Re: Buyer Beware!

From: Eddie Trimarchi (eddiet_at_astroshed.com)
Date: 11/28/04 

Date: Sun, 28 Nov 2004 22:02:35 GMT

These limiatations exist in many short refractors.
My Synta 102mm f5 suffers similarly but is easily gotten-around with an
extension tube.

A 6" travel drawtube would extend half-way up the OTA when racked all of the
way in and would probably cause vignetting. With a CCD camera and filter
wheel on these scopes, you need focus to be racked all the way in. Mine
comes to focus about 1mm from being racked full in, so a 6" draw tube would
not be good in this situation.

I can use a MEade series 4000 barlow only if I add a 3" extension tube in
order to compensate for the missing diagonal which is needed to acheive
focus. But I imagine a short barlow in the diagonal should also work.

IMO by keeping the drawtube short, these scopes are more versatile than they
would be otherwise.

Eddie T.
http://astroshed.com
"Mayer Duda" <Mayer@duda.com> wrote in message
news:4Grqd.18526$VL6.15263@clgrps13...
> I have discoverd that the Celestron ED80 is not a good buy. The focuser
> is too short a travel to allow prime focus photography unless you can get
a
> longer 1.25" adapter. It is off by about 1"! Also you always have to use
> the 45 deg. diagonal to get focus.
>
> A 2X's barlow placed into the diagonal won't
> allow focusing on distant targets either, only closer range targets. It
is
> obvious that
> Celestron made a big mistake by only supplying the 3" travel focuser
rather
> than
> a 6". It is truly a spotting scope and can't be utiized for higher
> magnification
> astronomy. This must be the case for the Orion and Skywatcher 80ED's too
> unless they come with a 6" travel focuser.
>
>