Carl Zeiss AG, often shortened as Zeiss, is a Germany-based manufacturer of optoelectronics and optics systems. Founded back in 1846 by optics expert Carl Zeiss, it is considered as one of the oldest manufacturers of binoculars that are still operating on the top of the sport optics market. Since its conception, Zeiss has invented and patented several products and features in the optics domain, which other premium brands have since introduced in their line of premium products. Currently, the company’s headquarters is located in Oberkochen, a small town in southern Germany. Notable inventions by Zeiss scientists include:
Abbe-Koenig prisms: Abbe-Koenig prisms are a special sub-category of roof prisms that are predominantly used in sport optics for inverting the image captured by the objective lens by 180 degrees. Unlike the Schmidt-Pechan roof prisms, these binoculars have fewer reflective surfaces which is the reason behind their supremacy in light transmittance. The Abbe-Koenig prisms were invented by two scientists, Ernst Abbe and Albert Koenig, who worked together on the development of prisms at Zeiss in the 1800s.
T* Coatings: Introduced in the 1930s, the T (transparent) coating was Zeiss’s signature multi-coating technology for minimizing the 3-8% loss of light when it hits surfaces of optical components, such as lenses and prisms. It is said to transform the glass surfaces to be completely transparent to light. Since its invention, Zeiss has continued to enhance this coating and in the 1990s, the multi-coating was officially rebranded as T* coating. It is now proudly used in all Zeiss products, including sport optics, digital camera lenses, and movie film lenses.
FL Concept: The FL Concept by Zeiss is an optics technology that guarantees a unique viewing experience for long-distance objects by minimizing chromatic aberration and providing high color fidelity. The FL concept features objective lenses made of low-dispersion fluoride-ion glass and is usually paired with T* lens coatings for minimized reflection and P* phase-corrective coatings for prisms to provide an unparalleled hunting experience.
SF Concept: The Smart-Focus Concept, or SF, features the focusing wheel positioned on the newly designed triple-link bridge on binoculars. This position aligns with the usual position of index fingers and makes focusing seamless. Another feature of this concept is a large and ultra-smooth focusing wheel which offers an easy grip and precise control of the focus setting, thereby enabling the user to pinpoint details on varying distances easily.
In 1846, the foundation of Carl Zeiss AG was laid in the form of an optics workshop by optician Carl Zeiss in Jena, the largest city in Thuringia, Germany. He originally worked on creating microscopes in his small workshop but by 1861, the workshop grew into a small factory of around 20 workers and came to be known as one of the best optics-instrument makers of the time. The microscope business gained further momentum and by the year 1866, the Zeiss had already sold their 1000th microscope.
It was not much later when Ernst Abbe, a renowned German optical scientist, and Otto Schott, a notable glass technologist became part of the company in 1866 and 1884 respectively. Together, the three optics experts worked on several optical instruments and various glass components, like the Abbe-Koenig prism, apochromatic lens, and the first refractometer. Ernst Abbe became the director and subsequently, the co-owner of the company in later years. In 1889, the name of the company was changed to Carl-Zeiss-Stiftung. Zeiss is one of the oldest and important manufacturers to incorporate the “Made in Germany” slogan on its products.
Before the advent of World War I, Zeiss became a household name in the production of cameras and optics equipment. Zeiss Ikon and dozens of camera products were part of the manufacturing lines, including products for other brands and factories. Some products were also manufactured at the Dresden city factory, such as the first 35-mm single-lens reflex camera. The company acquired the optics manufacturer Hensoldt AG in 1928 and started producing sport optics equipment not long after. The acquisition sometimes resulted in twin products being marketed under both the Zeiss and Hensoldt brands.
Zeiss in East and West Germany
During the Nazi Germany regime, several companies, including Zeiss, exploited forced labor under the Zwangsarbeiter program. After the Second World War, the city of Jena was occupied by American armed forces. When Dresden and Jena were decided to be incorporated into the Soviet Occupation Zone, the US army shifted some components of the Zeiss’s Jena factory to the Contessa-Werke Manufacturing facility in Stuttgart Germany while the remainder of the business was rebuilt as Kombinat VEB Zeiss Jena.
Soon after the war in 1946, the business was re–established in the town of Oberkochen in southwestern Germany by the name of Opton Optische Werke Oberkochen GmbH. The company was renamed to Zeiss-Opton Optische Werke Oberkochen in 1947 and later to Carl Zeiss, but the products were still labeled as Opton to be sold in the eastern bloc countries, including East Germany. On the other hand, products manufactured at the Zeiss Jena were marketed as either Zeiss Jena or Jena in the western world. VEB Zeiss Jena was renamed Zeiss Jena GmbH in the years leading to the German unification.
