By Arne
Croell © 2002
Following is
a slightly revised version of the table on Docter Optic LF lenses that I posted
in 1998 plus some additional information on the company history. It is based on
a Docter Optic company brochure from
1993 and individual leaflets on the lenses from 1994, plus additional
information that was sent to me from users of these lenses, and from articles
and web sites. I would like to thank everybody who contributed
information. I also added three tables
on Carl-Zeiss Jena LF lenses manufactured between WWII and 1991, as well as
post-WWII Czech (Meopta), and Russian LF lenses.
Disclaimer:
I am relying on printed literature, information from the internet, and other
secondary information sources. In addition to possible errors in my sources, I
may also have introduced new ones, so please use this text and tables only for
preliminary information and countercheck anything important for you. I would like to add that I have never been
associated in any way with Docter or with Zeiss or any other company mentioned
in this article. My personal experience is limited to a Docter Apo-Germinar
300mm f/9.
Docter
Optic was originally a small West-German company founded in 1985 by Bernhard
Docter (hence the company name – no relation to academic titles). Note the
spelling of the name: Docter, not Doktor, Doctor, or Doctar - the latter
is one of their lens names; and Optic written with a “c”. They made OEM
projection optics, lighting optics, car headlight optics, etc. Their specialty
was a glass blank molding process for aspherical optical elements. They were
located near Wetzlar. The company expanded, and in 1989 bought an Austrian
subsidiary, which had originally been the optics department of Eumig, an
Austrian manufacturer of home movie projectors.
After the
German reunification in 1990 the East German Carl Zeiss Jena combine, which was
quite big (70,000 employees), and made everything from binoculars to
microelectronics in the GDR, was downsized and separated into different parts.
The West-German Carl Zeiss company only
took back a small core part (no, not the photography related business unit
– the microscope division). Another
part formed the new company Jenoptik,
now successfully working in clean room technology and photonics. Other company
divisions were sold off or finally closed down.
The Docter
Optic group bought some of the plants of
the former Carl Zeiss Jena combine in 1991. In August 1991, Docter
acquired the plant in Saalfeld,
Thuringia, which had made the Carl Zeiss Jena large format optics in the GDR,
and was still producing them then. He also bought another former Zeiss plant
making binoculars in nearby Eisfeld at the same time. The Saalfeld plant was
originally founded in 1911 as Optische Anstalt Saalfeld (OAS) and produced
optical parts (prisms, lenses) and some objectives for Zeiss before and during
WWII. During GDR times they made all photographic, movie, video, projection,
and process lenses for Carl Zeiss Jena, as well as a variety of other optical,
electronical, and medical components.
In 1995
Bernhard Docter died and the Docter group went bankrupt. The main parts of the
group were eventually sold to a holding owned by Rodenstock, Hella,
and Bosch (the latter two
being – among many other things - car
part manufacturers; their interest was probably related to the car headlight
optics part of Docter).
Remark: the
Rodenstock share of that holding is still held by Rodenstock itself, and not
by Linos, the company
that recently acquired the Rodenstock
Präzisionsoptik subsidiary (they produce the Rodenstock LF optics) from
Rodenstock.
The present
Docter company does no longer manufacture view camera optics, but they still
make projection optics, OEM optics, and blank molded aspherics. They have
recently relocated to Neustadt/Orla in Thuringia. They have a website at http://www.docteroptics.com/. The plant
in Saalfeld is now abandoned and the buildings are offered for rent (as of May
2002).
To add some
confusion, the binocular manufacturing plant in Eisfeld was sold in 1997 to a
different company, “analytik jena”,
but also uses the name Docter (http://www.docter-germany.com/index1.htm).
Docter
Optic LF lenses
From 1991
to 1995, Docter Optics continued the GDR Carl Zeiss Jena (CZJ) lines of large
format optics (Tessar, Apo-Germinar) under the Docter name, and started
bringing out new lenses (the 65mm Doctar WA wideangle lens) shortly before the
bankruptcy. After the bankruptcy or at the latest after the sale to the
Rodenstock/Bosch/Hella consortium they stopped producing LF lenses. In 1997
Docter offered their remaining inventory of large format lenses on their web
site (removed in early 1998), mainly for wholesale. Badger Graphic had some of those
lenses for a little while, but they are long gone. As of July 2002, Mr.
