Selected by William A. Ewing , director of the Musee de L'Elys ee in Lausanne , Switzerland , and Nathalie Herschdorfer and Jean-Christophe Blaser , who are associate curators there , it surveys the state of photography through the work of 50 students or recent graduates of 63 art schools or university photography departments in the United States , Canada , Europe and , less frequently , elsewhere .