Jan van Eyck was a 15th century Flemish painter who was considered the greatest painter of his time. He developed oil painting techniques that made his works appear realistic and lifelike. Some of his most famous works include the Ghent Altarpiece and The Arnolfini Portrait. He was skilled at painting details like clothing, jewelry, and landscapes. Van Eyck may have used a camera obscura to help achieve precise accuracy in his works. His mastery of oil painting and use of optical devices made him ahead of his contemporaries.