Comparison between photometric and spectroscopic redshifts. Left: comparison between z_phot and z_spec for high-quality (Flag ≥ 3) redshift galaxies observed during the LBT campaign. Crosses show spectroscopic redshifts determined from the Hα line, circles with crosses from the [O III] lines. The dotted lines define the region outside which the z_phot is considered a catastrophic failure, defined by a redshift error |z_phot − z_spec|/(1 + z_spec)≥0.15. Right: same as the left panel, but comparing z_phot, SOM and z_spec. The values of σ_NMAD = 1.48Median(|z − z_spec|/(1 + z_spec)) and Bias = Mean((z − z_spec)/(1 + z_spec))) are also given, with z = z_phot in the left plot and z = z_phot, SOM in the right.