The location of the fields analysed in the present study (red circles) overplotted on an optical image of the Milky Way bulge (© Serge Brunier). The location of the fields discussed in previous studies (Zoccali et al. 2008; Hill et al. 2011) are shown as Z08 and H11; the location of the Ness et al. (2013a), Johnson et al. (2011), and Johnson et al. (2013) fields are shown as ARGOS, J11 and J13, respectively. The lower panel shows the colour−magnitude diagram for field HRm5m3. Red filled circles show the corresponding target stars for this field.