Julian Barnes, in Levels of Life quotes Nadar.
Nadar saw photography as one of the "three supreme emblems of modernity" (the others being electricity and aeronautics.)
With his bright red hair and beard, and a portrait studio interior decorated in the same color—the exhibition site in 1874 for a group of painters soon to become known as the Impressionists—he was a flamboyant showman.
According to Barnes’s schematics, Nadar was also "less interested in the horizontal than the vertical. His portraits surpass those of his contemporaries because they go deeper. He said that the theory of photography could be learnt in an hour, its techniques taught in a day; but what couldn't be taught was a sense of light, a grasp of the moral intelligence of the sitter, and 'the psychological side of photography—the word doesn't seem too ambitious for me.'"
Julian Barnes, Levels of Life