[LargeFormat] wollensak lens color coded dots

[Richard Knoppow]

----- Original Message ----- 
From: "Georges Giralt" <georges.giralt@free.fr>
To: <largeformat@f32.net>
Sent: Saturday, December 06, 2003 12:48 PM
Subject: Re: [LargeFormat] wollensak lens color coded dots


> Hi !
> I've worked a while in a automotive parts company.
> The test machine at the end of the manufacturing process
put a pair of
> colored dots on the equiment to state the range of values
found upon
> testing.
> This may explain the varieties of colors on your lenses
;-)
>
> LNphoto a écrit :
> > Okay  who can tell me what the dots mean on coated
Wolley lenses.   One
> > dot is yellow, I think one is either red or blue.  Some
lenses have two
> > dots.  Does this mean Wolley was "multi-coating" lenses
20 years before
> > the Japanese "invented" the process?
> >
> > Les
  I think the dots must be inspection dots. My Tele-Optar
has a yellow dot on it. I've heard cleams that this means it
should be used with a yellow filter but the lens seems to be
well achromatized so I don't think this is true. In fact,
its a very good lens.
  B&L lenses sometimes have two or thee dots on them
suggesting they are inspection stamps of some sort but
that's a guess.
  Wollensak lenses made after about 1946 were coated and
have the C-W trademark for "Wocoated" on them. This seems to
be in a sort of lavender colored ink, perhaps to mimic the
color of the coating. When hard coatings were introduced
about this time several lens makers put markings of some
sort on their lenes to indicate coating. Kodak's was a
circle-L for "Luminized", Schneider's was a triangle,
briefly white then red. After coatings became routine these
special symbols pretty much disappeared.
  I've asked a friend in the optical business if he knows. I
will pass along whatever I learn. Unfortunately, both
Wollensak and B&L exist only as trademarks operated by
people who have no knowledge or interest in the history of
the companies.

---
Richard Knoppow
Los Angeles, CA, USA
dickburk@ix.netcom.com