Mean values of the internal precision to all objects (four upper panels) and mean values of the residuals from the iterative process (four lower panels) as described in Sect. 3 as a function of the magnitude. Each dot represents the mean of at least 13 000 points for the WFI (left panels) and 190 points for the SOI (right panels). The difference between the magnitudes of the points associated to a given dot do not exceed one. The corresponding magnitude in the X-axis is the respective mean magnitude.