Distribution with respect to NB magnitude and Hα luminosity derived from the NB. We show NB candidates and sources with spectroscopy, including confirmed Hα emitters at the cluster redshift, foreground and background sources, and stars. The targets selected for spectroscopy are preferentially bright in the continuum and have bright emission lines. On average, the fraction of NB candidates followed up with spectroscopy and confirmed as Hα cluster members increases for bright sources and those with large Hα luminosities.