The b→sγ quark process implies FCNC (flavour changing neutral currents) transitions which are not allowed at tree level in the SM, thus it only occurs via penguin loop. Hence, they are particularly sensitive to new heavy particles contributing in the loop, which allows to probe much higher energy scales through precision measurements. In these transitions, as a consequence of the $W$ chirality and the momentum conservation the photon is predicted to be almost entirely polarized, which opens the possibility for a sensitive null test of the SM. In this seminar an overview of the most recent results on radiative decays at LHCb will be given.