A method of mass spectrometry is disclosed comprising automatically and repeatedly performing multiple cycles of operation, wherein a cycle of operation comprises the steps of: (i) mass analyzing first ions; (ii) exposing the first ions to a first photo-dissociation device to form a plurality of second ions and mass analyzing the second ions; and (iii) exposing the first ions to a first photo-dissociation device to form a plurality of second ions, fragmenting the second ions to form a plurality of third ions and mass analyzing the third ions.