Archived posting to the Leica Users Group, 1996/09/11
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Daniel Cardish wrote: > > Has anyone compared the earlier 35mm Aspherical Summilux with the current > ASPH Summilux? (If you've seen this question from me more than once I > apoligize; The mail keeps getting returned to me). > > Dan Cardish > <dcardish@spherenet.com> > > <http://www.spherenet.com/dcardish/photo.htm> > Hi Daniel, Roger here from Kindermann. How are things at the P.M.'s office? The main difference between the two versions of the 35 Summilux ASPH is the process used to produce the aspherical element. The new one is produced with a new method called "Precision blank moulding" in which raw glass is heated and then pressed into the aspherical form. This is a new computer-controlled process, not to be confused with ordinary bank-moulding which only fulfills low quality demands. This new automated process is much less problematic than the old "grinding and polishing" technique as it eliminates the grooves than can result with manual grinding and polishing. Some manufacturers fill in these grooves with synthetic materials, an option which is of course unacceptable to Leica. This is why they have employed this new high-tech process. Cheers!