Colour-composite picture of the NE side of the Hydra I cluster. N is up, and E is left. The size of the picture is 18.37 × 16.21 arcmin². In the upper left corner lies the HCG048 group, where the group members are labelled. In the lower right corner the other two bright cluster members, NGC 3315 and LEDA 087328 (see also Table 1) are marked. In addition, one of the UDGs detected in the cluster by Iodice et al. (2020a), UDG 4, is also marked in the figure.