Jhumpa Lahiri 's "The Namesake,” a novel about an Indian family torn between the old life in Calcutta, India , and the challenges of its new reality in America , could have proved too epic for a film-size condensation, but director Mira Nair makes seamless adjustments and films the saga of the Ganguli family with heart and intelligence.

The story begins in the late 1970s with Ashima (Bollywood actress Tabu) agre...