Above all, though, “The Curious Case of Benjamin Button” is a triumph of technique. Building on the advances of pioneers like Steven Spielberg, Peter Jackson and Robert Zemeckis — and on his own previous work adapting newfangled means to traditional cinematic ends — Mr. Fincher (“Fight Club,” “Zodiac”) has added a dimension of delicacy and grace to digital filmmaking. While it stands on the shoulders of breakthroughs like“Minority Report,” “The Lord of the Rings” and “Forrest Gump” (for which Mr. Roth wrote the screenplay), “Benjamin Button” may be the most dazzling such hybrid yet, precisely because it is the subtlest. While he does treat the audience to a few grand, special-effect showpieces, Mr. Fincher concentrates his ingenuity on the setting and the characters, in particular — and most arrestingly — on the faces of his stars, Cate Blanchett and Brad Pitt