The 3 Basic Types Of Telescopes
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Since the advent of modern astronomy, scientists have come along a long way to build high powered telescopes. The earliest history of the modern telescope can be traced back to 16th century Netherlands. Today telescopes are available in various kinds, dimensions and shapes. The cost associated with each telescope differs widely and depends on the task it will be used for. Normally, astronomers agree that there are only two main types of telescopes. 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.
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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.
When the word telescope is mentioned, most people think of a refractive one. The far end is opened, and it slants downward to the opposite end, which is closed. 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 main advantage of the refractive telescope is that they are very easy to maintain. The tube is enclosed which keeps the glass surface protected from the outside elements such as heat, dust, and winds. The main disadvantage is that it suffers from chromatic aberration which is a defect that allows the light to form a rainbow around an image. With refractive telescopes, faraway objects can't be seen too clearly because the mirror creates light spectra around them.
On the contrary, reflective telescopes are more suitable to observe distant plants and galaxies. These are the giant machines that we see in famous astronomical laboratories around the world. Because of the advantages of the reflective surface, this type is now available for use in homes and smaller labs. Usually, a reflective telescope acts a light bucket where it traps the beam of oncoming light. 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. Maintenance cost of smaller telescopes is not factor that influence most viewers to use their telescopes compared to the huge advantages of using the telescope.
The third type, a compound telescope is commercially available for use and it might be a good starter telescope for novice and beginners alike. By merging qualities of the reflector and refractor, the magnification and view are enhanced. Knowing that, astronomers that are more advanced usually do not use compound telescopes. In addition to the above types, there are more advanced versions such as radio telescopes, x-ray telescopes, and others.
If you're new to astronomy, buy a high-end model of telescope based on the advice of a trusted expert in the field. Keep an eye on local stores that have telescopes. If you buy your first telescope locally, beware of low quality. Due to large scale production of telescopes, inferior quality materials are used which may cause a significant risk of malfunction. A professional shop should always provide a warranty so that it will be covered should any problems arise. 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 does telescope reviews to get them on the right track.