Re: [ATM] Any focal length suggestions for 12" newt with Ethos eyepiece?

[hermit <hermit@outofoptions.org>]

Gil McFarlane wrote:
> I have some 12" blanks - a kind gift from Bill Kelley
> - that are calling me!  
>
> I have an order in for one of the new Ethos 13mm wide
> angle eyepieces - and I am thinking of customizing a
> scope for the eyepiece.  (I am trying to forget about
> the cost of the eyepiece - I have never spent more
> than 150 for any eyepiece - I normally use orthos and
> plossls).  Anyway, my parameters are:
>
> 1.  The scope will not create too wide an image cone
> for my 50 year old eyes.
> 2.  The scope will have as short a focal length as
> possible without requiring the use of a parracorr.
>
>   
f5.  You can build a dob and still not need a 'boost' to get to the 
eyepiece.  Even if  you are short, it can be built low to the ground and 
f5 seems to do well without added correction.

Ken Lowther
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