Histogram of absolute magnitudes of the 97 UCDs in the FORS field shown in blue. Histogram of the 19 point sources we detected within a radius of 300 pc around the UCDs is shown in black, if we assume they lie at the distance of the Fornax cluster. The dashed green line is a Gaussian with peak magnitude M_V = −7.3 mag and a dispersion σ = 1.23 mag, as measured for the globular cluster luminosity function of NGC 1399 in Villegas et al. (2010). The NGC 1399 GCLF is normalized to the number counts of the companions in the magnitude bin at M_V ≃ −6.5 mag. The average luminosity of the measured companion sources is M_V = −7.04.