There’s a lot to like in this lush tale of forbidden passion set against the backdrop of affluence and Bohemia in San Francisco. Sarah Polley plays a privileged daughter on the path to Harvard Law until, at a wedding, she is enchanted by a mangy, older photographer (Stephen Rea) who endears himself to her by referring to her as “Guinevere” and not snapping her picture. After some home dysfunction and uncertainty about her future, Polley moves into Rea’s studio and they coexist in romantic, artistic bliss — for a while. When Polley’s parents find out, they become irate, Rea descends into a Willie Loman rut and Polley discovers a succession of muse mugging. As the bullying, sharp mom, Jean Smart is a tour-de-force, worthy of an Oscar nod, and Polley’s delicate demeanor is the perfect hook to hang this taut picture on; that’s why it’s a real disappointment when the film’s conclusion unfurls as as whimsical, over-the-top wisp.