Bob
):-{])) <---- madden@netcom.com madden@svpal.org Remember amateur astronomers: "keep looking for the next Universe"
On Tue, 18 Apr 1995, Mark Suchting wrote:
>
>
> On Thu, 13 Apr 1995, Bob Bond wrote:
>
> > I've been kicking around the idea of making some 6" or so binoculars.
> > After thinking about it for a while, the idea of making them out of a
> > matched set of cassigrain optics seems to have taken hold. The obvious
> > advantages are compact tube length and a binocular "feel" with the lenses
> > out in front of the eyepieces. Gives them some style points, in my
> > opinion.
> >
>
>
> There was a good description in S & T in the 70's of a 6"F15 Cassegrain
> binocular, on a massive equatorial mount. The whole instrument weighed
> about 600 lbs ! It looked like a collimation nightmare....
>
> You really need a right angle bend at the back for comfortable viewing.
> This makes the optical path for a cass rather complicated. Why not build
> a dob binocular along the lines of the 6" F8's in S & T recently? I have
> built 8" f8's and they are very comfortable to use. It would be possible
> to view in the same direction as the sky if you used amici prisms in the
> place of the tertiary mirror.
>
> Mark
>