R Scl image reconstructions based on different image reconstruction packages. For comparison, the top row shows the reconstructions based on IRBis (Hofmann et al. 2014) that we adopted as the final result (as shown in Fig. 9), followed by reconstructions based on (middle row) MiRA (Thiébaut 2008) and (bottom row) BSMEM (Buscher 1994). The MiRA reconstruction uses a UD fit as a start image, smoothness as regularization function, and does not use a prior. The BSMEM reconstruction uses the model atmosphere images as first start images and priors and is based on maximum entropy as regularization function. The MiRA reconstructions use double the pixel size compared to the other two reconstructions.