[Chaos-l] Another idea.....pls advise

[Allen Davis]

You  just need now to get out and use it!  That is the best scope
.it is
almost a cliché
..but the best one is the one that is used!  allen

 

From: chaos-l-bounces at rtpnet.org [mailto:chaos-l-bounces at rtpnet.org] On
Behalf Of michelle s
Sent: Monday, May 23, 2011 11:07 PM
To: Jim Pressley
Cc: chaos-l at rtpnet.org
Subject: Re: [Chaos-l] Another idea.....pls advise

 

Well, I finally made a decision (it's returnable within 30 days for a full
refund) and went with the Celestron NexStar 130. If it's a mistake I will
know it after using it. I get the whole aperture idea (and I might be making
a mistake) but really would prefer a lighter weight telescope and also one
that helps us find out where things are. I might be exchanging it for the
xt8 later in the month, but at least I will be paying for return shipping on
an 18 lb. item, as opposed to a 40+ lb. scope. 

You have all been helpful and I will be referring to these emails if and
when I decide I don't like the Celestron. Free shipping, and it should be
here on Thursday! So....by Sunday, hopefully we will have spotted something
:)

Michelle

 

  _____  

From: Jim Pressley <binovision at gmail.com>
To: michelle s <shellytex1 at yahoo.com>
Cc: chaos-l at rtpnet.org
Sent: Monday, May 23, 2011 10:46 PM
Subject: Re: [Chaos-l] Another idea.....pls advise

Michelle,

The Celestron Nexstar 130 telescope's mirror is ~5" in diameter, with a
focal length of 650 mm.   The 8" Dobsonians discussed earlier are about 1200
mm in focal length.    There will be performance differences here...almost
an apples and oranges situation...that might better be discussed and
explained in person at a club meeting.    

 

For example, although the step between a 5" and an 8" mirror may seem
relatively small, their respective surface areas are 20 square inches (6")
and 50 square inches (8").   That equals an almost 2.5X increase in light
grasp.   In most cases, brighter is better.

 

It may come down to deciding which is more desirable...a 2.5X brighter image
or computer control to find objects.   Certainly, computer controlled
telescopes have merit...many of us use them...but you can enjoy learning the
sky by star hopping with a finder and star charts.  In fact, this is a great
way to learn the sky and can be a very satisfying pastime.

 

It might be best to simply hold off purchasing anything until you and you
son can attend an observing session and see first hand the differences in
various types of telescopes.    It's not easy to make an informed decision
without understanding the many options offered with today's modern
telescopes.

 

As several others have said, I too would go with aperture over features, but
everyone has to find out what they want for themselves.

 

Jim

                              
                            

 

 

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