Reflective Telescopes

Active Optical System Astronomy

Nicolas Zucchi 132, 170 made the first attempt to build a reflecting telescope in 1616, i.e. soon after Galileo developed the refractor. He states that he procured a bronze concave mirror executed by an experienced and careful artist in the trade and used it directly with a Galilean eyepiece. In order to avoid obstruction by the observer's head, his design introduced a significant beam deviation at the mirror, similarly to the front-view type later introduced by W. Herschel. Depending on the...