The 3 Main Kinds of Telescopes

By Alan Armstrong

Since the beginning of modern astronomy, scientists have greatly improved in building high powered telescopes. The modern telescope's earliest history can be linked back to the 16th century Netherlands. Modern day telescopes come in different types, sizes and shapes. The price of a telescope is varies according to the functions it performs. Astronomers generally place telescopes into one of two main categories. They are refractive telescopes and reflective telescopes.

As the name suggests, refractive telescopes constitute a lens which gathers the beam of light and converge it on the surface of the mirror. On the other side of the spectrum, reflective telescopes disperse the beam of light that is spread across the surface of the mirror. Besides these two major types, there is also a pretty well known type, called a compound telescope. This type is actually a combination of the qualities of the reflective telescopes and the refractive telescopes. Combining these qualities may not necessarily mean that a compound telescope will be more effective. Each type of telescope has its good and bad points.

One typically thinks of refractive devices when considering telescopes. These have the far end open, and then slant towards the opposite, concealed end. Most people are very familiar with the appearance of this type, since it's often pictured in text books and similar places. This type can easily be found at any nearby store. The refractive telescope is advantageous because it takes little effort to maintain it. The tube is closed from both the ends which mean that the glass surface inside the telescope is protected from the outside environment such as heat, dust and winds. The biggest problem with the item is the characteristic defect known as "chromatic aberration" - in effect, the light creates a rainbow of colors around an image. That partially explains why refractive telescopes cannot view distant objects well, since the mirror may produce a dark image surrounded by a light spectrum.

On the contrary, it is easier to observe distant planets and galaxies with a reflective telescopes. In renowned astronomy labs all over the planet, you will find these gigantic devices. This type is now available to be used in homes and smaller labs because of the advantages of it's reflective surface. A reflective telescope works much like a pocket, in that it collects and holds the light radiating from the object it is pointed at. It is possible for viewers to make the object look bigger than their normal size by adjusting the objective mirror at the end from the trapped beam. The main disadvantage is to maintain the telescope as the mirror and related material is exposed to the outside environment. To most viewers, it is not a major factor influencing their use of the telescope, as the maintenance for smaller telescopes is not a problem large enough to outweigh its huge advantages.

The third type is commercially available compound telescope that is a good starter telescope for novices and beginners. It unites refractive and reflective qualities to provide better view and magnification. This being said, compound telescopes are not normally used by advanced astronomers. Apart form the above types, there are more advanced versions including radio and x-ray telescopes, among others.

For a beginner, it is suggested to look for a professional telescope outlet and buy after a getting a professional advice from an expert. Familiarize yourself with the local stores that carry telescopes. It is not a good idea to buy your first telescope from a local shop as the telescopes might not be of the highest quality. This is due to the large scale production of telescopes that has led to inferior material quality which in turn poses a significant malfunctioning risk. A professional outlet always provides warranty and guarantees to fix any problems. The cost of a beginner telescope varies from two hundred to twenty five hundred dollars. Because of this, look for telescopes in the over $400 range.

About the Author:

Alan Armstrong has always been fascinated with astronomy, even as a kid. To welcome people to the addiction of star gazing, he shows how buy telescopes to get them on the right track.