The MLEM tomograms, on the other hand, show a more robust reconstruction result, i.e. smoother layers without artifacts are obtained. However, the layer edges are blurred/averaged out compared to the FBP distributions. Since the average thickness is not affected by the use of the MLEM method, we conclude that this reconstruction method it well suited for reconstruction of XRD tomographic datasets of this type. For obtaining the highest crystallographic contrast, however, the FBP (or equivalent) methods are more suitable.