Philippe Halsman (1906 – 1979) American portrait photographer.
He noticed that skipping forced his subjects to do more to focus on the look they wanted to give this gave them a different expression of their public image.
During the years that followed he finished all his photography sessions by asking the subject to jump, either Richard Nixon or Marilyn Monroe. These photos were compiled in a book called “Jump” published in 1959.
Definition of a classic: a book everyone is assumed to have read and often thinks they have. Alan Bennett