Re: ATM Telephoto lenses as a small portable telescope...

["Fred Maxwell - No spam e-mail accepted." <fmaxwell@erols.com>]

Ken Lowther wrote:
> 
> On Fri, 30 May 1997, Jeff Crilly wrote:
> 
> > [Sorry for the length.. though some of this may be informative...]
> >
> > I came across a perfectly good (as far as I can tell) vivitar 200mm
> x 62mm
> > f/3.2 telephoto lens in the local used camera store's junk box for
> $5.  This
> > lens has the old screw type mount, and my understanding is that most
> > camera's today are bayonet (our nikon EM is bayonet) rendering the
> lens
> > undesirable.  As far as I can tell this is a two lens system: the
> objective
> > up front, and another small lens in the back.  Is this latter lens
> like
> > a barlow?
> >
> > My question for the list is... does it make sense to use such lenses
> for
> > visual astronomy?  Are there any hacks to improve them?  (note that
> it
> >
> 
> There are commercial adapters available. I have seen them advertised.
> Can't remember the source.

University Optics sells the adapters.  You use standard 1.25" eyepieces.
There are some optics in the adapters to move the focal plane back.  Get
them to send you a catalog.  They have some superb merchandise at very
reasonable prices.

Regards,
  Fred Maxwell