Hi everyone,
The 8'' F12 optics are a Fraunhofer design oil spaced doublet.
Barry Adcock imported the 2 x 8'' clear aperture glass blanks from a glass company located in Rhode Island U.S.A., then ground and figured the lenses
to perfection.
He then secured them into an aluminium tube (with focuser) of his design and construction.
Regards,
Andrew
blackcon@bigpond.net.au
0418 365 174