Sigma Corporation (株式会社シグマ Kabushiki Gaisha Shiguma) is a Japanese company, manufacturing cameras, lenses, flashes and other photographic accessories. All Sigma products are produced in the company's own Aizu factory in Bandai, Fukushima, Japan.
Although Sigma produces several camera models, the company is best
known for producing lenses and other accessories that are compatible
with the cameras produced by other companies.
The company was founded in 1961 by Michihiro Yamaki, who was Sigma's CEO until his death at age 78 in 2012.
Sigma produces products to work with cameras from Canon, Nikon,
Pentax, Sony, Olympus and Panasonic, as well as for their own cameras.
Sigma's digital SLRs, the SD9, SD10, SD14 and SD15 and the latest SD1
are unusual in their use of the Foveon X3 image sensor. All use the SA lens mount. The Sigma DP1 and DP2, high-end compact P&S cameras, also use the Foveon X3 image sensor, which gives them a much larger sensor than other cameras of this type.
Sigma is the world's largest independent lens manufacturer and is a family-owned business.