There are two ways I evaluate documentaries, my second favorite genre of film behind the movie musical. (1) Is the content compelling? (2) Is the presentation of the content compelling? There are plenty of documentaries that satisfy one and not the other. There are hours of Holocaust footage assembled into difficult-to-watch “documentaries” but that content isn’t presented with any artistry, most likely because it doesn’t require any. Andy Warhol’s docs are studied in film schools for their approach to the form (and Jonas Mekas’ camera work) but try sitting through Empire. Seriously. Try.
When the content and presentation are both compelling we find documentary genius.