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.

A new full-frame mirrorless camera, Sigma FP, was launched in 2019 along with a range of L-Mount lenses and adapters.

The current line makes use of the Quattro sensor, a variant of the Foveon design that has a higher resolution top layer and lower resolution lower layers combined into a final image that is claimed to be equivalent to a 39 megapixel color filter array image.

The company claims that the Foveon Quattro technology produces a level of detail equivalent to that of a Bayer sensor with twice the pixel count.

In August 2013, Sigma announced that starting the following month, it would offer a mount conversion service for its newest "Global Vision" lenses—those with either an "A" (Art), "C" (Contemporary), or "S" (Sport) as part of their model name.

For a cost that varies with lens and market—from $80 to $250 in the U.S., not including shipping costs—owners can send their lenses to their local Sigma company, which in turn sends them to Japan for mount replacement, including calibration and optimization for the new camera system.