Types of Telescopes
There are a number of different types and models of telescopes, and to be honest I am just learning myself what the differences are.
For this article I am just going to concentrate on 2.
A Refraction telescope is to me anyway the traditional image of a telescope, its a long tube with a lens at one end and an eyepiece at the other.
Light enters the lens and this is focused to point f in the diagram, the eyepiece then magnifies this image for the viewer.
A reflector or Newtonian reflector is a telescope that uses mirrors instead of lenses.
Light enters the telescope at the top, then travels down the tube andÂ is reflectedÂ back up the telescope to a smaller mirror which then reflects this into the eyepiece.
Most astronomy would be done with this type of telescope as the aperture (base mirror diameter) can be made larger and cheaper than using a lens.