Spasm of m. corrugator supercilii under very strong light (left); A relaxed face (photographed in full sunshine) (right), between 1854 and 1855

Date: between 1854 and 1855. Dimensions: image: 22.9 × 16.9 cm (9 × 6 5/8 in.); ; mount: 40.3 × 27.6 cm (15 7/8 × 10 7/8 in.). Medium: albumen print. Collection: National Gallery of Art.