Cad in Croydon, UK, still has a few new Docter lenses listed (check under
“Doctar”).
All Docter
LF lenses, except the 65mm Doctar WA, were originally designed by and for Carl
Zeiss Jena, and older ones are marked that way. If there is any difference
between the Docter Optic lenses and late GDR-made ones it is probably the
coating quality - the 1993 Docter brochure mentions the installation of new
coating facilities in Saalfeld. However, there is no mentioning that Docter LF
lenses were ever multicoated. Until there is evidence to the contrary, I would
assume they are single coated. The Apo-Germinars I have seen were single
coated. I am not sure if the lenses were ever sold with shutters during GDR
times, or if the GDR ever made leaf shutters at all. They were originally
designed (in the GDR) for use with a shutter behind the lens (a "Grundner" type shutter,
somewhat similar to a Packard shutter) in studio cameras like the Pentacon
“Globica“. Thus Docter offered all the lenses (except the 65mm) both in barrel
mount and adapted to Copal shutters. For this reason, the long focal length
have two different maximum apertures, depending on the mount. Note that sizes,
weight, and filter threads are often different for barrel and Copal
versions!
Apparently,
CZJ made process and LF lenses that had been discontinued when Docter Optics took
over, but carry the Apo-Germinar or Tessar designation; so if something is not
listed in the table it doesn’t mean it never existed! I have added a second
list with those CZJ post-WWII lenses I am aware of.
There were
four different lines of lenses from
Docter Optics:
Tessar/Doctar
These are
direct descendants of Paul Rudolphs Tessar from 1902, with 4 elements in 3
groups. Note that the first years after Docter Optic acquired the plant (1991),
they were sold as Docter-Optic Tessar, later the name was (had to be?)
changed to Doctar. They came in focal lengths from 50mm to 360mm, with a
maximum opening of f/4.5, except for the 300mm and 360mm in Copal 3, which are
limited to f/5.6 and f/6.8 by the shutter. With 53° - 55° coverage, the short
focal lengths (50mm, 75mm, and 105mm) obviously don’t cover 4x5 or larger, but
I’ve listed them anyway. Because of the large opening the longer focal length
are rather big and heavy, and only the 135mm comes in a Copal 1 shutter (the
longer ones all have a Copal 3). According to Docter the optimum aperture is
f/22. Docter/CZJ sold Tessars also as enlarging lenses. I have added these at
the bottom of the table. One would expect them to perform similar to other
Tessar-type enlarging lenses, like Rodenstocks Rogonar-S or Schneiders
Componar-S. Note that in the original Docter literature there is a problem with
the numbers for the image circle. They frequently differ from what one gets
using their quoted angle of coverage with the equation
d =
2 · a · arctan(j/2)
(d= image
circle diameter; j= angle of coverage; a= distance of back nodal point of lens to film,
equals focal length at infinity).
This is
compounded by the fact that they never stated in the original tables whether
the angles or circles where for optimum aperture (f/22) or wide open. In this
version of the table I added the ones calculated from the angle of coverage if
the Docter ones seem to be too optimistic and list the Docter ones in brackets.
Apo-Germinar
These are
classic process lenses of the "Dialyte" or “Celor” type, 45-46°
coverage, similar to Apo-Artars or Apo-Ronars. Symmetric construction, 4
elements in 4 groups (up to 450mm), or 6 lenses for the 600, 750, and 1000mm
versions. Maximum aperture f/9, except in the long focal lengths (600mm, 750mm,
1000mm) in Copal 3. The optimum aperture is f/22. As process lenses they are
optimized for 1:1 reproduction ration, but it is well known that this lens type
holds up quite well when used at infinity (within its image circle). Around
1994/1995, Docter Optic introduced an improvement of the Apo-Germinar, a
version with an additional removable brass ring spacer/washer
("Trimmring" in German) between the front cell and the shutter. It is
intended to optimize the performance at the edges of the field at magnifications
smaller than 1:5 (up to infinity) by changing the cell spacing. For
magnifications between 5:1 and 1:5 the ring is omitted, for all other
magnifications it is used. There was a test report (with the 450mm version)
about this in the No. 5 (Sept./Oct.) issue of the German magazine Photo Technik
International from 1995, p. 32-33.
