{{Short description|Lens mount by Sigma corporation}} {{redir|SA-mount|another camera mount sometimes also abbreviated as "SA"-mount|Sony A-mount}} The '''Sigma SA-mount''' is a lens mount by the Sigma Corporation of Japan for use on their autofocus single-lens reflex and mirrorless cameras. It was introduced with the ''SA-300'' in 1992. Originally, the SA-mount was a dual-bayonet mount with inner ('''SA-IB''') and outer ('''SA-OB''') bayonets, the latter being a feature intended to mount heavy telephoto lenses,<ref>SA-300 owner's manual</ref> but never utilized by Sigma and consequently dropped with the release of the ''SD14'' in 2007.
There were two precursors to the introduction of SA-mount cameras, the manual-focus Sigma Mark-I in 1976, which still featured a M42 screw lens mount, and the ''SA-1'' of 1983 with Pentax K-mount.
Mechanically, the (inner) SA-mount is similar to the Pentax K-mount as well,<ref>{{cite web |url=https://stephen-westin.com/misc/sigma-mount.html |title=Comparison: Sigma SA mount vs. Pentax K |author=Stephen H. Westin}}{{dead link|date=May 2025|bot=medic}}{{cbignore|bot=medic}}</ref> but with a flange focal distance of 44.00 mm, identical to that of the Canon EF-mount. Like the EF-mount, the SA-mount uses electrical communication between body and lens, and in fact uses the same signalling lines and protocol as the EF-mount, despite the physical incompatibility. Sigma has long produced EF-mount lenses for Canon cameras, and thus had the ability to use this protocol.
All Sigma SLRs and DSLRs can use manual focus lenses too, which have no electrical communication between body and lens.
In September 2018, Sigma announced that they will stop the development of SA-mount cameras and focus on the Leica L-mount, as members of the L-Mount Alliance alongside Panasonic.<ref>{{Cite news|url=https://www.ephotozine.com/article/sigma-set-to-axe-sa-mount-cameras--32752|title=Sigma Set To Axe SA Mount Cameras|work=ePHOTOzine|access-date=2018-09-26}}</ref>
== Compatibility ==
M42-mount lenses can be mounted via adapters utilizing the SA inner bayonet.
Despite the physical similarities Pentax K-mount (PK) lenses can't be fitted straight onto the SA-mount as well. If the protruding AA lever and AA protector outcrop are removed, the fit is slightly loose as the SA-mount has a slightly bigger bore than the PK-mount. However, due to the difference in registration distance scale focusing isn't possible and the close focusing capabilities will be reduced.
Utilizing the SA-OB bayonet mount (on camera bodies supporting it), Nikon F-mount can be fitted and used via a JTAT mount adapter developed by Kazuo Suzuki, Tachibana Seisakusho.<ref>{{cite web |url=http://www.jtat.com/sd/sd_main/SD_Nikon.html |title=SD_Nikon.gif |website=www.jtat.com |url-status=dead |archive-url=https://web.archive.org/web/20051001044343/http://jtat.com/sd/sd_main/SD_Nikon.html |archive-date=2005-10-01}} </ref>
In digital cameras, it is important to make sure that the rear of an adapted lens never hits the camera's dust protector filter when focused to infinity.
== Lens adaptations == {{anchor|MC-11|MC-11 SA-E|MC-11 EF-E}}Newer lenses with Sigma SA-mount can be used on newer Sony E-mount cameras (for example, the Sony ILCE-7 series, the ILCE-5000, ILCE-6000 etc.) using the Sigma MC-11 SA-E mount adapter, introduced in 2016. (A similar Sigma MC-11 EF-E adapter is available to mount Canon EF-mount lenses on Sony E-mount cameras.) The adapters support autofocus, image stabilization and electronic aperture control.
==Camera bodies== {| class="wikitable" !Body !Release date !Mount !Sensor |-align="center" |colspan="3"|'''Film (24×36 mm)''' |- |SA-300/SA-300 QD |1992 or 1993 |SA-IB and SA-OB |N/A |- |SA-300N/SA-300N QD |1994 |SA-IB and SA-OB |N/A |- |SA-5/SA-5 QD |1997 |SA-IB and SA-OB |N/A |- |SA-7/SA-7 QD |2001 |SA-IB and SA-OB |N/A |- |SA-9/SA-9 QD |2001 |SA-IB and SA-OB |N/A |- |SA-7N/SA-7N QD |2002 |SA-IB and SA-OB |N/A |-align="center" |colspan="3"|'''Digital (13.8×20.7 mm)''' |- |SD9 |2002-10 |SA-IB and SA-OB |Foveon X3, 1512×2268 pixels |- |SD10 |2003-12 |SA-IB and SA-OB |Foveon X3, 1512×2268 pixels |- |SD14 |2007-03 |SA-IB only |Foveon X3, 1760×2640 pixels |- |SD15 |2010-06 |SA-IB only |Foveon X3, 1760×2640 pixels |- |-align="center" |colspan="3"|'''Digital (15.7×23.5 mm)''' |- |SD1 |2011-05 |SA-IB only |Foveon X3, 3200×4800 pixels |- |SD1 Merrill |2012-02 |SA-IB only |Foveon X3, 3200×4800 pixels |- |SD Quattro |2016-02 |SA-IB only |Foveon Quattro, 3616×5424 pixels |- |-align="center" |colspan="3"|'''Digital (17.9×26.7 mm)''' |- |SD Quattro H |2016-02 |SA-IB only |Foveon Quattro, 4128×6192 pixels |}
==Lenses== All autofocus SLR lenses manufactured by Sigma since 1989 are available for the SA-mount. A partial listing can be found here.
==See also== *Kodak DCS Pro SLR/c
==References== {{reflist}}
Category:Lens mounts Category:Sigma Corporation