Tamron adaptall(1)was not a thread lens mounting system, it was very similar to adaptall2 actually which is sort of a breech/bayonet system.
The M42x0.75 mm threaded universal lens mounting system was/is called T-Mount, not adaptall. JC O'Connell hifis...@gate.net -----Original Message----- From: pdml-boun...@pdml.net [mailto:pdml-boun...@pdml.net] On Behalf Of Paul Ewins Sent: Wednesday, April 01, 2009 10:52 PM To: Pentax-Discuss Mail List Subject: Re: do any m42 adapters do auto stopdown? Yep, that has to be different. I did remember a couple of cases of a "different" M42 in the photo world - an early Adaptall type mount that is M42 x .75 and also a Schneider Componon enlarging lens that used an M42 x .75 retaining ring. Earlier and later versions of the same lens were different sizes (M39 and M50) which caused me much confusion. The Adaptall thread was the one that connected the various lens mounts to the lens rather than the lens to the camera. Paul > The tool page he reference was M42-5 not M42-1 > > JC O'Connell > hifis...@gate.net -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions. -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.