Being
process lenses, the image circles given in the table are for 1:1. The image
circle diameter at infinity is about half that value.
Symmetric
wide angle process lenses, with 63-73° coverage, 8 lenses in 8 groups. I
haven’t seen this construction anywhere else, but I am not an expert for
process lenses. The optimum aperture is f/16 according to the Docter
literature. No idea how they perform at infinity. Again, the image circles are
for 1:1 reproduction ratio and the image circle diameter at infinity is about
half that value.
Only one
focal length of this type was ever in production, the f/4.5 65mm Doctar WA. It
was a new development and was introduced in 1993-1994; it is a
Biogon/Super-Angulon-type wide angle with 105° coverage, 8 elements in 4
groups. Note that it uses a Copal 1 shutter, whereas 65mm offerings from the
big four (Schneider, Rodenstock, Fuji, Nikon) all use Copal 0; the filter size
of 85mm is also rather large. Optimum aperture is f/22.
Notes
about the table:
a at 1:1 reproduction ratio
b calculated or estimated value
c there was either contradictory information
(general brochure vs. individual leaflet) and I chose the one more reasonable
(to me), or there were obvious typos that I corrected.
[]
information in brackets is from the original Docter literature, but may be
wrong.
? missing
information.
+ after the
smallest aperture means that it can be stopped down further, but there are no
markings.
|
Lens name |
Lens elements/ groups |
focal length[mm] |
max./min. aperture |
coverage[°] |
image circle diameter [mm] |
shutter |
filter size |
length/max. diameter[mm] |
weight[g] |
Remarks |
|
Doctar WA |
8/4 |
65 |
4.5/45 |
105 |
170 |
Copal 1 |
M85x1.0 |
92.8/90 |
? |
|
|
Tessar/Doctar |
4/3 |
50 |
4.5/? |
53 |
50b [55] |
Barrel |
M25.5x0.5 |
24.8/44 |
80 |
|
|
Copal 0 |
M30.5x0.5 |
24.0/61 |
? |
|
||||||
|
Tessar/Doctar |
4/3 |
75 |
4.5/? |
55 |
78 b [85] |
Barrel |
M25.5x0.5 |
25.7/44 |
80 |
|
|
Copal 0 |
M30.5x0.5 |
27.0/61 |
? |
|
||||||
|
Tessar/Doctar |
4/3 |
105 |
4.5/? |
55 |
109 b [130] |
Barrel |
M35.5x0.5 |
32.5/52 |
110 |
|
|
Copal 0 |
M30.5x0.5 |
29.8/61 |
? |
|
||||||
|
Tessar/Doctar |
4/3 |
135 |
4.5/? |
57 |
147 b [160] |
Barrel |
M40.5x0.5 |
34.0/62 |
160 |
|
|
Copal 1 |
M40.5x0.5 |
32.0/70 |
? |
|
||||||
|
Tessar/Doctar |
4/3 |
180 |
4.5/? |
55 |
187 b [220] |
Barrel |
M58x0.75 |
50.0/72 |
390 |
|
|
Copal 3 |
M49x0.75c |
47.0/102 |
? |
|
||||||
|
Tessar/Doctar |
4/3 |
210 |
4.5/? |
55 |
219 b [250] |
Barrel |
M67x0.75 |
56.8/84 |
490 |
|
|
Copal 3 |
M58x0.75 |
53.5/102 |
? |
|
||||||
|
Tessar/Doctar |
4/3 |
250 |
4.5/? |
55 |
260 b [300] |
Barrel |
M77x0.75 |
66.0/98 |
690 |
|
|
Copal 3 |
M67x0.75 |
63.0/102 |
? |
|
||||||
|
Tessar/Doctar |
