Cosina Company, Ltd.or Kabushiki-gaisha Koshina) is a Japanese camera and lens manufactuer. The company was founded by Mr. B. Kobayashi in 1959 as a lens factory under the name Nikō (or Nikoh). Though the company has produced cameras and lenses under its own name, it is better known for making equipment for resale under other company's brand names. Cosina has manufactured camera bodies for many well-known camera brands, including Canon, Contax, Nikon, Revue, Olympus, Vivitar, and Yashica. Cosina also manufactures the modern Voigtländer Bessa line of cameras and optics, along with the newly revived Zeiss Ikon rangefinder camera and lenses.

Cosina has a long history of manufacturing optical glass and is currently capable of producing glass and plastic aspheric lenses. Their factory maintains a glass furance that is heated to 1300 C, running 24 hours a day. All glass produced by Cosina today is lead-free eco-glass. Their current glass polishing technology is able to achieve sub-micron precision. They also have vacuum-deposition optical coating capabilities that are certified to meet Carl Zeiss lens standards.[1]

In Germany, a lot of Cosina cameras and lenses were marketed by Photo Porst, for many years Germany's biggest photo retailer and mailorder house under their house brand name Porst.

One of Cosina's more interesting camera designs was the E1 Solar, introduced in 1994. The E1, a 35mm film SLR, is powered by rechargeable batteries charged by a small solar panel atop the camera prism housing.

A recent Cosina-branded product was the SW-107, identical to the (silver) Bessa L except for a different top plate, made at the beginning of the Cosina Voigtländer era for areas where Cosina was not authorized to market the Voigtländer trademark. The 107 is hard to find now.

In 2005 Zeiss and Cosina announced a partnership whereby Cosina would manufacture the new Zeiss Ikon RF camera and most of the accompanying M mount lenses.