Archived posting to the Leica Users Group, 2009/10/08
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]That rather misses the point though Richard. To assist in achieving those design goals, some of those blanks are from extremely expensive and exotic glass types. Grinding and inspection is done one element at a time by extremely skilled operators. Assembly into the intricate all metal mounts is entirely by hand which themselves are expensive and made to tolerances of 1/100th of a mm. Example of important contributor to Leica lens excellence http://gallery.leica-users.org/v/gh/g/l_001/s032.jpg.html http://gallery.leica-users.org/v/gh/g/l_001/S07.jpg.html http://gallery.leica-users.org/v/gh/g/l_001/S09.jpg.html 2009/10/9 Richard Man <richard.lists at gmail.com> > That may be true, but I am betting dollars to donuts that the cost of > blank does not account for the difference in end prices. > > The low number manufactured is the prime reason, and because of that, > they can afford to use high level of tolerance and greater emphasize > on certain design goals (i.e. good performance even wide open), but > those are "side-effects." The main cause is still the simple > arithmetic of "they ain't going to sell many" > > On Thu, Oct 8, 2009 at 11:26 AM, Doug Herr <wildlightphoto at > earthlink.net> > wrote: > > > > Company A can specify glass type ABC with tolerances for refractive index > +-0.2% dispersion +-0.25% surface hardness +-0.3% expansion coefficient > +-0.7% and company B can specify the same glass type with tolerances 1/2 of > company A's requirements and I'll bet company B's glass blanks are gonna > cost more and the finished lenses will show a lot less sample variation. > > > > > > > > -- > // richard m: richard @imagecraft.com > // w: http://www.imagecraft.com/pub/Portfolio09/ blog: > http://rfman.wordpress.com > // book: http://www.blurb.com/bookstore/detail/745963 > > _______________________________________________ > Leica Users Group. > See http://leica-users.org/mailman/listinfo/lug for more information > -- Cheers Geoff The new LEICA M9 Passion for perfect pictures. http://www.m.leica-camera.com http://gallery.leica-users.org/v/gh/ http://www.pbase.com/hoppyman