Large format lenses from Docter Optic

(+ Carl Zeiss Jena/Jenoptik, Meopta, and Russian LF lenses)

 

By Arne Croell © 2002 for largeformatphotography.info

 

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.

 

 

Some history

 

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.

 

Apo-Germinar W

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.

 

Doctar WA

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

?

?

?

 

 

View or add comments


arne.croell@inemet.tu-freiberg.de