Walker Evans (American, St. Louis, Missouri 19031975 New Haven, Connecticut)
[Subway Passengers, New York City], 1938
Gelatin silver print; 12.2 x 15.0 cm (4 13/16 x 5 15/16 in.)
The Metropolitan Museum of Art, New York, Gift of Arnold H. Crane, 1971 (1971.646.18)
http://www.metmuseum.org/Collections/search-the-collections/259975
This is relatively short depth of field. The artist chose to shoot this photo in short depth of field because the main focus is on these two persons. He wiped out distraction from the background.
Walkers Evan [ couple at Coney island, New York] https://www.metmuseum.org/art/collection/search/265145
The artist used a long depth of field because the focus is on whole photo: landscape and couple
