Photometric z_p vs. spectroscopic z for the sample of galaxies with z and 18 ≤ m_R ≤ 23 in the cluster field. Spectroscopic cluster members are indicated with black dots, galaxies selected within the 0.34 < z_p < 0.54 range and within the chosen m_R − m_I vs. m_B − m_V color−color cut (see text) are indicated with red (grey) dots. Galaxies outside the photometric and spectroscopic membership selection are indicated with blue crosses.