Re: [ATM] First telescope

[Ross Sackett <rsackett00@yahoo.com>]

--- Jean-François B. <rainbsoft@hotmail.com> wrote:
> I want to build my first telescope (newtonian) and
> I'd like to know if the 
> difference between choosing a 8" primary mirror vs
> 6" justifies the price 
> difference

J.-F.,

In my opinion, go for the 8".  There is a noticible
bump in brightness and resolution as you go from 6" to
8" apertures, without much increase in sensitivity to
air currents (unlike the increase from 8" to 10-12"). 
Subjectively, at least to me, the increase in cost and
modest increase in size-weight are small in comparison
to the better views.  

If you later decide to scale up to larger apertures,
you would want to keep your 8" as your grab-and-go
"weeknight" scope.  The 6", on the other hand, would
seem a little small and eventually you would probably
upgrade to 8", anyway, for your quick-look scope.

If you plan to grind your own mirror, the 8" might
have another advantage: I find that an 8" blank fits
my hands much more comfortably than a 6", and the
added mass is welcome.

Ross
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