"Sometime before 1860 Grunewald added the wholly modern technology of photography to his list of skills and accomplishments. In that year he was paid ten dollars for a "photographic portrait" and ten dollars for "photographic portraits painted" as well. Although Grunewald is known to have occasionally supplied photographic portraits of his students in Bethlehem, his work as a photographer is otherwise not well documented." One of his photographs has a view that corresponds, “with slight modifications of detail,” to this painting. Grunewald used photography "to fully record a composition on-site and later translate it in oil on canvas with very little change in detail. This use of photography is quite at odds with Grunewald's training, in which the careful observation of details in nature was followed by an idealizing composition in the studio. Through his use of modern technology this idealizing is abandoned for a more exacting and scientific observation of nature."
From: Blume, Peter F. "Gustav Grunewald 1805–1878." Allentown Art Museum Publication, 1992. Page 26.