Left: GRAVITY H band Acquisition Camera image of the observation of J0529-4351 showing the quasar and AO/FT reference star. On sky the separation is 22″ but the VLTI optics bring them to GRAVITY in separate beams with a separation of about 2″. Right: averaged differential phase spectrum of J0529-4351 (blue points) across the Hβ emission line (black line). An initial BLR model fit to the line profile and differential phase (red line) shows a much smaller BLR and SMBH mass.