Cameron's technique was unorthodox. She purposely avoided the perfect resolution and minute detail that glass negatives permitted, opting instead for carefully directed light, soft focus, and long exposures (counted in minutes, when others did all they could to reduce exposure times to a matter of seconds). No commercial portrait photographer of the 1860s, for instance, would have portrayed Sir John Herschel (1792-1871)-the nation's preeminent scientist and mathematician, considered the equal of Sir Isaac Newton-as Cameron did in 1867. In Cameron's portraits, there are no classical columns, no piles of weighty volumes, no scientific attributes, no academic pose, for Herschel was to her more than a renowned scientist; he was "as a Teacher and High Priest," an "illustrious and revered as well as beloved friend" whom she had known for thirty years. It was he who had written to Cameron in Calcutta of Talbot's invention when the art of photography was in its infancy; and it was he who sent her the first photographs she had ever seen-scientific discoveries that were "water to the parched lips of the starved," she recalled. And so her image of him would be no stiff and formal effigy; she had him wash and tousle his hair to catch the light, draped him in black, brought her camera directly in front of his face, and photographed him emerging from the darkness like a vision of an Old Testament prophet. Her portrait is direct, unmediated by convention, recording faithfully, she hoped, "the greatness of the inner as well as the features of the outer man."
