This photograph of construction workers casually eating their lunch on a skyscraper beam suspended high about Manhattan is one of a series that can lay claim to being among of the 20th century's most recognisable images.
Yet, in the run up to its 80th anniversary today it has emerged that, far from catching the subjects unaware, it was set up as publicity shots for the Rockefeller Centre.
The identity of the photographer of the most famous image - Lunch Atop a Skyscraper - is unknown. He or she was among a pack of snappers sent by news agencies, including Associated Press, to cover the event at the RCA Building. Another, less celebrated, image shows the workers pretending to be asleep on the beam.
Ken Johnston, chief historian and archivist for Corbis Images, which owns the rights to the most famous photo, said: "The image was a publicity effort by the Rockefeller Centre. It seems pretty clear they were real workers, but the event was organised with a number of photographers." The photograph was taken on September 20, 1932, during the construction of the RCA site which forms part of the Rockefeller Centre.
Johnston said Lunch Atop a Skyscraper was probably "the most recognisable" of Corbis' 20 million-strong catalogue and is its "biggest selling historical image".