In 1820, Hokusai changed his name yet again, this time to "Iitsu," a change which marked the start of a period in which he secured fame as an artist throughout Japan. His most celebrated work, "Thirty-six Views of Mount Fuji", including the famous "Great Wave off Kanagawa" and "Red Fuji" was produced in the early 1830s. The results of Hokusai's perspectival studies in "Manga" can be seen here in "The Great Wave" where he uses what would have been seen as a western perspective to represent depth and volume. It proved so popular that ten more prints were later added to the series. Among the other popular series of prints he made during this time are "A Tour of the Waterfalls of the Provinces", "Oceans of Wisdom" and "Unusual Views of Celebrated Bridges in the Provinces". He also began producing a number of detailed individual images of flowers and birds ("kachō-e"), including the extraordinarily detailed "Poppies" and "Flock of Chickens".