Archived posting to the Leica Users Group, 2008/12/09
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]P.S. I should have added to my earlier post on using the optical unit of a rigid 50 Summicron on a DR focus mount; the exact focal length of the DR, every DR, is 51,9mm, i.e. the focus mount is calculated for a focal length of 51,9; whereas the Rigids can come in a few different exact focal lengths, 51,9mm and others, e.g. 51,3mm etc (I'm not sure what the exact other focal lengths are). You can tell the exact focal length of a particular example of either DR or Rigid, it will be inscribed by hand on the black back retainer ring of the optical unit and visible when the unit is dismounted; on the Rigid but not the DR, the last two digits of the exact focal length are also engraved to the right of the rangefinder scale on the focus mount, i.e. for a lens focal length of 51,9mm will be engraved '19'; for focal length 51,3 will be engraved '13' etc. Obviously a DR (focal length 51,9) optical unit will not focus accurately on a Rigid focus mount engraved anything other than '19'. ----- Original Message ----- From: "Seth Rosner" <sethrosner@nycap.rr.com> To: "Leica Users Group" <lug@leica-users.org> Sent: Tuesday, December 09, 2008 2:24 PM Subject: Re: [Leica] M-lenses on M8 > Steve - and Sonny - take care; the only issue there is that the threads of > the Rigid Summicron focusing mount do not uniformly match the threads of a > particular optical unit. Some years ago, thinking to use the optical unit > of > my DR as a rigid, I bought a focus mount from Don Goldberg who warned me > about this and offered to take it back if it didn't work. It didn't. > Result > was that the optical unit, when mounted on the adapter and my M4 or M6 had > the diaphragm and rangefinder scales completely out of sight, a bit to the > right of bottom dead center. So a focusing mount might, or might not, > match > and align the optical head correctly. > > Best, > > Seth > > ----- Original Message ----- > From: "Steve Barbour" <kididdoc@cox.net> > To: "Leica Users Group" <lug@leica-users.org> > Sent: Tuesday, December 09, 2008 11:57 AM > Subject: Re: [Leica] M-lenses on M8 > > >> >> On Dec 9, 2008, at 9:43 AM, Sonny Carter wrote: >> >>> On Tue, Dec 9, 2008 at 8:45 AM, Steve Barbour <kididdoc@cox.net> >>> wrote: >>> >>>> >>>> and I know you are a DR guy... >>>> >>>> I did as Peter did...the DR on the M8, nice.... >>> >>> >>> Mine is up there too, getting surgery >> >> you'll like it Sonny, call it a DiRcumcision... >> >> a bit drastic at its age, but worth it. >> >> The other way to go is to remove the DR lens cassette, screw it into a >> matched Summicron Rigid body/M adapter, >> >> >> Steve >> >> >> >>> >>> >>> -- >>> Regards, >>> >>> Sonny >>> http://www.sonc.com >>> http://sonc.stumbleupon.com/ >>> Natchitoches, Louisiana >>> USA >>> >>> _______________________________________________ >>> Leica Users Group. >>> See http://leica-users.org/mailman/listinfo/lug for more information >> >> >> _______________________________________________ >> Leica Users Group. >> See http://leica-users.org/mailman/listinfo/lug for more information > > > -------------------------------------------------------------------------------- > > > > No virus found in this incoming message. > Checked by AVG - http://www.avg.com > Version: 8.0.176 / Virus Database: 270.9.15/1839 - Release Date: 12/9/2008 > 9:59 AM > > > _______________________________________________ > Leica Users Group. > See http://leica-users.org/mailman/listinfo/lug for more information -------------------------------------------------------------------------------- No virus found in this incoming message. Checked by AVG - http://www.avg.com Version: 8.0.176 / Virus Database: 270.9.15/1839 - Release Date: 12/9/2008 9:59 AM