M42 lenses are 42mm dia. male metric threads with a 1.0 mm thread pitch. (t-mount are similar but have 0.75mm thread pitch)
that tool page is for something else very huge and different. JC O'Connell hifis...@gate.net -----Original Message----- From: pdml-boun...@pdml.net [mailto:pdml-boun...@pdml.net] On Behalf Of Larry Colen Sent: Wednesday, April 01, 2009 8:49 PM To: Pentax-Discuss Mail List Subject: do any m42 adapters do auto stopdown? The m42 lenses stop down by pushing in on the rod. The k-mount stop down by pushing sideways on a lever. I can imagine something where the widget that pushes sideway on a lever, would push on a hinged doo-hickey (pardon the technical engineering jargon) that then pushed on the rod on the lens. Does such an m42 to k-mount adapter exist? On a related note, is what we call m42 the same as what machinists call M42? http://www.besly.com/catl/catl4124ps.htm#M42 -- The fastest way to get your question answered on the net is to post the wrong answer. Larry Colen l...@red4est.com http://www.red4est.com/lrc -- 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.
