[Leica] New 75 Summilux

["Frank Filippone" <red735i@worldnet.att.net>]

"The new lens is made in Germany.  The
weight has been reduced by 40g, from 600g to 560g.  

My guess is that the wieght reduction has come about through using
different glass from
the previous version.  The previous version used what Leica called
"Noctilux"
glass.  

Since Leica sold off the former Leitz research lab which produced the
Noctilux glass, perhaps this is why the 75 has been revised.  Or it could
be
the elimination of high lead content glass previously used.  

Bill Rosauer "

There are some statement in this theory that need challenge...

It is a bit "strong" to state that Leica reduced the weight of the lens by
channging the glass.... this requires major optical design, test, and
production effort.  It is far more likely that the weight reduction came as
a result of materials change to the barrel components.... like switching
from brass to aluminum (sp?) ....or some form of exotic "plastic"...
similar to the weight differences in the current chrome or black lenses. 
This is a simple change that also would accomodate a change of suppliers of
the barrel components as the lens production changed from Canada to
Germany.  Major Optical changes are very unlikely.  BTW, 40 grams  , if
they did the redesign, is about 1.4 ounces.....that is a lot of glass!

Second: I am fairly confident that the ELCAN facility, bought by Hughes,
then again by Raytheon, in the recent past, did not make any glass from
scratch.  They employed glass in their optical designs as made by other
companies.  We have a present or former ELCAN employee on this list, he may
be able to answer with some authority.

Let's go easy on lens redesigns, it takes a lot of effort that is best
spent with developing totally new designs.


Thank You
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Frank Filippone
red735i@worldnet.att.net