Performance of our fit for the SDSS-2MASS transformation. The top panels show an edge-on view on the colour-colour-colour plane for all 2MASS bands (J in the top-left panel, H in the top-middle panel, and K_s in the top-right panel). Our fits are always indicated by the dashed black lines. The bottom panels show the residuals of the fit shown as the difference between the observed magnitude and the magnitude derived from the fit depending on the apparent magnitude in the 3 2MASS bands (J in the bottom-left panel, H in the bottom-middle panel, and K_s in the bottom-right panel).