Double scopes

Hi all

One sees binoviewers, which split a single image from a telescope--say a 5 inch refractor--to both eyes. One sees binoculars, which place two tiny telescopes, say 30 or 40 mm each, one to each eye.

Why not take these observations a step farther and make a super-sized binocular, with (say) a pair of 75 or 85 mm refractors, one to each eye, on a common mount? Has anyone designed such a scope and mount assembly? Any experience on this list?

Ciao
Robert Howe

Hello Robert,

Check out this ad from Italy: "http://www.astromart.com/viewad.asp?cid=216855" and ask yourself if that's what you were thinking ?

Cheers,

Ed

Hi Robert (and Ed). I went to the trouble of obtaining a pair of Celestron SS80 f/5's and straight-through porro prisms (which were _very_ hard to find inexpensively), and designing a co-collimatable mounting system to align the scopes. The two porro prisms bring the EPs to within the normal IPD. Alas, they would not reach focus, so I need to either shorten the draw-tubes or find a shorter "collar ring"...

If money were no object, just get a pair of premium porro-prism spotting scopes and mount them +(O O)+ if you know what I mean. The challenge is to maintain perfect co-collimation at high power, with an eyepiece assembly that allows easy IPD adjustment.

If each scope were left-right reversed but top-down correct (refractor + star diagonal), you will get what's called pseudo-stereo on terrestrial objects -- a basketball will look concave :-) Astronomically it's not supposed to make a difference due to the great distance involved, but I haven't convinced myself of that yet ;-)

-- William

p.s. By the way, my mount design looks like O/\O where the left scope pivots on the / slope, and the right scope pivots on the \ slope, of the aluminum angle. The two scopes can be adjusted along orthogonal axes for co-collimation.

Robert,

That's not supersized. A binocular 20" Newt Dob, that's supersized, and has been done nicely. I had the chance to use one many years ago at Texas Star Party.

Clear skies, Alan