after I have been building a really fantastic Borg 125mm ED binoscope earlier this year I had the feeling that I need some more binocular aperture and resolving power.
Bigger refractors are long and heavy, double-dobsons are also quite heavy and uncomfortable to use (at least in my opinion)
So I decided to go for a C8 binoscope, as it will be still quite small and lightweight and having a comfortable view from the back.
While using Matsumotos EMS I will get an upright and right sided view like in standard binoculars, so I also can use the double C8 for daylight viewing ;-)
Last week I got a second C8 tube and started my new project:
The left scope has already black velours inside, the right one has still the factory black coloring.
The difference is quite obvious...
Here now both scopes taken apart on the floor:
Here you can see how I machined the back to shorten the light path and to attach the Matsumoto EMS
And here you can see how the EMS-UXL will fit the scope - I would say perfectly :-)
The main problem in such a binoscope will be the long light path and the resulting needed backfocus.
A big backfocus will cause two things, vignetting at the baffles inside the tehelscope and spherical aberration because the Schmidt corrector plate is not calculated for a focal ratio of f/12 or even bigger.
The vignetting can be lowered by shortening the baffles.
Here you can see how I shortened the main baffle, I did not yet decide if I also will shorten the baffle around the secondary:
I hope you enjoy looking at my building process, and sorry for my poor englisch, I am German :-)