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 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