In black, median photometric errors for 0.5 mag bins for each of the six bands. Error bars indicate the 16 and 84 percentiles, mimicking 1σ error bars. In red we show the median differences between the primary and the secondary detections for each bin, with error bars indicating also their 16 and 84 percentiles. Red points are shifted 0.1 mag to separate them from the black dots to make them visible. The dashed horizontal line marks a 0.02 mag error level.