... Previous: Desmearing Solar System Objects in Chandra Data . ... We review the data reduction of two fiber-based echelle spectrographs (HEROS and FEROS) with emphasis on the similarity of the inconsistencies between the overlap of spectral orders before merging. ... The data suggest a very similar shift of the blaze function over all orders in the case of FEROS, leading to larger overlap mismatch in the narrower orders in the blue spectral region i.e., with larger gradients in the blaze function. ...