Table of contents |
2 Notable Refracting Telescopes 3 See also: |
Technical Difficulties
For research purposes, refracting telescopes have become unpopular. They are criticized for their relatively high-degree of chromatic and spherical aberration. There is also the problem of lens sagging, a result of gravity affecting glass. There is a further problem of mis-refraction; caused by air bubbles trapped within the lenses. In addition, glass is opaque to certain wavelengths, and even visible light is dimmed when it passes through glass. Many of these problems are avoided by using reflecting telescopes.
A refractor telescope is a type of optical telescope that refracts light through a pair of lenses on either end of the telescope. While initially the most common type of telescope, these are today used primarily by amateur astronomers, and have been supplanted in professional work by reflecting telescopes. However, some relatively small instruments with 100-150mm objective lenses regularly produce astrophotography that rivals images created by professionals as recently as 20 years ago using what were then the largest telescopes on Earth.
See also: List of largest optical refracting telescopes (from which it is clear that their heydey was in the 19th century)Notable Refracting Telescopes
See also:
From Refractor telescope to be merged :