Scatter in the Δz values (red circles) and in the Δz/ (1 + z) values (blue triangles) for objects in a narrow redshift bin, as a function of the median redshift for the bin. The bins are built to contain a fixed number of objects (500), and they are not statistically independent since they partly overlap each other. The blue line shows the mean scatter derived from the blue points, with the (1 + z) scaling applied to it.