Learn about mirror surface measurement, precision, and extreme adaptive optics in this lecture segment from Kyoto University's public course on Physics and the Universe. Associate Professor Mikio Kurita from Kyoto University's Department of Astronomy discusses Chapter 5 of the presentation on Japan's first segmented telescope - the 3.8m Seimei Telescope. Recorded at the Centennial Clock Tower Memorial Hall on October 21, 2018, this technical presentation explores the advanced optical systems and measurement techniques used in modern astronomical telescopes.