Between 1885 and 1894 Le Sidaner lived the year round at the Etaples art colony and was joined there by his childhood friend Eugène Chigot (1860–1923), who shared his interest in atmospheric light. Later Le Sidaner traveled extensively throughout France. He also visited many cities around the globe, as well as villages throughout Europe. He exhibited at the Salon, the Galeries Georges Petit in Paris and the Goupil Gallery in London, and settled in Gerberoy.
Marcel Proust's mention of Le Sidaner's work in his novel In Search of Lost Time confirms its later reputation. In Sodom and Gomorrah, the narrator mentions that an eminent barrister from Paris had devoted his income to collecting the paintings of the "highly distinguished" but "not great" Le Sidaner.