Re: ATM Alternatives to Newtonians

[iss@pvtnetworks.net]

>> Does anybody make Gregorians any more?

>The final instrument is physically
>longer and the final effective focal ratio is usually very long compared
>with a cassegrain.

IIRC  there was a 'folded' Gregorian shown in S+T that used a 
small diagonal mirror facing away from the Newt focuser, the focus was
at at the first focus of the concave Greg tertiary which was mounted
on the OTA opposite the focuser. The second focus was at the focuser
with the converging beam passing around the secondary. I think it would
be possible to have a Newt config as well by moving its sec and the focuser
closer
to the primary.