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发表于 30-9-2007 12:13 PM
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由于小弟是新手，所以明白在挑选望遠鏡时所面对的疑惑。。
首先必须了解各种望远镜结构的利与弊。。。（主要有3大结构：refractor, relector & catadioptric)
REFLECTOR
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Advantages:
- Reflector telescopes cost less to produce than other telescope types and offer the most telescope for the money. Reflector telescopes produce good images and are favored by astronomers who need the largest possible telescope to find distant, faint objects beyond our solar system (deep-sky objects). If you are thinking of giving a telescope that will allow room to grow in astronomy, a medium (four and a half inches or larger) reflector telescope is the least expensive way to go.
Disadvantages:
- Reflector telescopes are more fragile than other types of telescopes and need periodic readjustment of the telescope mirrors (a process called collimation) and, because they are open on the top (Newtonian reflector), the mirrors are exposed to dust and dirt and therefore need periodic cleaning. The reflector telescope is by no means fragile, but it is the least childproof telescope design. The telescope eyepiece, located at the top of the telescope, may also be more difficult for children to reach.
REFRACTOR
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Advantages:
- Refractor telescopes are virtually maintenance free since the telescope tube is closed (not open as in a Newtonian reflector) and there is no telescope mirror to adjust. The refractor telescope is the most rugged telescope design and in the most expensive versions, a refractor will produce the brightest and sharpest image per inch of telescope. The refractor telescope is a good choice for children, not only because it is rugged, but also because the telescope eyepiece is located at the bottom of the telescope where it easier for small people to reach. Refractor telescopes are also easier to use as a daytime telescopes (with an image erector) than reflector telescopes.
Disadvantages:
- The refractor telescope is the most expensive telescopes per inch of telescope size; beyond three inches, the refractor goes up very quickly in price. If you buy a beginner a small refractor, be advised that the beginner may quickly outgrow it if they stay with astronomy for long.
CATADIOPTRIC
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Advantages:
- A Schmidt Cassegrain telescope offers some of the advantages of a refractor - durability and less maintenance - but at price that is lower. The main advantage of an Schmidt Cassegrain telescope is portability - even a five inch Schmidt Cassegrain is small enough to carry on the front seat of your car. A Schmidt Cassegrain is regarded as the best all-purpose telescope for an astronomer who will be mixing visual observing with photography.
Disadvantages:
- A Schmidt Cassegrain telescope has a mirror in the front that partially obstructs the field of view and causes some light to be lost. For this reason, you may notice a slight darkening at the center of the field of view, though the effect on performance is negligible. Schmidt Cassegrain telescopes do not produce images quite as bright as the best reflector telescopes or an image quite as sharp as the best refractor telescopes, but it's versatility is better than either.
Question:
- What are Maksutov-Cassegrain telescopes?
Answer:
- Maksutov-Cassegrain telescopes, like the Schmidt-Cassegrain telescopes, are catadioptric telescopes (a telescope with lenses and mirrors). The difference between the Scmidt Cassegrain and the Maksutov-Cassegrain is in the shape and size of the corrector plate (lens) at the top of the telescope. The Maksutov-Cassegrain uses a heavier, more complex corrector plate.
Question:
- What are the advantages and disadvantages of a Maksutov-Cassegrain telescope?
Answer (Advantages):
- The Maksutov-Cassegrain telescope corrector plate allows for very fine correction of its optics. The Mak is capable of superb image quality, second only, perhaps, to the finest refractor. The Maksutov-Cassegrain is also a great design for smaller telescopes and is very popular for spotting scopes.
Answer (Disadvantages):
- The corrector plate on a Mak is heavier and more costly to produce. Maksutov-Cassegrain larger than 7 inches are, therefore, rare.
明白自己所要达到的目的（观测行星或深空天体，天文摄影等。。。）及预算，再考滤它的便携性。。
需要了解的是我们应该选择一个最适合自己的望远镜， 而不是最好的。。。
希望这能让各位和我一样想入门的新手有一个大概的概念。。。 也请各位前辈分享经验。。 |
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