The Colorama was a large photographic display located on the east balcony inside New York City's Grand Central Terminal from 1950 to 1990. Used as advertisements by the Eastman Kodak Company, the photographs were backlit transparencies 18 feet (5.5 metres) tall by 60 feet (18 metres) wide. They were described as "The World's Largest Photographs."
References
Colorama (Kodak) Wikipedia(Text) CC BY-SA