When East Germany and West Germany were reunited in 1990, Zeiss Jena became Jenoptik Carl Zeiss Jena GmbH and in 1991, the Oberkochen’s Carl Zeiss AG took over the Jenoptik’s microscope and precision equipment business division, thereby effectively reuniting the pre-World War II Carl Zeiss. The remaining components of the business were split off for manufacturing optics and optoelectronic components.
The Carl-Zeiss-Stiftung group presently owns Schott AG, a German manufacturer of glass and glass-ceramics products. The company was founded in Jena, Germany by Otto Schott AG along with Carl Zeiss, his son Roderich Zeiss, and Ernst Abbe by the name Glass Technical Laboratory Schott & Associates in 1884. Schott AG has several manufacturing facilities spread across Germany.
Current production facilities
Presently, Carl Zeiss AG has two main locations in Germany and one in Hungary for the design and manufacturing of Zeiss Sport Optics.
1. Wetzlar factory
The main manufacturing facility for most Zeiss products, including sport optics, is located in Wetzlar, Germany. Along with Zeiss, the city of Wetzlar is home to the manufacturing sites of several notable optics brands – especially, Leica, Minox, Schmidt & Bender, and Leidolf. Our team visited the factory in September 2017, and the tour included several activities, such as a visit to their main manufacturing line, near-site private shooting range, lecture-room briefing about main and upcoming Zeiss technology, and finally, a sightseeing trip of the Wetzlar city, especially the place where the first-ever picture was taken by Oskar Barnack with a Leica Camera in 1913.
Carl Zeiss AG originally focused on the manufacturing of microscopes which later included Zeiss cameras, lenses, and prisms. It was not until the company acquired Hensoldt AG in 1928 when Zeiss dived into the manufacturing of sport optics products – binoculars and riflescopes.
Hensoldt AG was originally founded in 1849 by Moritz Carl Hensoldt and his brother-in-law Carl Kellner as a manufacturer of telescopes and optical instruments in Wetzlar. The company was initially called M. Hensoldt & Soehne AG. Carl Zeiss AG originally acquired a partnership in Hensoldt AG in 1928 and gradually acquired all rights in the later years until it became a fully-owned Carl-Zeiss-Oberkochen company in 1968. After the acquisition, the Hensoldt AG name was kept through the twentieth century and optics products, such as binoculars and telescopes were marketed under both Hensoldt and Zeiss brands.
In the years following the Second World War, Zeiss binoculars were produced at both Oberkochen and Wetzlar locations. The first binoculars were produced at the Oberkochen factory in 1953, but all binoculars production was relocated to the Hensoldt-Wetzlar factory not much later in 1964. The Hensoldt brand was abolished in 2006 and the sports optics company was officially rebranded as Carl Zeiss Sports Optics GmbH.
The myth surrounding Abbe-Koenig prisms
During our visit to the factory, we were told of a claim surrounding the manufacturing of Zeiss’s signature Abbe-Koenig prisms that said: only three female workers knew how to operate the machine for the production of Abbe-Koenig prisms at the Zeiss factory. The management of the factory rebuffed this claim as nothing but a myth.
The series of manufacturing processes taken at the Wetzlar factory are as under:
Carl Zeiss Sport Optics AG has been in a partnership with sister company Schott AG since the very beginning. Schott glasses have been actively used in almost all Zeiss products, including microscopes, telescopes, cameras, binoculars, lenses, and other optoelectronic products. The Wetzlar factory procures glass directly from Schott AG’s Mainz factory, especially the NBK-47 variant of glass in the form of blocks for the manufacturing of lenses and prisms respectively. Zeiss also uses glass from the Japan-based glass manufacturer, Ohara, in optics products.
The glass blocks are sliced and then pass through a series of grinding operations before they take the shape of prisms and lenses. Manufacturing of glass components is a critical process that requires sophisticated grinding machines and highly skilled labor for precise production. After the grinding procedure, the glass components are thoroughly washed in de-ionized water and alcohol until they are free from any grinding-residue or dirt particles. The final step is the coating process.
