When considering a goodly portion of Woody Allen’s filmography, Matthew McConaughey’s career-making quip from “Dazed and Confused” springs to mind: “That's what I love about these high school girls, man. I get older, they stay the same age.”

In too many of Allen’s movies, the men are middle-aged or older, and the women are invariably pretty young things, barely nubile. In his latest, “Magic in the Moonlight,” the customarily implausible romantic leads are the 54-year-old Colin Firth and the 26-year-old Emma Stone.

Allen’s age-defying chauvinism first reared its ugly head as far back as Manhattan, but at least that film had the moral protection of being a masterpiece. Magic in the Moonlight is far from it. It’s fairly amusing, it looks gorgeous, and it affectionately evokes movies from another period, but it’s as inconsequential as anything he’s ever directed.

It’s set in the Jazz Age, where Firth plays Stanley, an irascible illusionist who performs as a hilariously offensive Asian stereotype named Wei Ling Soo. As soon he de-wigs, we see, as his solitary friend puts it, his has “all the charm of a typhus epidemic.”

A friend, fellow-magician Howard (Simon McBurney), offers Stanley a proposition: Stanley, being a famous debunker of fraudulent spiritualists, should visit Howard’s relatives in the south of France, who are entranced by a medium. Prove she’s a charlatan, he challenges Stanley. Stanley drops everything to meet the professed psychic Sophie (Emma Stone).

Stanley is immediately taken with Sophie, and they are an agreeably disagreeable rom-com pair: a grouchy man of science and a starry-eyed woo-woo; when she calls a sunset landscape “beautiful,” he calls it “transient.” And the more time he spends with her, the more she seems to know about his past, gradually breaking down his rationalism and forcing him to believe in something beyond himself.

Magic in the Moonlight is at its best when Firth and Stone match wits and gently spar—when we, along with Stanley, try to determine her fraudulence or legitimacy.

Magic in the Moonlight is showing at the Broadway Theater, 111 E. 300 South, SLC.