Michihiro Yamaki died in Tokyo on 18 January, shortly after celebrating the company's 50th anniversary.

Sigma was founded on 09 Sep 1961 with the development of the first ever rear attached lens converter. Yamaki developed this optical technology at a time when most photo enthusiasts believed that a lens converter could only be attached to the front of a camera lens.

The company grew from being the smallest of over 50 lens manufacturers in Japan to being one of the largest SLR lens manufacturers in the world, producing more than 50 lenses compatible with cameras developed by Canon, Sony, Nikon, Olympus and Pentax.

Sigma's goal has always been to make outstanding image quality accessible to all photographers, and it has done so by consistently working with Yamaki's ethos of producing high-quality, high-performance photographic technology at moderate prices.

In 2008, under Yamaki's direction, Sigma Corportation purchased Foveon, a US company known for developing the X3 image sensor technology found in the DSLR camera's that Sigma now produces.

Yamaki's contribution to the photography world was recognized by several accolades through his life, including the PMA Hall of Fame Award, the Golden Photokina Pink and the United Nations International Photographic Council Hall of Fame Award.

A spokesman for Sigma paid tribute to Yamaki stating that "Mr Yamaki will be sadly missed but his energetic, capable and compassionate leadership style will be carried forward by his son, Mr Kazuto Yamaki".