Top panels: LFI measured beams (full line) for two individual detectors at 70 GHz (left, 18S; right, 20S) compared with the corresponding joint best-fit retrieved patterns (dashed line); the left panel is representative of a good fit (high variance δ), and the right one of a poor fit (low variance). These are the same detectors used to illustrate the LFI-only fit in Fig. 16. Bottom panels: difference in power between the above patterns, integrated up to a given radial angle, as a function of that angle; the difference between the measured patterns and the RFFM patterns (initial condition) is also shown (red curves). We note that Detector 20S is quite anomalous and was not used in the joint retrieval; indeed both the RFFM and the LFI-only retrieval models are better fits to the data than the joint retrieval.