Archived posting to the Leica Users Group, 2007/06/23
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]thanks Don...that is remarkably lucid, and helps a lot. Steve On Jun 23, 2007, at 3:16 PM, Don Dory wrote: > Steve, > The DR and the "Rigid" Summicron are probably the same formula: we > have had > many a long discussion about this over the years. It is a seven > element > formulation which is very different from the current formula. In > essence, > the DR is the last of the high resolution relatively low accutance > designs. > The next formulation went for much higher contrast/accutance at the > expense > of some resolution. > > The confusion comes about because MTF charts are all about the > ability to > define square wave forms so the new designs are created for the > test. Older > designs would resolve much higher resolutions at admittedly low > contrast. > Think of a really long tail where even at very low contrast levels > you can > distinguish between two lines. > > On 6/23/07, Steve Barbour <kididdoc@cox.net> wrote: >> >> >> On Jun 23, 2007, at 12:26 PM, Leonard Taupier wrote: >> >> > Steve, >> > >> > The experts say the DR and the Rigid made at the same time ( 1956 - >> > 1968 ) are the same lens in formula and performance. >> >> >> so I have one further question and we can wrap this up.... >> >> are they in fact the same optically as the current !! summicron >> 50/2 and if not, how are they different... >> >> >> and yes I have read Puts and Gandy, and each time they seem more >> confusing, Steve >> >> >> > >> > Len >> > >> > >> > On Jun 23, 2007, at 3:20 PM, Steve Barbour wrote: >> > >> >> sorry Frank... >> >> >> >> >> >> this discussion is getting a little too deep for me... :-) >> >> >> >> >> >> is the cron 50 DR identical to the old rigid cron 50... of that >> >> era... >> >> >> >> >> >> or is it identical to the cron 50 which is available today ?... >> >> >> >> >> >> (as people say that the two are different from one another) >> >> >> >> >> >> >> >> thanks, Steve >> >> >> >> >> >> On Jun 23, 2007, at 12:11 PM, Frank Dernie wrote: >> >> >> >>> I mean contemporary with the one you own. >> >>> Frank >> >>> >> >>> On 23 Jun, 2007, at 13:49, Steve Barbour wrote: >> >>> >> >>>> >> >>>> On Jun 23, 2007, at 12:49 AM, Frank Dernie wrote: >> >>>> >> >>>>> The contemporary >> >>>> >> >>>> >> >>>> thanks Frank... do you mean the contemporary from then or >> >>>> now.... ? >> >>>> >> >>>> >> >>>> Steve >> >>>> >> >>>> >> >>>>> rigid Summicron is identical to the DR, apart from the close >> >>>>> focus arrangement. If you like the look so much why not get one >> >>>>> of those as well? >> >>>>> Frank >> >>>>> >> >>>>> On 23 Jun, 2007, at 08:29, Peter Klein wrote: >> >>>>> >> >>>>>> Steve: That was me. I had the idea of getting a cheap Rigid >> >>>>>> Summicron with bad glass and the correct focal length marked >> >>>>>> inside. The DR and Rigid lens heads unscrew from the mounts, >> >>>>>> so I thought I could put my DR lens head in the rigid mount >> >>>>>> for the M8, and still have the close range on film. I asked >> >>>>>> DAG about it, and he said that the mounts were different and >> >>>>>> it wouldn't work. But he also said that he could cut off the >> >>>>>> close focus part of the cam, and then it would work in the >> >>>>>> normal range on the M8. >> >>>>>> >> >>>>>> The unmodified DR does work in close-focus range on the M8. I >> >>>>>> know for sure, because I've tried it. When it's set in the >> >>>>>> normal range, the close-focus half of the cam sticks out too >> >>>>>> far, and it hits something inside the body when you try to >> >>>>>> mount it. I have read about this, and I have decided to >> >>>>>> believe it and not try it myself. :-) >> >>>>>> >> >>>>>> I'm still thinking about whether to have DAG do the >> >>>>>> "operation." It will depend on how much I like the 67mm >> >>>>>> equivalent length the 50mm turns into on the M8. And whether >> >>>>>> I want to desecrate a sacred object. Funny that I feel this >> >>>>>> way--I've used the close range all of twice since I got the >> >>>>>> lens. But another DR was my first Leica lens, way back in >> >>>>>> 1970. I really love how the DR draws, how it's made, how it >> >>>>>> feels. And it's a Wetzlar product from the Golden Age. So >> >>>>>> I'm reluctant to give the lens a "vasectomy" unless I'd really >> >>>>>> use it a lot on the M8. >> >>>>>> >> >>>>>> Decision postponed while I experiment with my other 50s. >> >>>>>> >> >>>>>> --Peter >> >>>>>> >> >>>>>> At 02:29 PM 6/21/2007 -0700, Steve Barbour wrote: >> >>>>>>> recall hearing that the cron 50mm DR can be modified, >> >>>>>>> so that it can be used on the M8 body... >> >>>>>>> maybe that was reported here... >> >>>>>>> if someone can substantiate this, and give me details, I'd >> >>>>>>> appreciate >> >>>>>>> it... >> >>>>>>> >> >>>>>>> thanks, Steve >> >>>>>> >> >>>>>> >> >>>>>> _______________________________________________ >> >>>>>> 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 >> >>>> >> >>>> >> >>>> _______________________________________________ >> >>>> 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 >> >> >> >> >> >> _______________________________________________ >> >> 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 >> >> >> _______________________________________________ >> Leica Users Group. >> See http://leica-users.org/mailman/listinfo/lug for more information >> > > > > -- > Don > don.dory@gmail.com > > _______________________________________________ > Leica Users Group. > See http://leica-users.org/mailman/listinfo/lug for more information