Comparison of the Phosphoros-derived photometric redshifts z_ph, where the points show the photometric redshift estimate defined as the peak of the 1D marginalised redshift distribution, while the error bars indicate the 16–84 percentiles of the probability distribution function, with spectroscopic redshifts (z_sp) for sources in the A2390 field. The top panel shows the direct comparison, while the bottom panel displays the redshift residuals defined as (z_sp − z_ph)/(1 + z_sp). The normalised median absolute deviation (NMAD) and outlier rate (η) are indicated. Dashed lines at ±0.15 show the residual threshold.