Refractor Telescopes

Products reviews and general guides for the amateur and hobby astronomer.
Helpful hints and tips for first time telescope buyers.

Home       Guides       Reviews

Refractor versus Reflector Telescopes

Comparative Merits of Refractor and Reflector Telescopes

If you are considering the purchase of a telescope, one of the first decisions you will want to make is whether to buy a reflector scope or one that's a refractor. At first glance, the differences seem pretty clear cut, but the distinctions between the two grow somewhat more subtle the more closely you explore the subject.

Let's start with the easy part: Refractor telescopes use glass lenses not unlike those found in eyeglasses, while reflector scopes operate with a series of mirrors. So far, so good. It is easy to distinguish between the two different types of telescope at a glance, because they vary significantly in appearance. The refractor scope is long and tubular and probably fits most people's stereotypical view of what a telescope should look like. Quite different in appearance is the reflector telescope, which is shorter and much larger in diameter than its refractor cousin. While the eyepiece for the refractor telescope is at its back end, the eyepiece for a reflector is generally on the middle or front of the optical instrument.

English astronomist/physicist Isaac Newton developed one of the world's earliest relector telescopes, a design that remains extremely popular to this day. The Newtonian scope uses two mirrors to focus ambient light into a conical configuration, with the first mirror establishing the cone and the second bending it so that it can be viewed through an eyepiece on the side of the telescope's barrel-like scope.
 

Far older in design is the refractor telescope, which focuses light entering the front or larger end of the tubular scope through a series of glasses lenses to deliver an image through the eyepiece that is located at the back or smaller end of the scope. One of the advantages of the refractor design is the absence of any obstructions within the body of the telescope itself. A telescope of this basic design is essentially the type that Galileo used to make his astronomical observations during Europe's Scientific Revolution in the late 16th and early 17th centuries.
 

Both types of telescopes have their champions, and each will argue passionately that the design of their favorite scope is far superior to the alternative. In the end the decision should be based on your own personal preferences and the type of celestial viewing you plan to do.

If you are going to be searching the nighttime skies for smaller and dimmer objects in space, then you will probably have better luck with a reflector telescope, which because of its broader design admits more light, enabling the telescope user to see smaller objects more readily than might be the case with the refractor. The latter, however, should be more than adequate for those who are content to limit their astronomical searches for larger, brighter objects, such as planets and stars.

If you find you just can't make your mind up, you might want to consider a compound telescope, which embodies the best of both designs. Alternatively, you may eventually want to purchase both types of telescope. As we've already observed, each has its own unique merits, and where the refractor may be a bit weak for some types of celestial observation, the reflector is strong, and vice versa.

 

Refractor Telescopes 2012