Ok, following on from Mike's query a few weeks ago re extension tubes, I am going to get Steve from mogg adapters to see if he can tool it up.
I would estimate that at the moment, my toucam ccd is say 50mm away from the top lens surface, so i have another 50mm to go to get the televue stated 100mm for the 7.7x.
http://televue.com/engine/page.asp?ID=42
When they say top surface, i assume they mean the lens surface, not the top of the actual powermate.
Anyone have any more accurate measurements???
thanks