[LargeFormat] Wollensak Extreme Wide Angle Lenses

[Richard Knoppow]

----- Original Message -----
From: "Clive Warren" <Clive.Warren@megacycle.co.uk>
To: <largeformat@f32.net>
Sent: Monday, April 21, 2003 5:21 AM
Subject: Re: [LargeFormat] Wollensak Extreme Wide Angle
Lenses


> At 04:49 21/04/2003 -0700, Richard Knoppow wrote:
>
> >-------Original Message-------
> >From: Clive Warren <Clive.Warren@megacycle.co.uk>
> snip
>
> >>Looking at the 5x7 version (marked Wollensak 5x7 Series
IIIa EX.W.A
> >>f12.5  4 5/16") of your 8x10 Wolly lens this does indeed
have two elements
> >>in each lens group.
> >>
> >>I would assume that the f12.5 version has better
contrast than the f9.5
> >>version if only because there are fewer lens elements in
the f12.5 version
> >>
> >>and both lenses are uncoated. I seem to recall seeing a
version in an
> >>alphax shutter that was coated and I think this was the
f9.5 version.
> >>
> >>Cheers,
> >>             Clive
> >
> >
> >   The f/9.5 W.A. Velostigmat is a unique design. It
appears to be a
> > compounded double gauss with each of the four components
consisting of
> > two cemented elements. At a guess, this was done to
obtain the
> > performance of some glass types which were not
available, but I have no
> > actual information on this lens.
> >   The four cemented surfaces must have made them
expensive lenses to
> > make. I've never had one so have no idea of how good (or
bad) they are.
> >   A number of other WA lenses are essentially double
Gauss types. The
> > Kodak Wide Field Ektar, for example. The Bausch & Lomb
Metrogon and Zeiss
> > Topogon can be seen as also derived from the double
Gause type.
> >   It seems that a number of lens makers copied the Zeiss
wide angle
> > Protar types. They are surprizingly good lenses although
modern WA types
> > are clearly much better than any of the pre-WW-2 WA
lenses.
> >
> >Richard Knoppow
> >dickburk@ix.netcom.com
> >Los Angeles, CA, USA
>
> Richard, thank you for the info. I had always wondered
about the
> construction of the f9.5 lens. Given that each group has
the same number of
> glass to air surfaces as the protar design f12.5 then
contrast may well be
> about the same with both lenses.
>
> I have had the f9.5 version for a few years but only very
recently found
> the time to give the shutter a CLA which it badly needed
as there was only
> one speed available! I have yet to mount it on a lensboard
for use with the
> 8x10. One of the main reasons for this lack of use is that
I tend to use
> one of my favorite lenses for 8x10 extreme wide angle
work, the B&L Zeiss
> 8x10 183mm protar f18 Series V - now that is a real
challenge to use unless
> it is a bright sunny day. When I get some spare time will
try out the Wolly
> lens and post some comparison shots on the f32.net Forum.
>
> My experience with the similar designed double Gause type
Wide Field Ektars
> is all good and they handle colour very well indeed. Here
is an example
> shot taken with the135mm WF Ektar:
>
http://www.f32.net/cgi-local/discus/show.cgi?tpc=6&post=323#
POST323
>
> It remains to be seen how well the f9.5 Wolly would handle
colour. I shoot
> B&W exclusively in 8x10 so unless I win the lottery colour
is a long way off.
>
> The 135mm WF Ektar has a permanent place in the 4x5 kit
bag. Steve Grimes
> sent me a new flange for the 250mm WF Ektar recently so I
am looking
> forward to using that on 8x10 when additional lens boards
are resourced.
> The example of the lens sitting here was bought from Kodak
and was used to
> make some of the huge Coloramas that Kodak used to
advertise their products
> in Grand Central Station many years ago.
>
> Cheers,
>             Clive
>
>
  The f/9.5 lens I am familiar with has eight glass-air
surfaces, double the number of the WA Protar. The f/12.5 is
probably a version of the Zeiss Series IV Medium Wide Angle
Protar. Both Zeiss and B&L built these. The more common one
is the Series V Exreme Wide Angle Protar, f/18. The Series
IV coverage is around 80 degrees, the Series V about 100
degrees. Wollensak may have used better glass than the
original Zeiss and B&L designs and may therefore have had
wider coverage.
  The WA Protars are derived from Paul Rudolph's original
Protar design and consist of two cells each with two
cemented elements. The Protar was the first lens to use the
then new "Jena" glass from Schott glass.
  Rudolph later derived his Tessar from this design by air
spacing the front component.
  WA Protars are pretty good lenses but more modern lenses
are considerablly better corrected. Their main virtue is
small size and light weight.
---
Richard Knoppow
Los Angeles, CA, USA
dickburk@ix.netcom.com