Portrait of Sir John Herschel, Julia Margaret Cameron, 1867
The reason why this portrait is out of focus is not because its maker was a ‘mere’ amateur unskilled in photography. Cameron deliberately adjusted her lens so that the image would not be sharp. In order to be ‘art’, a photograph should not merely copy reality as exactly as possible. Cameron is the most famous 19th-century photographer who used blurriness to achieve an artistic effect.