Archived posting to the Leica Users Group, 1997/08/03
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]At 07:04 PM 02-08-97 -0700, Stephen wrote: >Well folks, after spending several hours with Modern, I found the >following: > [snip] >I believe the lens you're talking about is the rigid Summicron lens made >from 1953 to 1956 and having 4 of its 7 elements made from lanthanum >glass, a rare earth glass. I wrote to Leitz in Rockleigh, NJ about the [snip] > >THE INTERESTING THING about the above is that Modern stopped short of >saying they were EXACTLY the same formula, even though they could have >said so. Instead, Modern used "essentially the same" and "on average, >identical performance." Hmmmm. > >I am not sure, I have not been inside the lenses and compared each >element. But I am sure many people believe the formulas are slightly >different. My DR summicron was made in 1968. It therefore can't be exactly the same as the ones build between 1953 and 1956, since the composition of the glass was different. In fact, I don't think production of the DR summicron began until 1956 or 1957. Dan C.