To minimize the loss of light due to reflection and scattering and ensure sharp images with high contrast, all modern binoculars feature a form of an optical coating on both surfaces of the lens and some surfaces of prisms. A decent coating can reduce the problems of loss of light down to 4% from 8%, which is significant, especially for low-light viewing. Since this applies to all lens and prisms surfaces, the resulting improvement in performance is highly noticeable. The ingredients for the signature LotuTec® Zeiss coating are kept a secret but all we know is they use a combination of magnesium and aluminum alloys to create a thin layer on the surface of lenses and prisms.
For binoculars, Zeiss primarily uses a specific magnesium alloy which is known to be light-weight and robust enough for protecting the delicate glass components. Another advantage of using magnesium alloy is corrosion-free nature. There are several computer-programmed lathe and 5-axis milling machines at the metal production facility which handle the rigorous task of cutting and machining metals to form the shapes of binoculars and riflescopes. The two barrels of binoculars are machined separately at this stage.
The next step is metal anodizing but before that, the surfaces are strain-hardened and evened out by the use of moving ceramic marbles in a large container. After that, the housings are taken for surface glass blasting. This step further evens the surfaces, so that they are smooth enough for anodizing. From this stage onwards, the housings are not handled without proper gloves to avoid dirt or fingerprints. In anodizing, a thin oxide layer is introduced on the surface of the metal to protect it from unwanted abrasion and improve its corrosion resistance.
Anodizing is the last step before all components are sent for assembly.
After the metallic and glass components are ready, they proceed to the assembly stage. The assembly processes for all sport optics components are painstaking and time-consuming since they require precise alignment in a completely dirt-free environment. Trained individuals are responsible for one particular component, and instead of a mass production setup, Zeiss employs a station-based approach in which items are produced by one worker at a time before they are sent to the next stage.
Even in the era of automation and digitalization, the assembly processes for binoculars, spotting scopes, and riflescopes are crafted by hands, which shows the amount of work and time Zeiss invests in each product. Once the devices are assembled, they are taken for an essential process of nitrogen-purging. Once the binoculars and other optics products are sealed, they have to pass through a series of quality control inspections, which again includes hand inspection along with high-tech inspection equipment. The inspection procedure of light transmission tests, gas leakage tests, extreme temperature tests, and of course the check of magnification power.
Innovation and technological advancement make the backbone of Carl-Zeiss-Foundation. Since the beginning, Zeiss has worked on developing outstanding technologies for optics and optoelectronics products. They achieve this through an innovation-induced work culture, highly trained employees, and the re-investment of about 10 percent of the annual revenue each year.
The rigorous research and development activities have resulted in several outstanding features, which have been timely patented. Notable examples of innovation at Zeiss are Abbe-Koenig prisms, FL concept, Extreme Ultraviolet (EUV) Lithography, apochromatic lens, T* coating, and several others.
2. Oberkochen factory
The headquarters of the Carl-Zeiss-Foundation is located in Oberkochen and all marketing and sales operations are carried out there, including the manufacturing of some products. Until 2018, binoculars, telescopes, riflescopes, and all other sport optics were only manufactured at the Wetzlar factory, but Zeiss shifted production of some components at Oberkochen too. Presently, some sport optics are produced at Oberkochen too, along with the predominant manufacturing of Zeiss camera lenses, semiconductor technology products, and optical lithography.
Other attractions at the Oberkochen factory include the Zeiss Museum of Optics. The large 1000-square meter exhibition space features numerous optical instruments from the past, including early microscopes, binoculars, lens, and telescopes. The replica of the Zeiss lens that went to the Moon on Apollo 11 is also proudly displayed. The museum is also home to the Zeiss planetarium, which is the smallest in the world with a contrast ratio of 2.5 million to 1. There is also a large restaurant area for employees and visitors at the factory location.
Above the museum is the production area for signature Zeiss motion camera and photography lenses. Employees at the manufacturing floor follow the Japanese philosophy of Lean Manufacturing instead of a mass-production setup. Each working area is in a U-shaped configuration to increase the accessibility of essential tooling. Similarly, machines at the mechanical workshop are also arranged in a U-shaped configuration. This is where the housings for lenses and other products are developed.
Most assembly and inspection operations are carried out by expert hands although critical checks require sophisticated equipment for precise inspection. Next are the service department and an on-site lens training program where technicians from around the world become certified technicians.
3. Factory in Mátészalka, Hungary
Zeiss manufacturing facilities are spread at key locations all over Europe, including the factory in the city of Mátészalka, Hungary. The Zeiss group acquired ownership of the Hungarian Optical Works CO., or MOM, in the 1940s and completely purchased the factory building in 1992. The factory produced optical lenses for different uses and Zeiss turned it into one of the finest manufacturing facilities in Europe.
