While surfing images of national parks on Google Photo Sphere, the Brooklyn-based Brea Souders stumbled upon a strange occurrence. People who had been present in the photographs, trekking through the American West, had been obscured by the algorithm, leaving only a ghostly silhouette, a shadow. Most hikers were not even on a trail or road. Intrigued by this meeting of algorithms and real life, Souders printed the reproductions and colored them, creating otherworldly 21st-century postcards. In “Vistas,” these works are on view, along with a selection of black-and-white photographs. —E.C.