The BBC's new history of photography isn't definitive- it leaves out too much- but it's insightful and full of nuggety bits of information. Fox Talbot invented the calotype because he couldn't draw. There are still people taking daguerrotypes because they love the intensity and the shininess. Nadar's direct and incisive portraits of artists have never been bettered (I'll second that). Pictures of crime scenes taken by turn of the century NYC policemen prove the inherent genius of the medium. While Edwardian artist photographers were pretending to be Whistler it was the careless, snap-happy amateurs, like Lartigue, who drove the medium forwards.