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BBT Krauss/Huet 7 x 50; with an unique eye ocular distance bar
Contents
Introduction
1. A short history of the BBT Krauss
2. BBT Krauss 7x50 binocular - model 302-10
- External features
- Internal features
3. Other models BBT Krauss
- 16x50 models
4. 7x50 models produced for other countries
Introduction
The binocular is unusual in many ways. It was produced in France by Huet, BBT Krauss. The BBT Krauss 7 x 50 model is not easy to find. We have seen and heard from other collectors, that they have the model BBT Krauss 16 x 50 or models produced for other countries. The Krauss 7 x 50 was produced for Swedish Army and for Danish Army – Air force as well.
This model is rarely seen with the eye ocular distance bar and a specific construction of eyecups.
It takes some time to find a short history of the binocular and the company which produced this fine optic.
1. A short history of the BBT Krauss
The Krauss Company was merged with other companies for decades.
In the periods between the wars some French Companies closely worked with PZO (Polish Optical Industries), among them were:
- Société des Establissements Krauss (SEK) – the company sold to PZO the technical documentation for the production of scissors binoculars for further development ; the next field of the cooperation between PZO and SEK was military photographic equipment;
- Barbier, Bernard ET Turenne (BBT).
In the PZO factory’s document it is specified that those two companies made a fusion in 1935, and became Company BBT Krauss.
The French Krauss Company was founded in 1880s by E. Krauss (Eugene Krauss). It was a camera and lens maker factory. The company possessed a license to produce lens models of Carl Zeiss. It was located in Paris.
Another Krauss Company – G.A. Krauss (Gustav Adolf Krauss) was as trading and manufacturing photographic items, and it was located in Stuttgart since 1895.
Looking more closely at the factory’s technical documentation of the 16 x 50 BBT Krauss binoculars -produced in 1939, kindly send by Bruno Pietrini, we can see that BBT Krauss was a part of the Huet Company or producing in cooperation with Huet.
Under the designation of the binocular are indicated two producers of the binocular: Huet and BBT.
The production number of the binocular is in two figures as well: one BBT number and second as Huet number.
Technical documentation of BBT Krauss 16 x 50; Picture copyrights Peter Pietrini
Technical documentation of BBT Krauss 16 x 50; Picture copyrights Peter Pietrini
16 x 50 BBT Krauss - Huet from a French collection
In 1931 -1933 Huet advertised other binocular models.
 
The Huet advertisements 1931- 1933
2. BBT Krauss 7x50 binocular - model 302-10
- External features
The binocular has an alloy aluminum body with black textured leatherette.
The binocular dimensions are – 20 x 21 x 7 cm and weight - 1,107 kg.
Size of the leather box is: 23 x 23 x 11 cm.
The binocular has a unique eye ocular distance bar, connected to eye lenses tubes. The bar is to maintain the position of the rubber eyecups in relation to each other. The bar could be fit from 56 to 72 mm.
  
 
7x50 BBT Krauss, No 110.843 from our collection; Pictures copyrights Anna Vacani
The rubber eyecups are easy removable and fixed on metal push- on mount. The rubber eyecups are constructed in a specific way. They consist of three parts: top ring, rubber and a metal structure bottom tube with cut-out hole on the distance bar arm. The rubber shell is inserted between two metal parts. The whole structure is connected by a few screws.
 
The rubber eyecups from our binocular; Picture copyrights Anna Vacani
The description on the plates is;
Left: 302-10 and magnification 7 x 50
The left plate of our binocular; Picture copyrights Anna Vacani
The binocular does not have “Miliemes” word on the left plate. Other model 7x50 probably later production has this word - Miliemes = graticule graduations, graticule with horizontal and vertical scales in the right ocular for artillery use.
Right plate description is; No 110.843 and BBT Logo – BBT Krauss France.
The right plate of our binocular; Picture copyrights Anna Vacani
The oculars could be individually focused: graduation from -5 to +5 diopter. Two yellow color filters, removable are supply and stored in the cover of original leather case.
The binocular and the leather case from our collection; Picture copyrights Anna Vacani
 
