Refractors (or Refractor) optical Telescope arrived on the scene in 1608 in Holland, its creation was achieved by three people namely Mr.Hans Lippershev, Mr.Zacharias Janssen and Mr Jacob Metius. It was Mr.Galileo Galilei who took the initiative and actually created the first version and the prototype was shown to the public towards the end of May 1609.
Design of the Refracting Telescope
Consisting generally of an objective lens and dual eyepieces, it is vastly superior to the human eye, greater focus and depth of vision giving the viewer a superior, brighter and magnified image. The telescope itself actually bends light, thus the creation of parallel rays which converge on a focal plane. Explaining this simply, the scope has its lens set at various angles which (when viewing an object) gives you an angular magnification and depending on the distance to the object a sharp image.
Types of Refractors
There is a selection of refracting telescopes available in the UK today and with this selection, there are many configurations from names like Celestron, Evostar, Orbinar and many more.
Disadvantages of Refracting Telescopes
Refractors are prone to a build-up of chromatic and spherical aberration, this short lens is likely to be affected over time. Colour fringing is another consideration to bear in mind especially on an F6 chromatic refractor.
You can potentially get what’s called Lens sagging, this is bought on by the centre of the large lens sagging due to gravity effects thus images viewed can be, to a degree distorted.
These are the primary (although not exhaustive) points of concern however all said it remains a popular scope with many advantages also.