The earliest surviving photograph, Nicéphore Niépce’s View from the Window Le Gras (1826/27), depended on a gradual tonal variation to give shape to the image. The work reveals that photography was born through the slow accumulation of light, where tone—not line—gives form to the world. Similarly, in Window, Pot, and Stove (1951), Roy DeCarava demonstrates how tone can be used to describe not just form but also an image’s visual rhythm, carried through a sequence of light and shadow The…