Archived posting to the Leica Users Group, 2009/03/05
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Marc, The crossover dates from mm to cm and cm to mm are not 100% true. One case in point is the 50mm/5cm f3.5 Elmar which started life marked as 50mm. We had a very good discussion on this issue on the Leica Forum last year. By listing the lenses from some of the collectors on the forum we established some crossover dates for most of the lenses. It appears that lenses were marked in mm from the early Anastigmats of 1924 to the Elmars of 1932, and mixed mm and cm marked lenses in 1932 -1936. In 1937 Leitz started marking lenses in cm until the 1959/1960 period. Thereafter everything was marked in mm as it is today. However is doesn't really matter what Leitz called them, except to historians, as the focal lengths are the same. Len On Mar 5, 2009, at 12:09 AM, Marc James Small wrote: > At 11:56 PM 3/4/2009, you wrote: > >Would that make it, for those late ones, a special run. > >It doesn't seem that they would of been part of the general run. > > I do not believe so. Leitz changed from marking lenses in cm to mm > as noted during the 1960's. Leitz, as other manufacturers, > produced lenses in batches. So, at some point, a given batch of > 4/9cm Elmars was finished and the next batch, a year or so later, > was marked "4/90". Zeiss guys would go wild at this and would > hammer every possible serial number out of the woodwork to identify > the batches between which the change occurred. I am a bit more > relaxed on this and will simply say that I had forgotten how long > the 4/9cm or, if you wish, 4/90 Elmar remained in production. > Heck, there were even 573 LTM three-element lenses produced. > > I have let the LUG down twice over the past 48 hours, and I can > only apologize. Dum Iove nodat, and I have been napping a lot lately! > > Marc > > > msmall at aya.yale.edu > Cha robh b?s fir gun ghr?s fir! > > > _______________________________________________ > Leica Users Group. > See http://leica-users.org/mailman/listinfo/lug for more information