Upper left panel: K-band spectrum of MWC297 measured with AMBER, averaged across all baselines. Upper right panel: derived 2D photocenter displacement vectors for the Brγ line + continuum determined from our AMBER HR-K data. The black line shows the position angle of the disk major axis determined from our AMBER LR observations. Lower panel: differential phases for MWC297 observed with AMBER (circular points) compared with differential phases corresponding to the photocenter shifts shown in the upper right panel of this figure (black lines). The frame with PA = 39.6, BL = 102.4 is offset by 180° in order to see the differential phase changes at the Brγ line center.