The Decisive Moment is a
photographic aesthetic/ technique conceptualized by the
French photographer
Henri Cartier-Bresson. It is the exact moment that all the
graphic elements of a picture
come together and the photographer takes the picture. Therefore, a photographer must be
ready at all times and wait for this
moment of perfection.
Cartier-Bresson, who started out as a
painter, was one of the founding members of
Magnum. In his book,
The Decisive Moment he wrote “"A
velvet hand, a hawk's eye-these we should all have...If the shutter was released at the decisive moment, you have
instinctively fixed a geometric pattern without which the
photograph would have been both formless and lifeless." He photographed
Gandhi on his
death bed, along with a slew of other major world events.
(http://www.icp.org/chim/bio/cartierb.html & http://photography.about.com/arts/photography/library/weekly/aa082399.htm)