Archived posting to the Leica Users Group, 2002/03/24

[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]

Subject: RE: [Leica] A Tonne?
From: "Frank Filippone" <red735i@earthlink.net>
Date: Sun, 24 Mar 2002 14:12:42 -0800

Europeons use the comma instead of the decimal point in numbers.  At least
it is a common thing to see.  Suggest 10,000 metric Tonnes is really 10.000
Tonnes  , which is 10,000 KG or 22,000 pounds of glass.  This is more
consistent with the making of 10,000 -30,000 lenses per year.....rather than
1000 times that amount.
The Math:
Figure a lens is half glass, half metal.  Average of say 300g ( 3/4 of a
pound of lens) .... then this becomes 3/8 pound of glass per lens.  Say they
grind off 1/3 of the glass.  That would say the gross amount of glass per
lens is 5/11 of a pound ... times 11,000 lenses ( make the math easy) is
5,000 pounds of glass per 10,000 lenses...


Using that number, and figuring 30,000 lenses per year ( assume this to be
correct as we do have some lens quantity figures) and you get 15,000 pounds
of glass.....Looks about right for the quantity of glass they claim to
consume in a year... 10 Metric Tonnes.

BTW< we have nothing in here about binoculars, that could be much more then
photographic lens volumes......

Interesting figures, absolutely useless information unless you are int he
glass supply business!

Frank Filippone
red735i@earthlink.net

- --
To unsubscribe, see http://mejac.palo-alto.ca.us/leica-users/unsub.html

Replies: Reply from Henning Wulff <henningw@archiphoto.com> (RE: [Leica] A Tonne?)