Archived posting to the Leica Users Group, 1999/09/14
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]>Date: Mon, 13 Sep 1999 19:49:00 >From: Art Sala <artsala@earthlink.net> >Subject: Re[2]: [Leica] Plastic Aspheric Lens Elements >Ken: > >I heard that Zeiss is the only lens manufacturer that has the ability >to grind glass aspheric elements. Then again, I don't know if it matters >(photographically speaking) whether the aspheric element is ground glass, >moulded plastic or some sandwiched hybrid. Maybe some other lug lens >guru can give more technical insight. > >Cheers, Arturo >From: "Ken Iisaka" <kiisaka@ibm.net> >To: Internet Mail::[<leica-users@mejac.palo-alto.ca.us>] > >Subject: Re: [Leica] Plastic Aspheric Lens Elements >Date: 9/12/99 8:47 PM > >The Noct-Nikkor was indeed hand ground. The one and only guy who was >responsible for making the aspherical front element retired years ago, >and >the production ceased several years ago. It is still listed on Nikon >USA's >catalogue, but it was taken out of the Nikon Japan catalogue about a couple= > >of years ago. > >Several Japanese publications such as Asahi Camera have stated that Hoya >supplies moulded aspherical elements to Leica. > >> Leica uses glass in its ASPH lenses. They *may* use plastic in their >> 'lower' priced Japanese made zooms, though I am not sure of this. Nikon >> certainly uses plastic resin elements in some of its aspherica zooms. > I >> suspect that their 50/1.2 Nocti uses glass. Not sure about Canon or >Zeiss. >> I think you can tell by the relative price. Plastic aspheric elements >are >> designed to produce decent optics at lower prices. Many of the aspheric >> zooms offered by sigma and other 3rd party lens manufacturers employ >> plastic elements. > >- --=PMail:=_0000@@uCV5Ob00sdmDdkxmQawU-- > ###############: In the well-known photographic review Leica foto (n°7/97, pp.26-9, french edition)there is an interesting paper on the Leica asph lenses : 1°) There are no plastic asph element in the Leica lenses, even in the "japanese" lenses (4/35-70). 2°) The Leica technology is a "polishing" (? "polissage" in french) by CNC.There is a picture of the machine :i read "SLP-100 made by Schneider". 3°) Zeiss(op.cit., p.28) was the first to develop an hybrid technology : an "plastic" asph element put on a spherical element. Dominique Pellissier