Why did Pierre-Auguste Renoir and his friends paint in the forest of Fontainebleau in 1864?

In the spring of 1864, following the closure of the studio of their teacher Charles Gleyre, Pierre-Auguste Renoir and his fellow students—Claude Monet, Alfred Sisley, and Frédéric Bazille—moved temporarily to the forest of Fontainebleau.12

They went there to devote themselves to painting directly from nature. This move was driven by their shared dissatisfaction with the academic tradition, which emphasized historical or mythological subjects and required paintings to be finished in a studio. By working in the forest, these young artists sought a new freedom and experimentation in their style, adopting the practice of painting entirely out-of-doors to better capture the reality of their surroundings.12