[LargeFormat] Roman numerals on Zeiss barrel lenses

[Richard Knoppow]

----- Original Message ----- 
From: "Les Newcomer" <LNPhoto@twmi.rr.com>
To: "f32" <largeformat@f32.net>
Sent: Tuesday, June 24, 2003 7:21 PM
Subject: [LargeFormat] Roman numerals on Zeiss barrel lenses


> http://home.twmi.rr.com/lnphoto/zeissbarrel.jpg
>
> The above link shows two  Zeiss lenses,  the top is a 25cm
Tessar with
> the Roman numeral "X" and in subscript "2"
>
> The lower lens is a Protar VIIa  with the roman numeral
"IV" and in
> subscript  "1"
>
> The owner of the Tessar also owns  two other lenses all
marked "Ic"  so
> I assume they are Tessars.
>
> He has an 18cm  marked  BVI  (sub 2)   and  a 21 Marked
VII (no sub)
>
> Any ideas what these alien markings mean?
>
> the only pattern I see is that the roman numerals increase
in size as
> the barrel dia increases.
>
> My Protar, at f7.7 is the smalles and is marked #4
> The 18cm  f4.5 is marked #6  with an odd B in there
> The 21 cm  also 4.5 has to be larger than the 180 and is
marked VII
> and the 25cm is marked "10"
>
> Not sure if there really were three different sizes of
barrels between
> a 210 and a 250mm, but it's a theory.
>

  I don't know what the X2 means.
  1c is a series number both Zeiss and Bausch & Lomb made
Tessars with series numbers. Series 1c is the f/4.5 version;
Series 2b is the f/6.3 version.
  Protar lenses came in several series.
Series I  = f/4.5, original design
Series II = f/6.3  "
Series III= f/7.2
Series IIIa = f/9
Series IV = f/12.5 medium wide angle
Series V = f/18 extreme wide angle
Series VII = f/12.5 Single cells of convertible Protars
Series VIIa = f/6.3, f/7, f/7.7 Combined convertible
Protars.
  Protars and Tessars also had catalogue numbers. Some
lenses show these and some don't. They are NOT the numbers
on the sides of the barrel.
  I have a feeling these were added by some owner and not
Zeiss.
  FWIW the No.4 Series VII Protar is 35cm or 14 inches FL.
Some of these numbers have an a or b subscript. The numbers
for the Series 1c and 2b Tessars do not overlap. Series 1c
(f/4.5) run from No.10, at 4cm to No.20 at 50cm (must be
huge).
  The 2b (f/6.3) runs from No.0 at 4cm to No.11 at 60cm.
  This is all from a 1926 catalogue and 1928 price list.
There may have been other numbers or series at other times.
In general, B&L follows approximately Zeiss practice but the
focal lengths of the various lenses are somewhat different.

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

  I don't have a listing for the Series VI but I think it
may have been the "Triple Protar" a Dagor type but with
reversed order of powers of the cemented elements.
  Paul Rudolf was working on this design at the time the
Dagor was patented by von Hoegh. I suspect this is why Zeiss
refused to hire von Hoegh when he applied there before going
to Goerz.