Archived posting to the Leica Users Group, 2001/11/28
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Dan: I wish I knew. I've not seen that before. I will make a guess but remember it is pure guess: the 39 was on the lens at birth, meaning 53.9 (although I don't recall ever seeing a number that high). Then the lens was rebuilt, perhaps in order to be a dual range, and became 51.9 N(ew)? Just conjecture. Can't figure out what else it might be. The fact that the second set of numbers is of a differrent size makes me wary that it may not have been the factory that did it. I also wonder if you have noticed any problems with focus? If the lens head is misfitted, your photographs should be somewhat out-of-focus. John Collier is correct though: you need to have the lens examined by a really competent repair facility that knows what it is doing to regularize whatever is going on with your lens. Incidentally, what is the serial number? There were two changes in the DR/Rigid Summicrons: the coating was changed on the later lenses and improved to enhance contrast. And the focussing mount was also changed. The first series has the grooves that are cut into the focussing ring on the outer raised surfaces of the ring; with the later lenses, the grooves are cut into the indented scallops of the ring. I'm not sure that the changes took place simultaneously not what were the serial numbers at which changes occurred. There has always been some conjecture that the optical formula of the lenases was also changed. I have correspondence with both Wetzlar and Solms that confirms that the actual optical design - apart from the coating modification - - didn't change throughout the production run, 1956-1970. Because your result with the numbers and this response might be interesting to LUG readers, this technologically challenged LUGGER is going to try to forward both. Best, Seth LaK 9 - -- To unsubscribe, see http://mejac.palo-alto.ca.us/leica-users/unsub.html