_maj from panel c. We ensured that each M_r bin contains at least 100 galaxies. The bottom panels e–h show how the corresponding dispersion around each relation varies with M_r. In panel f, the dispersion found by Shen et al. (2003) is shown with a thin gray line.