Observed X-shooter targets in the Sculptor dwarf spheroidal (black asterisks) plotted as height above the horizontal branch versus equivalent width of the two strongest CaT lines. The error bars indicate the error in the equivalent width based on the observed S/N in the CaT observations. The complete sample of CaT candidates within the Sculptor dwarf galaxy are overplotted as small gray circles. The black open triangles are stars observed in previous high-resolution work by Tafelmeyer et al. (2010). Overlaid as solid lines are the CaT calibration from Starkenburg et al. (2010), where the corresponding [Fe/H] values are marked.