Spectroscopic success rate as a function of magnitude. Top: histogram of the observed H total magnitudes for all observed targets (dotted line), for secondary targets (long-dashed line), and for those with high-quality spectroscopic redshifts (full line). Bottom: success rate as a function of H total magnitudes over the whole probed redshift range (full line), and split according to band (dotted: H band or 1.3 < z_phot < 1.7; dashed: K band, or 2 < z_phot < 2.7. The long-dashed line shows the success rate targeting the [O III] line.