Sigma SA mount
Sigma's own mount, built around Foveon sensors that record red, green and blue at every location instead of interpolating them. At base ISO the colour and detail are genuinely unlike anything else; above ISO 400 they fall apart. Sigma announced the end of SA-mount bodies in 2018 when it joined the L-Mount Alliance, and the last SA lenses shipped that year. Nearly every Sigma DSLR lens was made in this mount, which means a large lens pool for seven bodies nobody else can use.
8 bodies and 46 lenses tracked. Lowest used prices pulled daily from the major used-gear sites.