RE: [Leica] Re: glass or plastic

["Kotsinadelis, Peter (Peter)" <peterk@lucent.com>]

Thanks Alan,

I am not sure which lenses use the plastic aspheric elements either, perhaps
its the TV Camera or Copier lenses they make?  I had an older Tokina once
that has a rear plastic aspheric element.  The problem with plastic lens
elements is that when left in the sun for an extended period of time, it can
cause the lens to change shape.  Needless to say, I soon got rid of the
Tokina and went back to all glass lenses.

Peter K

- -----Original Message-----
From: Alan Ball [mailto:AlanBall@csi.com]
Sent: Wednesday, January 27, 1999 10:24 AM
To: leica-users@mejac.palo-alto.ca.us
Subject: Re: [Leica] Re: glass or plastic


Peter,

I feel really weird doing this but I'll defend Eric's argument, since he
is away for a few days ;-)

From Canon lens FAQ (I already posted this a few days ago):
QUOTE
"Depending on the purpose, Canon now uses 4 different aspherical lenses
in its products: 
(1) a ground aspherical lens;
(2) a glass-mold aspherical lens;
(3) a high-precision, plastic-mold aspherical lens; and 
(4) an ultraviolet cure resin-coated replica lens. 
Among them, the wide-bore, ground aspherical lens is employed in the L
lens series for performance improvement. "
UNQUOTE

So, this time he was right... (dunno which lenses use the plastic
elements though)

Please do not hold this against me  ;-)

Alan

Kotsinadelis, Peter (Peter) wrote:
> 
> Eric,
> 
> Your wrong about Canon and their lenses. They use all glass aspheric
> elements in their lenses.
> 
> Here are clips from their Press Releases to confirm this (did my homework
> this time).
> 
> Canon ELPH:
> .....ultra-sharp 24-48mm all -glass aspheric lens;
> 
> Canon EF 28-135 f/3.5-5.6 IS USM zoom lens:
> 
> Optical construction of the lens includes the use of a glass-molded
aspheric
> element for high image quality.
> 
> Peter K
> 
> -----Original Message-----
> From: Eric Welch [mailto:ewelch@ponyexpress.net]
> Sent: Sunday, January 24, 1999 6:44 PM
> To: leica-users@mejac.palo-alto.ca.us
> Subject: Re: [Leica] Re: glass or plastic
> 
> >Can anyone else comment on whether or not the ASPH element in the
> >latest 35/1.4 is plastic or glass (or did I misinterpret the post)?
> 
> I've never heard it was glass. I don't think it is.
> 
> And do know Canon uses a hybrid Aspheric element that is part glass part
> plastic in some of its consumer lenses.
> 
> Eric Welch
> St. Joseph, MO
> http://www.ponyexpress.net/~ewelch
> 
> Canadian DOS prompt: EH?\>