Visitors watch as British artist Ben Johnson retouches an area of his painting "Looking Back to Richmond...
Visitors watch as British artist Ben Johnson retouches an area of his painting "Looking Back to Richmond House" at the National Gallery in central London December 23, 2010. The painting, which shows Whitehall in central London from Trafalgar Square, is based on the 18th century Canaletto "The Stonemason's Yard". It is the first time a painting is being completed in public at the gallery, and forms one of three huge cityscape canvases in Johnson's show, "Modern Perspectives". REUTERS/Toby Melville (BRITAIN - Tags: SOCIETY IMAGES OF THE DAY)