Pissarro, Richter and other masterworks up for auction in London A masterpiece by Camille Pissarro described as one of the most important impressionist paintings to come on the market in the last decade is one of the works going under the hammer at the Sotheby's Impressionist, Modern and Surrealist sale in London on February 5, while a week later the auction house will hold its Contemporary Art sale, with Gerhard Richter's 'Wand (Wall)' expected to fetch more than £15 million. Images and soundbites