In addition to lenses, the factory initially manufactured few models of binoculars from scratch, starting with the first generation of Zeiss Conquest binoculars. The factory was downsized in 2007 and the sport optics manufacturing was scaled down to include only Zeiss pocket binoculars and monoculars. The factory mainly focuses on manufacturing some plastic and metal components for products manufactured at the Wetzlar, Oberkochen, and Jena facilities.
Series and their origin
The Zeiss sport optics products are mainly produced in Germany while only monoculars and pocket binoculars are produced in Hungary.
The following binoculars series are produced in Germany:
The Conquest HD binoculars are perfectly designed for a multitude of activities. They feature the highest-quality optics, Zeiss T* coating, LotuTec water-resistance coating, nitrogen purging and a robust armor for protection from accidental falls. Conquest HD binoculars are available in the following configurations:
Conquest HD: 8×56, 10×56, 15×56, 8×42, 10×42, 8×32 and 10×32 binoculars
The Victory HT series is another line of premium Zeiss binoculars. With 54 mm objectives and the iconic Abbe-Koenig prisms, these binoculars provide unparalleled light transmittance of 95 % along with a high color fidelity. Despite the larger objectives, engineers at Zeiss have come with a compact and lightweight design which makes these the perfect choice for bird watchers. Victory HT series is available in 8×54 and 10×54 configurations.
The Victory SF binoculars feature the patented Zeiss’s SmartFocus design. Along with the centrally-located focus knob, these binoculars feature an ergonomic construction along with a balanced weight-distribution for hours of comfortable viewing. Additionally, they guarantee well-lit images even in the darkest of dawns and dusks thanks to brilliant optics. Victory SF series is available in the following configurations:
Victory SF: 8×42, 10×42, 8×32 and 10×32 binoculars
The Zeiss 20×60 S binoculars are designed for vast distances. The large 60 mm objective lens brings in enough light for the binoculars to work in all daylight and evening conditions. The instability problem with higher magnifications ruins a perfectly fine excursion trip, but with a built-in gimble mechanism in Zeiss 20×60 binoculars, the view through the eye-piece is stabilized with the push of a button. Additionally, these binoculars feature Porro-prisms which are known for excellent light transmission.
The Mátészalka factory presently manufacturers the following two series of Zeiss pocket binoculars:
The Conquest pocket series offer the amazing features of the original Conquest series, such as the T* coating, waterproofing, and enhanced light transmittance, in a compact pocket-sized construction. Additionally, a rubber armor surrounds the housing for protection. Conquest pocket binoculars are no longer produced by Zeiss. They were available in 10×20 and 8×20 configurations.
Weighing only 290g, the Victory Pocket binoculars are designed to be pocket-sized while providing the same features of the premium Zeiss series. They feature the T* and LotuTec coatings for enhanced light transmittance and weather protection along with HD glass optics for ultimate viewing. Victory Pocket binoculars are available in 8×25 and 10×25 configurations.
The manufacturing of some of the Terra series binoculars is done in China. The pocket models are however produced in Japan. They are designed to be easy to use, compact, and reliable for all types of weather and terrain. With an entry-level price, the Terra series is the perfect entrance to the world of Zeiss optics. Despite the price, they offer premium features, such as nitrogen-purging and durable construction. The Terra series is available in the following configurations:
Terra ED – 10×42, 8×42, 10×32, 8×32, 10×25, and 8×25 binoculars.
Despite the spread of Zeiss production facilities all around the world, most of their sport optics products including binoculars are still produced in Germany, while only the pocket series are produced in Hungary. Zeiss was one of the first optics manufacturers to brand its devices with “Made in Germany” words and many of Zeiss binoculars still carry the brand, especially the outstanding Victory HT and Victory SF binoculars.
The main Zeiss sports optics factory is located in Wetzlar city, which has now become the hub of German sports optics manufacturing. The presence of several optics manufacturers like Leica, S&B, Minox, Blaser, and Kaps along with Zeiss in the city has turned it into the center of European optics which proudly supplies products to more than 180 countries around the world.
is an experienced author from the field of sports optics. He writes articles and reviews about binoculars, spotting scopes, rifle scopes, long range shooting and other topics for magazines like Lovec and Optics-Info.com blog. Currently, he is a member of Optics Trade team.