Comparison between the CaT metallicity estimates and the [Fe/H] values derived from spectral synthesis (SYNTH). The size of the points is a function of the S/N of the spectra. The two stars S08-75 and S08-59, which have been discarded from further analysis (see text) are identified with triangles. We highlight in red the stars which have been independently analysed with a classical method based on equivalent widths and which are in Fig. 7.