“I wanted the images to be less literal, more painterly,” illustrations editor Susan Welchman said when thinking how photographer Bill Allard might approach the coverage of our story on the Seine River that appears in the May issue of National Geographic. So she turned to the Impressionists as inspiration.

It was a natural pairing. Renoir, Seurat, and Sisley all painted the shifting light of the Seine. Monet had a floating studio on the river near Verteuil. Matisse’s studio at 19 Quai Saint-Michel overlooked the river where it embraces the Île St. Louis and Île de la Cité. (Both writer—who happened to be me—and photographer tried, unsuccessfully, to get into that apartment; the woman concierge who ferociously guarded the door