Comparison of the observed and modelled pure Brγ line visibilities of our AMBER observation of HD 163296. From top to bottom: wavelength dependence of flux, visibilities of the first, second, and third baseline. In each visibility panel: (1) the observed total visibilities (red, green, blue, as in Fig. 1); (2) the observed continuum-compensated pure Brγ line visibilities (pink), and the modelled pure Brγ line visibilities (black; model MW6, Table 3) are shown.