GC candidates’ selection using the VI colour-magnitude diagram. The red diamonds are point sources from Misgeld et al. (2011) that are spectroscopically confirmed to be associated with Hydra I. These objects reveal the locus of GCs in the colour-magnitude space, and we use them to select our sample of GC candidates, shown as the black points delimited by the dashed polygon. The right panel shows the V-band luminosity function of our selected candidates and of the objects in the background field, normalised to the area covered by the seven FORS fields.