Over-Under Refractor Binoscope

Has anyone built an over-under binoscope from refractors? Looks like it should work. Two 90 degree diagonals offset the light cones for each tube, the lower tube's upward at an angle, and the upper's down at the same angle for IPD, then one can view straight through, or add extra surfaces for 90 or 45 degrees.

Would such a system have any advantages or disadvantages relative to the usual side-by-side binoscope?

Jess Tauber

That always seemed like a good approach (and thanks for the example Thomas!). You only need two standard star diagonals, so it eliminates a lot of glass.

I suspect you'd have to design it for your IPD. A little rotation of the pair could vary this a bit, but then the exit pupil height would differ between the two.

Likely not user friendly during the day except for large distances. The views would be displaced vertically for close objects. With normal binoculars and close objects you get two images displaced horizontally, which gives you something close to the typical "movie view" through binoculars - two partially overlapping views displaced horizontally (nicely eliminated by the objective set up on the Pentax Papilio). Your eyes can obviously deal with this, but I think vertical displacement would be a impossible to handle.

Clear skies, Alan