The trend away from 19th century  "picture perfect " academic art and the emergence of the impressionist movement seems to have coincided with the advent of photography.... Up until 1863 only academic art  was accepted into the Salon de Paris as the institution clung to the status quo

Salon des Refusés 1863

The Salon des Refusés of 1863, sanctioned by Napoleon lll, may very well represent the most decisive institutional development in the evolution of modern art. It is observed that it provided an opportunity for public exposure of the avant-garde and, marked the official sanction of the artist’s right to demonstrate the fruits of their labour without regard to institutional refusal or stylistic classification as opposed to the “Picture Perfect” requirement for the academic art of the day.

 

The Salon des Refusés further implied that freedom of exhibition was inextricably linked to freedom of pictorial expression and is the single most invigorating stimulus to the formation of the Impressionist group shows. 

 

Among the works exhibited were: Édouard Manet, James McNeill Whistler, Alexandre Cabanel, Gustave Courbet along with Camille Pissaro, Johan Jongkind, Paul Baudry, Fantin-Latour, Cézanne, Renoir, Carot and Diaz