LONDON.- The Michael Hoppen gallery announced an exhibition of work by one of Americas foremost fashion photographers Fernand Fonssagrives. Once the highest paid photographers in the world, he was ambivalent about the acclaim he received in his chosen field, preferring to remain anonymous. Little was written about him, even at the peak of his success. He was linked to the early Design Laboratory classes of Alexey Brodovitch, and was a key member of the close knit group of photographers now celebrated as The New York School. His most memorable work traces the unique partnership he had with his first wife, legendary model Lisa Fonssagrives,