The yellow color filter inserted in the left ocular; Pictures copyrights Anna Vacani
We have not seen other and later models with this unique eye ocular distance bar, except the models 16 x 50 produced from 1930s – and our model 7 x 50 – probably was produced just after the war.
The distance bar lets a viewer use the binocular in an easy way. It allows the rubber eye cups to adjust automatically to the correct users’ eye width position.
- Internal features
It is a standard Porro I model. The same prism set up as a 7 x 50 Carl Zeiss Binoctar.
7 x 50 BBT Krauss 302-10 model – prism system; Production No 110.843; Copyrights picture Anna Vacani
The optical arrangement is similar to the model 16 x 50 visible in the schematic from the technical documentation.
Technical documentation of BBT Krauss 16 x 50; Picture copyrights Peter Pietrini
The optic is coated; the objectives are coated from both sides.
7 x 50 BBT Krauss 302-10 model – objectives; Production No 110.843; Copyrights picture Anna Vacani
The exit pupil is 7, 1 mm.
A graticule is not fitted in our binocular.
The optical performer is very good; the picture is clear and sharp. The field of view is poor; it is very narrow – 7, 1 degree.
3. Other models BBT Krauss
- 16x50 models
16 x 50 BBT Krauss with oculars distance bar from Dr Hans Seeger collection; Copyrights picture Dr Hans Seeger
The eyecups of the binocular are not complete, the eye rubbers were removed. Presumable the rubber s were deteriorated or they were removed for improvement of the binoculars performer, as eye relief is not very long on the 16 x 50 models. The body design is the same as model 7 x 50.
The descriptions on the plates are different from model 7 x 50. On the left plate specifies the field of view as a very wide (Grand Champ Desigrates). The right plate description indicates that the binocular was produced for the French Army – M.G. (Ministère de la Guerre – Ministry of the War).
The number is - 382.
The BBT Krauss logo is identical to model 7 x 50.
In 1930’s Huet produced 16 x 50 binocular - ‘Aerix’ model with a distance bar. Description of the binocular does not indicate of cooperation with BBT Krauss Company.
16 x 50 Huet model ‘Aerix’ with oculars distance bar from Dr Peter De Laet collection; Copyrights picture Dr Peter De Laet
The binocular has a very wild field of view (Grd champ), but without micrometer (sans micrometer).
Our model does not have as detailed description: Grd champ; sans micrometer.
16 x 50 Huet model ‘Aerix’ the left plate; Copyrights picture Dr Peter De Laet
This model was produced for Ministry of the War - M.G. Ministère de la Guèrre.
16 x 50 Huet model ‘Aerix’ the right plate; Copyrights picture Dr Peter De Laet
The binocular is missing the detachable rubber eyecups assembly.
Dr Peter De Laet says about this model: “As far as I know, the first Aerix 16x50 series were produced by Huet for the French Gendarmerie, mounted police”
Presumably, it was not a favorite pair of binocular, among mounted policemen. It is difficult to use that kind of high power 16 x 50 binocular riding a horse.
4. 7x50 models produced for other countries
BBT Krauss France produced 7 x 50 binoculars for Danish and Sweden Army. None of them have a distance bar. Frank Lagorio describes the Danish model: “M/50 = Danish Army/Air force Model 1950. FKF under crown = Forsvarets Krigsmateriel Forvaltning
(Danish War Material Administration). Milliemes = graticule graduations; Graticule with horizontal and vertical scales in the right ocular for artillery use; fully coated optics.”
The Danish marks are inserted into the rain cover as well.
 
7 x 50 BBT Krauss produced for Danish Army; Picture from Frank Lagorio collection; Copyrights picture Frank Lagorio
After the war the BBT Krauss model was produced for Swedish Army as well.
7 x 50 BBT Krauss produced for Swedish Army; Picture from Sven-Olof Nyman collection; Copyrights picture Sven-Olof Nyman
A description of this model is different from Danish model. On the left plate is BBT Krauss logo.
7 x 50 BBT Krauss produced for Swedish Army; the left plate; Picture from Sven-Olof Nyman collection; Copyrights picture Sven-Olof Nyman
The right plate shows three Swedish crowns and 7 x 50 markings.
7 x 50 BBT Krauss produced for Swedish Army; the right plate; Picture from Sven-Olof Nyman collection; Copyrights picture Sven-Olof Nyman
The binocular has not original rubber, as the eye tube indicates.
7 x 50 BBT Krauss produced for Swedish Army; the left eye tube; Picture from Sven-Olof Nyman; Copyrights picture Sven-Olof Nyman
We hope this brief article will help all binoculars collectors find out more about this amazing model.
If the readers of this short dissertation possess any documents or other models of Huet/BBT Krauss with this unique eye ocular distance bar, we will be happy to hear and add some pictures and information to this article.
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