Effect of beam smearing on the RC. The dashed line indicates the high-resolution model, where all the light is supposed to come from the disc, with the M/L that varies as described in Sect. 5.2. The solid line indicates the model after accounting for the effect of the beam smearing: the velocity is computed for apertures of 2.5″, with a slit aligned with the major axis. The dots correspond to the model on the actual apertures of the Hα dataset and their colour indicates their cosine of the azimuth in the galaxy plane.