 Portable Nagra sync-sound systems and unidirectional microphones, too, freed the documentarian from cumbersome audio equipment.A two-person film crew could now realize Vertov’s vision and sought to bring real truth to the documentary milieu.Unlike the subjective content of poetic documentary, or the rhetorical insistence of expositional documentary, observational documentaries tend to simply observe, allowing viewers to reach whatever conclusions they may deduce.