Re: GPC-102ED by Vixen

From: Jim Johnson (jameswilliamjohnson_at_yahoo.com)
Date: 11/29/04 

Date: 29 Nov 2004 11:56:39 -0800

"Stephen Paul" <spaul219@hotmail.com> wrote in message news:<L56dnaz0I6kRWDfcRVn-uQ@net1plus.com>...
> With all this tripe and hype about triplet apos, I'd just like to speak up
> on behalf of all those long focus ED scopes put out by Vixen, and anywhere
> else from whence well figured lenses and well designed OTAs come.
>
> I can't imagine that a 102mm F9 scope can get much better than the Vixen ED.
> Not saying a scope can't be better... just can't imagine it.
>
> The only reason left to go with a triplet that I can fathom, is to get the
> focal length down. However, the Celestron/Vixen 102F9ED that I bought
> recently, is light enough to use with my UniStar Light Deluxe and has a wide
> field at 2.5 degrees, so I'm not going to rush out and spend twice the
> money, to get a shorter tube. This Vixen 102/920 optical tube weighs in at
> mere 8 lbs. There's a bit of torque in its length, but only bothersome at
> high power on the UA USLD mount. For high power planet observing, there's
> the Vixen GP on wood legs that came with it. More than capable for this
> scope.
>
> So, go ahead with all your bantering over which design is best if it makes
> you feel like you know more than the other guy, but the simple fact is, a
> well figured long focus ED doublet is nothing at which to turn up your nose.
>
> Stephen Paul
> (Convert to the first order of the almighty apo. Whether it be a fast
> triplet, or a long focus ED doublet... it's all good. And since I've some
> experience with both, I can honestly say that I ain't just whistling
> Dixie.).

I would guess that the 3 element apos are suited for shorter focal
length photographic/imaging uses and not just visible.

Jim Johnson

Relevant Pages

  • GPC-102ED by Vixen
    ... With all this tripe and hype about triplet apos, I'd just like to speak up ... I can't imagine that a 102mm F9 scope can get much better than the Vixen ED. ... well figured long focus ED doublet is nothing at which to turn up your nose. ...
    (sci.astro.amateur)
  • Re: Scope test; $800 Chinese beats $2800 Stellarvue
    ... be made in Japan and the rest of the scope in the US. ... No, there has been no leak from Meade, on condition of anonymity, like is ... I'd be more comfortable with a triplet from Japan, for sure, but I don't ...
    (sci.astro.amateur)
  • Re: Star test of Orion 100mm ED
    ... >This is exactly the type of star test pattern that my ED100 shows. ... >is due to the particular optical design of the scope - something to do ... It's a MYTH that all so-called apos show identical ...
    (sci.astro.amateur)
  • Re: Pics from 8" APO v. lowly SCTs
    ... attached to very nice and big APOs (such as a TMB designed 8" scope) that are okay but not in the same class as those from 12" and larger ... But otherwise, a larger objective has an edge for showing detail, and a longer focal length helps too. ...
    (sci.astro.amateur)
  • Pics from 8" APO v. lowly SCTs
    ... I've seen planetary pics from webcams and dedicated ccd cameras ... attached to very nice and big APOs (such as a TMB designed 8" scope) ... that are okay but not in the same class as those from 12" and larger ...
    (sci.astro.amateur)