If you are an astronomer or if you just like to gaze as stars as your hobby, you would know how important telescopes are. These are the devices that let us see the world that is up there in the sky. The endless possibilities, all the constellations and the beauties that are up there cannot be uncovered without the help of telescopes. However, there are various kinds of telescopes that have their own purposes. Let us have a look at the various types of telescopes available and see what each one of them has to offer and what needs do each fulfil. You should know that there are primarily three kinds of telescopes, a refracting telescope, a reflecting telescope, and a catadioptric telescope.
A Refractive Telescope
A refractive telescope is that kind of telescope that has a convex objective lens at one end of the tube and an eye piece at the other end of the tube. This is the most basic kind of the telescope that has been used since the times when Galileo discovered the rings of Saturn and the moons of the planet Jupiter. A Refractor telescope is a very basic but is a very expensive telescope. This is because a refractor telescope tends to a provide a higher image contrast than a reflecting telescope.
A Reflective Telescope
A reflective telescope is such a telescope that does not use an objective convex lens like the refractive telescope, but it uses a concave mirror. It is to be noted that refractors are sealed tubes, however, the reflective telescopes are open at one end. The mirror, which is also called the primary, sends a cone of light up through the tube where a small flat mirror, that is called the secondary mirror, intercepts it and sends it to the eye piece that is located on the side of the tube. The advantage of a reflective telescope is that they are less costly than refractive telescope because they are easier to make than a refractive telescope.
A Catadioptric Telescope
A third kind of telescope is a catadioptric telescope. This is a special type of reflecting telescope that contains a correcting lens at the top and that correcting lens forms the image. Most of the catadoptric telescopes are of the Schmidt-Cassegrain design. A Catadioptric telescope works in a manner that the light passes through the corrector lens and then it is reflected off the primary lens and then off a curved secondary lens. Then finally it passes through a hole in the main mirror and then it reaches the eye piece.
All three kinds of telescopes are very good and are very important for anyone that knows and works with telescopes.
However, it is up to you that which one do you choose according to your preference. Many telescopes are available at TOG for you choose from.