Some stories can only be told in the Big Apple, and the documentary on New York Times fashion photographer Bill Cunningham is one of them. Anywhere else, an old man riding his bike up and down city blocks, stopping to take pictures of passing strangers — mostly women — would be badgered by police.

But in the city that never sleeps?

The guy’s nearly as much an icon as Lady Liberty. The proof is in “Bill Cunningham New York,” as amiable as its focus, screening Thursday through Sunday at Oklahoma City Museum of Art. There’s no colon in the title, suggesting the two are forever linked, if not one and the same.

For more than three decades, Cunningham has taken to the streets on his original, red Schwinn, documenting the clothes that catch his eye. Well, you or I think of them as clothes; he calls them “the armor to survive everyday life.”

The spry, 80-something shutterbug wears his camera like others do a tie, and still uses real film to shoot his subjects. As he tells us in the doc’s opening moments, “The best fashion show is always on the street — always has been, always will be.”

Debuting director/cinematographer Richard Press does a marvelous job of showing Cunningham tirelessly at work — even when he’s greeted with a threat of “I’ll break that fucking camera!” — and the guy is always at work. He has never owned a television set; has no interest in food; and doesn’t see movies or listen to music. His job is literally his life, as evidenced by the miserly bed amid walls of file cabinets brimming with negatives and prints. As he puts it only half-jokingly, “Who the hell wants a kitchen and a bathroom?” Despite his longevity and profile, none of his colleagues and co-workers really knows anything about his personal life, if one exists at all. He’s such an enigma, audiences may grow skittish, wondering if Press’ profile of Cunningham will delve any deeper than surface level. (After all, both Press and producer Philip Gefter have worked with their star at the Times, so the doc isn’t purely objective.)

Have patience; in the final 10 minutes, the filmmaker finally gets him to sit still long enough actually to converse, and asks the questions that have nagged the viewer all the while. While Cunningham’s answers may not surprise, the moments are charged with palpable emotion.

“Bill Cunningham New York” bears resemblance to “The September Issue,” the 2009 documentary on Vogue editor Anna Wintour (who appears here), but the difference is this work is worth watching. Whereas Wintour has money and power, Cunningham has the personality.