4/3 |
300 |
4.5/? |
55 |
312 b [360] |
Barrel |
M95x1 |
85.0/121 |
1270 |
|
|
5.6/? |
Copal 3 |
M77x0.75 |
72.5/102 |
? |
|
|||||
|
Tessar/Doctar |
4/3 |
360 |
4.5/? |
45c |
298 b [430] |
Barrel |
M105x1 |
97.5/145 |
1870 |
|
|
6.8/? |
Copal 3 |
M77x0.75 |
72.5/102 |
? |
|
|||||
|
Apo-Germinar W |
8/8 |
150 |
8.0/45 |
63 |
370a |
Barrel |
M67x0.75 |
75.5/63 |
? |
|
|
Copal 1 |
M58x0.75c |
76.5/78 |
? |
|
||||||
|
Apo-Germinar W |
8/8 |
210 |
8.0/45 |
68 |
565 a |
Barrel |
M86x1 |
95.0/90 |
? |
|
|
Copal 1 |
M77x0.75 |
96.0/80 |
? |
|
||||||
|
Apo-Germinar W |
8/8 |
240 |
8.0/45 |
72-73 |
710 a,b [728]
a |
Barrel |
M110x1 |
118.0/114 |
? |
|
|
Copal 3 |
M110x1 |
118.5/114 |
? |
|
||||||
|
Apo-Germinar |
4/4 |
240 |
9.0/? |
45-46 |
408 a,b [430] |
Barrel |
M49x0.75 |
38.0/52 |
320 |
|
|
Copal 1 |
M40.5x0.5c |
38.0/73 |
? |
|
||||||
|
Apo-Germinar |
4/4 |
300 |
9.0/90+ |
45-46 |
509 a,b [530] |
Barrel |
M49x0.75 |
45.0/52 |
320 |
|
|
Copal 1 |
M40.5x0.5 |
45.0/73 |
265 |
|
||||||
|
Apo-Germinar |
4/4 |
360 |
9.0/? |
45-46 |
611a,b [620] |
Barrel |
M67x0.75 |
52.5/70 |
1000 |
|
|
Copal 3 |
M49x0.75 |
52.5/102 |
? |
|
||||||
|
Apo-Germinar |
4/4 |
450 |
9.0/? |
45-46 |
750a |
Barrel |
M67x0.75 |
66.0/77.5 |
1200 |
|
|
Copal 3 |
M58x0.75 |
66.0/102.2 |
? |
|
||||||
|
Apo-Germinar |
6/6 |
600 |
9.0/? |
45-46 |
1019a,b [1040] |
Barrel |
M86x1 |
109.0/92 |
2350 |
|
|
11.5/? |
Copal 3 |
M77x0.75 |
109.0/102.2 |
? |
|
|||||
|
Apo-Germinar |
6/6 |
750 |
9.0/? |
45-46 |
1230a |
Barrel |
M105x1 |
134.5/115 |
3900 |
|
|
14.5/180 |
Copal 3 |
M95x1 |
134.5/102.2 |
? |
|
|||||
|
Apo-Germinar |
6/6 |
1000 |
12..0/? |
45-46 |
1590a |
Barrel |
M105x1 |
150.0/115 |
4500 |
|
|
19.5/? |
42 |
1535a,b |
Copal 3 |
M95x1 |
150.0/102.2 |
? |
|
|||
|
Tessar/Doctar |
4/3 |
50 |
4.5/22 |
43.5 |
50 |
M39 |
M30.5x0.5 |
28/42 |
? |
Enlarging lens |
|
Tessar/Doctar |
4/3 |
75 |
4.5/22 |
60 |
85 |
M39 |
M30.5x0.5 |
28/42 |
? |
Enlarging lens |
|
Tessar/Doctar |
4/3 |
105 |
4.5/22 |
55.6 |
105 |
M39 |
M30.5x0.5 |
30/42 |
? |
Enlarging lens |
|
Tessar/Doctar |
4/3 |
135 |
4.5/32 |
56.6 |
150 |
M39 |
M40.5x0.5 |
32.5/51 |
? |
Enlarging lens |
|
Tessar/Doctar |
4/3 |
165 |
4.5/32 |
56.3 |
180 |
M50x0.75 |
M49x0.75 |
41.5.0/71 |
? |
Enlarging lens |
|
Tessar/Doctar |
4/3 |
180 |
4.5/22 |
57.2 |
200 |
M55x0.75 |
M58x0.75 |
49.8/64 |
? |
Enlarging lens |
|
Tessar/Doctar |
4/3 |
210 |
4.5/32 |
55.5 |
222 |
M52x0.75 |
M67x0.75 |
56.8/74 |
? |
Enlarging lens |
|
Tessar/Doctar |
4/3 |
250 |
4.5/32 |
52.2 |
247 |
M72x1 |
M77x0.75 |
66.5/85 |
? |
Enlarging lens |
|
Tessar/Doctar |
4/3 |
300 |
4.5/32 |
53 |
300 |
M90x1 |
M95x1 |
85/107 |
? |
Enlarging lens |
|
Tessar/Doctar |
4/3 |
360 |
4.5/45 |
45.1 |
300 |
M90x1 |
