Top panel: measured z_phot as a function of z_spec. z_phot = z_spec is plotted as a dashed black line. Four sources from our sample with ambiguous photometric redshifts have been ignored. We have also included two sources from outside our sample, AK03 and Vd-17871 (z_spec = 4.757 and 4.622, respectively), plotted as stars. These were fit photometrically in an identical manner and are included to improve the robustness of our fit. We detect a slight systematic offset with z_spec (Eq. (1)) plotted as a red dotted line. Bottom panel: Δz/ (1 + z_spec) as a function of z_spec. With data and Eq. (1) plotted as in the top panel.