[LargeFormat] Compound Shutters

[Wilkes, Don MSER:EX]

Thanks, Richard!  I had a response from Mr Croell this morning, which =
echoes
much of what you just said.  Here it is:

-------------------
Don,

D.R.P. stands for Deutsches Reichspatent (not republic, unfortunately) =
and
was
superseded in West-Germany by the "Deutsches Bundespatent" DBP. By the =
way,
you
can research German and other patents online (search functions =
available in
English, too) at the German patent office: http://www.depatisnet.de. =
Both
DRP and DBP patents are listed under the DE prefix (pulldown menu top =
left
in the beginners search mask). I just checked your number DRP 142293, =
and
there must be
a typo since it is about some mechanical construction. However, it is =
from
1902
which was the year Rudolphs Tessar came out, so I assume its off by =
only a
few
numbers?

As for your lens, the "Lens Collectors Vademecum" says the following =
about
your
lens:

"Series IIb (1902) f6.3. 1.5-23.25in. It is suggested to use 14in. for =
10x8,
6in. for 5x4. This was a most favoured lens! 70=B0. .... The series =
numbering
suggests it replaced Anastigmat series II in the f6.3 series in the =
lists.
This
f6.3 Tessar is the connoisseurs choice and usually available.  In 1914 =
it
was
made in 3, 3.5, 4.75, 5.25, 6.0,6.5, 7.0,8.25, 10, 12, 14, 19.25, and
23.25inch,
and 14 in was suggested for 10x8, 6in for 5x4."

The Zeiss article there also mentions that serial number 1734xx was =
1912, so
yours is before that.

Arne Croell
-------------------

It looks like I shall have to peer more closely at that Patent number, =
and
make sure I have it right before rummaging around on that German Patent
website.

So, who says you have to have the latest and greatest =
computer-designed,
multi-coated hunk o' glass?  My pre-First-War little Tessar managed to =
give
some shots of Yosemite last September which pleased me, and that's all =
that
matters, right?

Cheers,
\donw


> -----Original Message-----
> From: largeformat-admin@f32.net [mailto:largeformat-admin@f32.net]On
> Behalf Of Richard Knoppow
> Sent: December 5, 2003 3:44 AM
> To: largeformat@f32.net
> Subject: Re: [LargeFormat] Compound Shutters
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> ----- Original Message -----=20
> From: "Wilkes, Don MSER:EX" <Don.Wilkes@gems9.gov.bc.ca>
> To: <largeformat@f32.net>
> Sent: Thursday, December 04, 2003 2:22 PM
> Subject: RE: [LargeFormat] Compound Shutters
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> >
> > >   Again, I don't have a starting date for D.R.P. but it
> was
> > > used until sometime after 1945. D.B.P. was adopted at
> the
> > > end of the war but was not immediately used so one finds
> > > equipment made as late as 1950 or so still marked DRP or
> >
> > Oh, it means German Republic *Patent*, then!  That would
> explain why I
> > couldn't find a reference to it either online or in one of
> the office
> > Almanacs... I should have realized this, as last July, I
> had a short note
> > from Mr. Arne Croell on my old Carl Zeiss Jena 165 f/6.3
> Tessar, which I was
> > trying to date.  It has an apparent serial number of
> 166752, and is marked
> > DRP 142293.  He said that he was travelling, and didn't
> have his list of
> > Zeiss numbers at hand.  However, he mentioned that list
> only starts in 1927,
> > at which point the serial #s were already past the million
> mark.
> >
> > So, it looks like DRP is pre-30s, at any rate.
> >
> > By the way, Mr. Croell had an article on VEB Carl Zeiss &
> Docter Optic
> > lenses in the July/Aug 2003 issue of View Camera, which is
> what prompted me
> > to write to him. If Mr. Croell is listening -- could you
> possibly tell me a
> > bit more about my lens, especially its likely date of
> manufacture?  I've
> > never found it mentioned in any references.
> >
> > Cheers!
> > \donw
> >
>   The earliest Zeiss serial number in McKeon's guide is
> 173418 from 1912.
>   DRP 142294 is the original Paul Rudolph patent on the
> Tessar, the equivalent of USP 721,240
>   This is one digit earlier, are you sure this is correct?
>   The German Patent Office was established in 1878. DRP and
> DRGM probably date from that time. They were in use until
> the end of the Deutches Reich in 1945 and the establishment
> of the Bund. The abbreviations DBP and DBGM were used after
> that although equipment made up to the early 1950's
> sometimes has the old abbreviations.
>   I found a site which allows searching German and other
> patents and has old patents on it, at least in the form of
> abstracts. This is http://www.depatisnet.de
>   A search for the patent above got a non optical patent for
> something. I don't have enough German to make out the claims
> and the drawing makes no sense whatever.  The Rudolph number
> comes up with the Tessar patent. I don't think one can
> search for design patents on this site. There is another
> site which might allow such searches but its all in German.
> ---
> Richard Knoppow
> Los Angeles, CA, USA
> dickburk@ix.netcom.com
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