As a widefield freak I was always interested in buying a Vixen SG 2,1 x 42 or a "Gucki" for low power widefield views with big aperture.
While playing around with some teleconverters to boost the power of binoculars I found out, that some teleconverters can be used like small telescopes.
Especially the Nikon TC-E2 was very promising with nice views and a big aperture of 54mm
So I bought two of these cheap at ebay.
Big aperture means big outside diameter, in the case of theTC-E2 this means 65mm
As my IPD is only 62mm I did mill 1.5mm away from each converter giving flat sides to join together both pieces.
I wanted it lightweight and smooth, so I decided to glue both converters together instead of milling a piece to hold them in place.
Sure it works only for my IPD, but this is part of the game :-)
OK, lets look at some pictures:
The astonishing thing with these converters is that they are sharp to the edge.
The field is around 27°, I could place the Big Dipper completely inside the field.
I have not yet been able to make a side by side comparison with the Vixen or the Gucky, but from my memory the "Nikon" is far ahead in any way.
54mm aperture are much more than the 42mm or 40mm of the "competitors" and the edge sharpness of them is not that good at all.
Actually I am waiting for some rubber eyecups to finish my work, but as the eye distance is quite huge they are already very usable.