History of the telescope a wider field of view than a classic Cassegrain. During the period 1850–1900, reflectors suffered from problems with speculum metal mirrors, and a considerable number of "Great Refractors" were built from 60 cm to 1 metre aperture, culminating in the Yerkes Observatory refractor in 1897; however, starting from the early 1900s a series of ever-larger reflectors with glass mirrors were built, including the Mount Wilson 60-inch (1.5 metre), the 100-inch (2.5 metre) Hooker Telescope (1917) and the 200-inch (5 metre) Hale telescope (1948); essentially all major research telescopes since 1900 have been reflectors. A number of 4-metre class (160 inch)
Daniel K. Inouye Solar Telescope Daniel K. Inouye Solar Telescope The Daniel K. Inouye Solar Telescope (DKIST), is a scientific facility for studies of the sun under construction at Haleakala Observatory on the Hawaiian island of Maui named after Daniel K. Inouye, a US Senator for Hawaii. With a planned completion date of 2019, it is expected to become the world's largest solar telescope sporting a 4-meter aperture. The DKIST is funded by National Science Foundation and managed by the National Solar Observatory. Until 2013 it was known as the Advanced Technology Solar Telescope (ATST). It is a collaboration of numerous research institutions. The DKIST