The Emil Busch A.-G. was a camera and lens maker based in Rathenow, Germany.


In 1792 the pastor Johann Heinrich August Duncker (1767-1843) of Rathenow began to make optical instruments and sold them in Germany. In 1801 he got the permission from the Prussian King to extend his business to industrial dimensions. He employed orphaned children and war invalids in his Optische Industrie-Anstalt. From a bankrupt optical plant in Neuruppin he bought a big multiple-lens grinding machine. He disassembled it and made his own grinding machine from the parts. He even received a patent on it. With low wages and piece-work he could produce cheaply. The first products were spectacles which were sold through specialised shops instead of by house-to-house salesmen. Duncker gave glasses for free to poor people.

When his son Eduard (1797-1878) took over the company in 1819 it had begun to make auricular tubes. In the 1840s it started to make modern spectacles with steel frames. The company then had skilled workers instead of children and war invalids, but many of them had to work at home because the company's rooms were not sufficient. Its products were sold through trade fairs. In 1843 it made 250,000 lens elements and 40,000 glasses frames which were sold through 300 shops between New York and Moscow.

Since Eduard Duncker and his wife had no children he sent his nephew from Berlin Emil Busch (1820-1888) back to Berlin for an apprenticeship in optics. In 1845 Busch took over the company. In 1852 he began to produce cameras. In 1856 the company got its first steam engine. In 1865 it started making its newly invented wide angle lens Pantoscop and won a prize for its photographic products. In 1872 the Optische Anstalt Rathenow became the stock market company Emil Busch A.-G. . It got its optical glass from Zeiss. A cartel between the companies existed. The company then had larger buildings with better working rooms, including bathing rooms and a first aid station, but still a lot of home-workers. In 1877 Emil Busch and Eduard Duncker founded a support foundation for Busch workers. They made provisions for the case when the company should be closed one day. Then a good part of its money should be spent for social and educational purposes.

In 1896 the 163 optical businesses were registered in Rathenow, many developed out of home work-places of Busch employees. Around 1900 the town was a centre of optical industry in Germany. Among Busch's products was a casket with a lens tube and a set of lens elements which could be combined in several focus variants as complete lens, the Busch Vademecum. Since 1900 or 1910 several Emil Busch products were badged ROJA or Roia, for example the Roia Spiegelreflex-Kamera. In 1927 the majority of shares of the company were taken over by Zeiss. E. Busch kept making cameras but quit lens making.

At the end of WWII the company was destroyed. The East-German government founded the VEB Rathenower Optische Werke and the VEB Augenoptik "Hermann Duncker" instead. After German reunification in 1989 the optical industry businesses of Rathenow were reduced from 4000 to 800 workers.