in a career that has spanned more than that number of years, turns his attention to one of the world’s greatest ballet companies, the Paris Opera Ballet. John Davey’s camera roams the vast Palais Garnier, an opulent 19th century pile of a building: from its crystal chandelier laden corridors to its labyrinthine underground chambers, from its light-filled rehearsal studios to its luxurious theater replete with 2,200 scarlet velvet seats and Marc Chagall ceiling. “La Danse” devotes most of its time to watching impossibly beautiful young men and women — among them Nicolas Le Riche, Marie-Agnès Gillot, and Agnès Letestu — rehearsing the choreography of Mats Ek, Wayne McGregor, Rudolf Nureyev and Pina Bausch. For balletomanes and the curious alike, “La Danse” serves up a scrumptious meal of delectable moments, one more glorious than the next, made even more precious by their ephemeral nature.