M95x1 |
88.8/115 |
? |
Enlarging lens |
Carl
Zeiss Jena/Jenoptik LF lenses
Additional
large format or process lenses (post WWII) by Carl Zeiss Jena/Jenoptik, discontinued
some time before 1991. Most of those lenses came in barrel. All of the barrel
lenses listed in the Docter Optic table above can also be found under the
Jenoptik or Carl Zeiss Jena label if manufactured before 1991/1992, but are not
listed again. Apparently, CZJ had both Apo-Germinars and Apo-Tessars as process
lenses for a while. The Apo-Tessars are built like regular Tessars (4 lenses/3
groups), but have less coverage (43°). The (non-Apo) Germinar-W appears to be a
Plasmat design. Information sources were internet web posts and usenet posts
from the Google
large format group list (formerly DejaNews), most of them from tables
posted by Michael Gudzinowicz, and
sale ads.
|
Lens name |
Lens elements/ groups |
focal length[mm] |
max./min. aperture |
coverage[°] |
image circle diameter [mm] |
Shutter/ mounting |
filter size |
length/max. diameter[mm] |
weight[g] |
|
Germinar-W |
6/4 |
240 |
9.0/? |
70 |
672a,b |
Copal 1, barrel |
? |
? |
? |
|
Apo-Germinar |
4/4 |
180 |
9.0/180 |
45-46b |
305a,b |
barrel |
? |
37/58 |
? |
|
Apo-Germinar |
4/4 |
375 |
9.0/? |
45-46b |
? |
barrel |
? |
? |
? |
|
Apo-Germinar |
6/6 |
900 |
9.0/? |
45 |
746 |
barrel |
? |
? |
? |
|
Apo-Germinar |
6/6 |
1200 |
? |
45 |
994 |
barrel |
? |
? |
? |
|
Tessar |
4/3 |
150 |
4.5/? |
? |
? |
barrel |
? |
? |
? |
|
Tessar |
4/3 |
165 |
4.5? |
? |
? |
barrel |
? |
? |
? |
|
Tessar |
4/3 |
508 |
4.5/? |
57 |
552 |
barrel |
? |
? |
? |
|
Tessar |
4/3 |
610 |
6.3 |
57 |
662 |
barrel |
? |
? |
? |
|
Apo-Tessar |
4/3 |
240 |
9/? |
? |
? |
barrel |
? |
? |
? |
|
Apo-Tessar |
4/3 |
300 |
9/? |
? |
? |
barrel |
? |
? |
? |
|
Apo-Tessar |
4/3 |
450 |
9/128 |
? |
? |
barrel |
? |
? |
? |
|
Apo-Tessar |
4/3 |
460 |
9/90 |
? |
? |
barrel |
? |
? |
? |
|
Apo-Tessar |
4/3 |
600(24”) |
9/? |
? |
? |
barrel |
? |
? |
? |
|
Apo-Tessar |
4/3 |
750 |
9/? |
43 |
591 |
barrel |
? |
? |
? |
|
Apo-Tessar |
4/3 |
900 |
9/? |
43 |
709 |
barrel |
? |
? |
? |
Meopta
LF lenses
The Czech Meopta company is mostly known for their
enlargers, but they also made cameras and a few taking lenses. The 135mm Largor
and the 210mm Belar are 2 LF lenses that came in (West-German) Prontor-S and
Compound shutters, respectively. They were sold together with the
“Magnola” 13x18cm technical camera, a copy of the 5x7” Linhof Technika. The
Largor was a double Gauss wide angle lens like the Kodak Wide Field Ektar; the
Belar is probably a Tessar type. All the other lenses listed below were
enlarger lenses. My main source was Meoptas
history web site, plus some other posts from the internet.
