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Purchasing Telescope

Need our opinion on a telescope Optics Planet has on sale, go ahead and ask! Post some hints and tips on various telescope brands and configuration.

Purchasing Telescope

Postby jpc2010 on Thu Sep 09, 2010 4:37 am

Looking to buy. Interested in either the Celestron NexStar 90 SLT Computerized Telescope or a Celestron NexStar 102 SLT Telescope. The 90SLT has a Motorized Altazimuth mount design and the 120SLT has a Computerized GOTO mount design. What is the difference. Also, help with pro's con's with one over the other.
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Re: Purchasing Telescope

Postby Jne_K on Thu Sep 09, 2010 12:04 pm


If the model has SLT, it is a GOTO computerized scope. SLT means star locating telescope in Celestron lingo. Any GOTO scope is also, by default, a motorized telescope, too. The 90SLT is a GOTO (see the Celestron website), so your choice is really a difference in the optical systems - a 90 Mak vs a 102 mm short refractor. In general, more aperture means more objects seen, but a difference of 12mm between these two is not really significant. The Mak will be better corrected for color and will be definitely sharper at the edge of the field. Short focal length refractors at this price are especially weak in these two areas. On the other hand, shorter focal length means you can get lower magnifications with any given eyepiece and that can translate into wider fields of view. That's a plus for photography and large star clusters and nebulae. A Mak gives you higher magnification with any given eyepiece by virtue of its folded optics. That can be a plus for high magnification work like planets and double stars. If this is your first scope, you are likely to want to start on planets and that, then, would favor the 90.
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