Thanks guys.
I know what you mean about the PST hotspot, Peter. When I made the adapter for my SM40 and bought the B1200 I didn't expect to escape the hot spot so much as not have to change scopes on the mount in the obs. But the results with the SM40 through the ED80 are just so wonderfully flat and uniform I didn't keep my PST much longer... but I do miss its portability

.
The full disc is always a favourite Dennis. You'd almost think it deliberate wouldn't you?

I think my setup is well suited to it.
Al.