Hey guys, been reading this thread for awhile and I thought I could share some hopefully helpful links.
I bought my adapter from Ebay. This exact one:
http://www.ebay.com/itm/18mm-Female-to-18mm-Female-Glass-Adapter-/181430763475?pt=LH_DefaultDomain_0&hash=item2a3e1dbfd3
Personally I think it...