After having finished the C8 binoscope I still looked for something bigger
But with a C11 binoscope it begins to get tricky. Because of the bigger tubes you also need more backfocus to reach the interpupillary distance. But with the short light path inside the EMS systems it is still possible without problems, even it is close..
It starts again with 2 old Celestron orange tubes, just a little bit bigger as the last time...

I was lucky enough to find "Special Coatings" tubes, similar as with my two C8

Here are again the well known tube connection pieces

to be continued soon...