What is the difference between a refracting telescope and a reflecting telescope ?
The Difference Between Refracting and Reflecting Telescopes The difference between a refracting and a reflecting telescopes.lifetips.com/”>telescope is in their optical construction. The refracting telescope uses a system of lenses to refract light rays, while a reflecting telescope uses a system of mirrors to reflect light rays. Reflectors are usually used to view brighter stars and planets.
A refracting telescope is like a sailors telescope, except that an astronomical one doesn’t have the extra prisms to turn the image up the right way, in order to get as much light in as possible. A reflecting telescope is shorter and fatter, and has a concave mirror at the bottom, which focusses the light into a small eyepiece in the side. For astronomy, the reflecting type is much, much, better.
A few years ago the choice, as well as the distinction, between refractors and reflectors was quite easy. In recent years though things have become a bit more difficult and ill defined. Speaking generally to start with, telescopes serve two basic purposes in astronomy; to gather more light than is possible with the human eye alone, and secondly to increase angular resolution so that we can see more detail in bright objects such as the Moon and planets. Refractors use purely lenses to gather and focus light. This is the traditional design of telescope. Unlike reflectors which have a slight obstruction to the optical path (caused by the secondary mirror), refractors have a clear aperture and so provide the best possible performance for their aperture. Refractors therefore provide true diffraction limited performance. One of the problems of refractors however is their tendency to show “false colour” or chromatic abberations. This is evidenced by the coloured fringes that can be seen. Achr
