“To thine own self be true” – it’s an admonition and affirmation generally held in high regard, but it’s also one that can be difficult to live up to. In many instances, that’s attributable to not really knowing oneself in the first place. And, as this telling documentary from writer-director Andres Veiel reveals, that was very much the case where German filmmaker Leni Riefenstahl (1902-2003) was concerned. At the risk of profound understatement, this colorful, controversial yet innovatively brilliant German-born actor-producer-director lived what could best be termed “a complicated life.” As an impassioned devotee of the arts, she developed a stellar reputation for her work as an actress and filmmaker in such pictures as director Arnold Fanck’s “Storm Over Mont Blanc” (“Stürme über dem Mont Blanc”) (1930) and her own directorial debut, “The Blue Light” (“Das blaue Licht – Eine Berglegende aus den Dolomiten”) (1932). Her considerable talents, in turn, caught the attention of the leaders of the country’s emerging National Socialist (i.e., Nazi) Party, who were looking for someone to serve as a creator of propaganda films (even if they weren’t officially called as much at the time). Riefenstahl was thus recruited to direct documentaries about the landmark Nuremberg Nazi Rally, “Triumph of the Will” (1935), and “Olympia” (1938), a two-part production celebrating the glories of the Third Reich at the 1936 Berlin Olympiade. Through these works, the filmmaker significantly advanced her reputation as a documentary filmmaker, introducing never-before-seen innovations in cinematography. She relished these opportunities to showcase her capabilities, but it came at a price when the truth of Nazi atrocities emerged during World War II – incidents about which she claimed to have no knowledge until she began witnessing them firsthand as a documentary war correspondent in Poland in 1939. Disillusionment subsequently set in. But, when she was accused of actively helping to sanction such unspeakable brutality, she assertively recoiled, insisting that this was not her intent when she agreed to make her films (despite remaining “friends” with the perpetrators who hired her). “Riefenstahl” thus raises the nagging question, “In light of the foregoing, was she truly unaware or remarkably naïve and delusional?” Through a wealth of archive footage, including numerous interviews with the filmmaker, there’s plenty of evidence that cuts both ways: Did she willingly turn a blind eye to avail herself of the opportunity (and consequently believe her own hype)? Or was she shielded from the truth by her Nazi overlords to get the agenda-driven output from her that they were seeking? This unceasing ambivalence would become a ghost that would haunt her for the rest of her life, especially when skeptics and investigative journalists in later years raised hard questions about her role in the rise of the Third Reich. Riefenstahl’s vociferous efforts to defend her name and work reflect the intrinsic indecision that pervaded her outlook during the 50+ years she lived after the war’s end, an attribute whose nature almost comes across as surreal at times. Regardless of what one might believe, there would appear to be plenty of room for justified ambiguity here, much of it based in the filmmaker’s apparent inability (or unwillingness) to examine her own true self. This outstanding release thus illustrates how clear-cut answers to pressing questions like this may not always be readily available, a quality that provides decidedly riveting viewing, particularly through the deliberately ambivalent ways in which this story is told and documented. So was Riefenstahl a victimized pawn? A gullible idealist? A bald-faced, lying collaborator? That’s up to viewers to decide, especially since the protagonist herself doesn’t appear to have a response to any of these characterizations. To thine own self be true, indeed.