|
Lens name |
Lens elements/ groups |
focal length[mm] |
max./min. aperture |
coverage |
image circle diameter [mm] |
Shutter |
filter size |
length/max. diameter[mm] |
weight[g] |
|
Largor |
4/4 |
135 |
4.5/32 |
85° |
229 |
Prontor-S |
38mm push-on |
25.5/58 |
169 |
|
Belar |
4/3 |
210 |
4.5/? |
? |
? |
Compound |
62mm push-on |
? |
395 |
|
Belar |
4/3 |
180 |
4.5/? |
? |
? |
enlarging |
? |
? |
? |
|
Belar |
4/3 |
210 |
4.5/? |
? |
? |
enlarging |
? |
? |
? |
|
Correctar |
? |
165 |
4.5/? |
10x12cm |
? |
enlarging |
- |
? |
? |
|
Meopar |
? |
180 |
4.5/? |
10x15cm |
? |
enlarging |
- |
? |
? |
|
Meopar |
? |
210 |
4.5/? |
13x18cm |
? |
enlarging |
- |
? |
? |
|
Meopar |
? |
300 |
4.5/? |
18x24cm |
? |
enlarging |
- |
? |
? |
Russian
LF and process lenses
All of
those lenses came in barrel and were used for the “FK” cameras (13x18cm and
18x24cm) that were built until 1987. “IMESQRAP (Industar)” lenses are of the Tessar
type. Industar lenses usually have the Russian capitalized “I” followed by a
dash and a number engraved on the front, e.g.
I–37. Most of the
information listed below came from Dr. Martin Donau’s web
site on Russian lenses (in German) and from the web site of Marco Pauck
on the FK cameras.
|
Lens name |
Lens elements/ groups |
focal length[mm] |
max./min. aperture |
coverage[°] |
image circle diameter [mm] |
filter size |
length/max. diameter[mm] |
weight[g] |
Remarks |
|
Industar-4 |
4/3 |
210 |
4.5/? |
? |
? |
? |
? |
? |
Pre-WWII |
|
Industar-11 |
4/3 |
300 |
9/? |
45 |
249b |
? |
? |
? |
Process lens |
|
Industar-11 |
4/3 |
450 |
9/? |
45 |
373b |
? |
? |
? |
Process lens |
|
Industar-11 |
4/3 |
600 |
9/? |
45 |
497b |
? |
? |
? |
Process lens |
|
Industar-11 |
4/3 |
900 |
9/? |
45 |
746b |
? |
? |
? |
Process lens |
|
Industar-11 |
4/3 |
1200 |
9/? |
45 |
994b |
? |
? |
? |
Process lens |
|
Industar-13 |
4/3 |
300 |
4.5/? |
56 |
319b |
? |
? |
? |
|
|
Industar-37 |
4/3 |
300 |
4.5/? |
53 |
299b |
? |
? |
? |
|
|
Industar-51 |
4/3 |
210 |
4.5/? |
56 |
223b |
? |
? |
? |
|