by Bob MacGregor
Telescopes provide us with a powerful capability: to gaze at the stars with such magnification and clarity that we can examine them as much as we like. Any newcomer to astronomy may have their work cut out for them, since there are several types of telescope and each has its own advantages and disadvantages. Let's delve into optical telescopes and what to look for when buying one.
Refractor Telescopes
Refractors are amongst the most traditional forms and provide adequate viewing quality without having a premium price. It has a large objective lens at the end of the telescope and an eyepiece at the start. These gather more light than the human eye can, allowing for the creation of a focused and magnified image.
They're easy to use, reliable and have good clarity, though their portability comes into question with the larger sizes. The downside is that their design can lead to aberrations in the image. While focal length can reduce these problems, it will not remove them complete.
Due to the makeup of the lenses, they cause chromatic and spherical aberrations in the image. The most noticeable change is color fringing, though this can be reduced with increase focal lengths. Furthermore, defects in the glass-making process can leave bubbles behind, which become more noticeable when in use.
Reflectors
With a curved mirror as the primary surface of reflection, reflector telescopes create the image along a focal plane. Typically, this image is a certain distance between the mirror and focal plane and recording equipment can be placed there to capture the image. For real-time usage of the telescope, a second mirror can function in place of the recording equipment. Reflectors are known for focusing on large diameter objects.
While somewhat less prone to aberrations than the refractor, especially chromatic varieties, it can still suffer from such issues. The upside of the reflector is that it can use a correction lens to help reduce the number of aberrations present in the image. This comes at an increased cost, as does the reflector telescope as a whole, and can also be more difficult to set up.
Catadioptric
Unlike refractors and reflectors which use individual methods to provide the user with high-resolution images, the catadioptric systems utilize both lens and mirrors to produce the image. They have spherically shaped parts to induce a wider field of view and can reduce many aberrations in the produced image. Because of this, they're considerably more expensive than refractors and some reflectors.
However, the main benefit is that it's very easy to move around and set up. They make great investments and have a good mix of the previous types, although the image quality isn't quite as good. If image quality is paramount, then consider a large, high-end reflector or refractor depending on the objective.
With these three types in mind, it's much easier to pick and choose depending on what usage you want to get out of it. Price varies dramatically depending on brand, quality and size. Generally speaking, refractors are the cheapest and provide moderate resolution, reflectors provide great image quality, but are less portable and cost more, and catadioptric systems are very portable, very expensive and have a decent resolution. It's important to research the optical telescopes and what to look for when buying one.
Sneak a peek at our article for the low down on what to look for when purchasing a <a href="http://www.usedtelescopeequipment.com/buy/Optical+Telescope">Optical Telescope</a>. You will also get more info on how and where to find affordable <a href="http://www.usedtelescopeequipment.com">Used Optical Telescopes</a> online.
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New Unique Article!
Title: The Varying Models Of Optical Telescopes And What To Look For When Buying One
Author: Bob MacGregor
Email: ginjaninja101@hotmail.com
Keywords: optical telescopes,used telescopes,telescopes,microscope,monocular,binoculars,astronomy,space,science,hobby
Word Count: 550
Category: Hobbies
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