MIRA NAIR’S best films throng with vivid characters jostling for position. Pictures such as Monsoon Wedding and Salaam Bombay! are unpredictable, pulsating, living organisms; her extended casts are the vital organs that feed the films. She would therefore seem the ideal director to tackle The Namesake, Jhumpa Lahiri’s sprawling multigenerational novel.

With a personal journey — Calcutta to America — which mirrors that of the book’s characters, Nair certainly has a touchstone for the story and its many questions of identity — cultural, social and generational.

And Nair’s instinct for lively, complex family dynamics is well served by the material. Still, although she is an obvious fit with the book and the logical choice to bring the Ganguli family to the screen, you can’t help but wonder if it is the wrong screen, and if, like Zadie Smith’s superficially similar White Teeth, The Namesake might have been better served by a television mini-series.

The family chronicle introduces us to Ashoke (Irfan Khan) and his wife-to-be Ashima (played by the Bollywood actress Tabu) with snapshots of their single lives in Calcutta. He’s a bookish student with a taste for the writings of the Russian author Nikolai Gogol. She’s a demure beauty and a singer in the classical Indian tradition. Their introduction, witnessed by beaming and expectant parents, is strained.

But Ashima chooses him for her husband on the strength of his American-made loafers.

Her culture shock on arriving for a new life in America is colour coded — the orchard of tropical fruit hues to which Ashima waves goodbye is replaced by the monochrome of New York in winter.

There is something about this gentle, formal couple struggling to find their place in a new world that quietly enchants.

But suddenly we’re whisked forward in time to the birth of Ashima’s first child, named Gogol by his father, then on again to a new home in the suburbs. Then the focus shifts to the adolescent Gogol (Kal Penn), necessitating a jarring tonal change from domestic drama to teen comedy. We rather lose touch with the parents in order to explore the son’s quandary, torn between home country and cultural heritage. It’s a shame because Ashima’s dignified disappointment in her life is the really interesting story.

There are plenty of moments of insight and honesty in The Namesake, but we’re covering too much ground too quickly. The result is emotionally dislocated and not entirely satisfying — a taster rather than the full banquet.