Re: [ATM] expert opinion

[A B <livedinspace@yahoo.com>]

Thanks for your reply. I know this is telescope making forum but I didnt know where else to look and ask. The problem is simple for me, I dont have time to build one myself.  However, I will be glad if someone can sell me his homemade telescope.


Sam

Tom Conlin <tomc@cs.uoregon.edu> wrote: Hi Sam,

I am no expert and have only lurked on this list for a year or so,
but I am not expecting you are going to get much feedback,
mainly because the question is not about making telescopes.
These folks concern themselves with small areas of a particular mirror,
or the coefficients of friction of exotic bearing materials.
By and large they avoid commercial scopes altogether.

That said, when you buy a commercial scope it is either the luck of the draw, or
you individually test and select the one you want. Machines can get lucky and 
produce fantastic optics, but on average you are going to get a "not bad" optic
that will dazzle you for several years. (unless they have bad quality control 
and you are really unlucky but then you should be able to return it)

If you have the opportunity to look thru the scope, learn all you can about
"star testing" first. If you can get your hands on the mirror
set up 'Ronchi test stand' and/or 'Foucault test stand' and take pictures.

If you have Ronchi/Foucault images of the mirror and you were to ask the list 
how to interpret them, you would get a ton of responses, cause that is what they 
do.

hope that helps and best wishes.

Oh and even a so-so optic is better than none :)

Tom

A B wrote:
> Hi All,
>      
>   Need little bit of help/expert opinion of everyone. I am thinking about buying this telescope. 
>   Does anyone have first hand experience with this telescope?
>    
>   http://www.telescopes.com/products/zhumell-10-inch-dobsonian-reflector-telescope-38399.html
>    
>   SAM

-- 
           ... nice weather     eh          tomc@cs.uoregon.edu



 
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