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RE: RE: RE: Appendix

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Posted by Robert May on October 17, 2000 21:01:06 UTC

The Celestron scope mentioned has a barlow/corrector lens at the end of the focuser where it`s fixed to the tube and this takes the very short FL primary and makes it into something that is a bit more usable. I`ve seen the scope but haven`t used it so I can`t say personally whethere it`s as good as the longer FL primary but considering the general Celestron quality, I would expect it to be a good preformer.
There is also the Tasco 4.5" reflector which doesn`t use a barlow and often has a spherical mirror (I`ve seen one example with a so-so parabolic mirror and quite a few with spherical mirrors) and that basically ends up being no good for anything over a few power. The scopes that I have viewed generally also have very small secondaries so that the EP only sees about 3.5" or so of the primary at any point.
The point I am making here though is that they are better than the refractors that they sell as the reflector is at least able to do a wider field of view than the refractors do.
If you are interested in a scope, I suggest that you spend just a little bit more money and get a 6" dob style scope and this will give you a better view from the larger mirror and you won`t be spending money on an essentially worthless German Equatorial tripod but rather on putting that money into the glass. Dobs are a very nice first scope as they give you enough light gathering ability without a huge cost of other designs. Thier only problem is that they need to be moved by hand on the end of the tube on occasion to keep something in view and, unless you put digital setting circles on one, you quickly need to know your way about the sky which means that you need a skymap to be able to get about the sky (something that you really need anyway).

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