Archived posting to the Leica Users Group, 1996/09/16
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Here the real story, straight from the factory. The six lens elements of the Summicron are individually produced. Every lens element has a slight deviation from the norm. Leica uses computer controlled analysis to match the plus and minus tolerances of every lens element when assembling the lens. Due to the optical and mathematical properties of every individual lenselement any combination gives one of three exact focal lengths. These are 50,00 and 51,9 and 52,2. No other focal length is possible. Any Summicron can then have as engravings '00', '19' and '22'. (My Noctilux btw has '00'.) The 135mm of course has the same story: here the values are engraving '50'-----> exact 135,00mm engraving '45'-----> exact 134,50mm engraving '55'-----> exact 135,50mm The 90mm '00'-----> 90.00mm '95'-----> 89,50mm '05'-----> 90,50mm Greetings Erwin Puts