Archived posting to the Leica Users Group, 2007/08/20
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]The "aspherical" was made in small numbers. It has 2 aspherical elements which had to be ground by hand to a profile which deviated from spherical by a tiny amount. The scrap rate of these hand made elements was reported to be high and far fewer are thought to be made than the 2000 which had been planned. The "ashp" was a new design using one aspherical element manufactured by a hot pressing process where a super accurate aspherically surfaced die is pressed against the heated glass imprinting the aspherical profile onto it. This is a MUCH less expensive process and allowed the lens to go into normal production. Several other lenses were subsequently updated to include hot pressed aspherical elements. The size of the elements which can be produced by this process is limited, I don't know whether by stress or load levels or accuracy. This limits its use mainly to the smaller diameter elements in wide angle and zoom lenses. Nowadays grinding aspherical elements using CNC machines is feasible so it is not such an expensive process any more. AFAIK the only current Leica lens using a ground aspherical element is the 90mm f2 - someone will surely correct me if I am mistaken. The original Noctilux, an f1.2 design, also used 2 hand ground aspherical elements and was made in tiny quantities also. I own a 35mm aspherical and it is the finest lens I have ever used. It was the main reason I bought an Epson RD1 and then a M8! Frank On 20 Aug, 2007, at 11:43, bernardo feio wrote: > Hello > > I will bookmark the link this time! :-) > > Thanks > > Any optical difference between the 35mm Summilux "Aspherical" and > the ASPH? > > > Didier Ludwig <leica@screengang.com> escreveu: opps sorry have > mixed up summicrons and summilux. Colucci indicates the value for a > asph lux 35 with $2.2k which is realistic. > > >> The prices for used 35 asph Summilux have increased compared to >> Colucci's list, since the introduction of the Epson R-D1 and the >> M8. Uncoded samples sell for $1600-2000, coded for more. >> D. >> >> >> >>> Summilux 35mm (ASPH and before) > > > > > _______________________________________________ > Leica Users Group. > See http://leica-users.org/mailman/listinfo/lug for more information > > > Flickr agora em portugu?s. Voc? clica, todo mundo v?. Saiba > mais. > > _______________________________________________ > Leica Users Group. > See http://leica-users.org/mailman/listinfo/lug for more information