[Fe/H] vs. T_eff for the giants (log g < 4.2 dex). Top panel: H16 catalog, middle and bottom panels: our reanalysis with the ELODIE and MILES interpolators, respectively (blue dots). The solid red line connects the mean values and standard deviations of the metallicity in 250 K wide bins. The black dots show the location of the ELODIE and MILES library stars, in the middle and bottom panel, respectively. The mean [Fe/H] dispersion in [Fe/H] of stars taken in bins of 250 K for H16 is 0.076, for ELODIE is 0.075 and that for MILES is 0.079 calculated for stars with T_eff <  6500 K.