The Sigma SA-mount is a
lens mount
A lens mount is an interface – mechanical and often also electrical – between a photographic camera body and a lens. It is a feature of camera systems where the body allows interchangeable lenses, most usually the rangefinder camera, singl ...
by the
Sigma Corporation of
Japan
Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north ...
for use on their autofocus
single-lens reflex and
mirrorless
A mirrorless camera is a photo camera featuring a single, removable lens and a digital display.
The camera does not have a reflex mirror or optical viewfinder like a digital single-lens reflex (DSLR) camera, but may have an electronic vi ...
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, 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
The M42 lens mount is a screw thread mounting standard for attaching lenses to 35 mm cameras, primarily single-lens reflex models. It is more accurately known as the M42 × 1 mm standard, which means that it is a metric screw thread ...
, and the ''
SA-1'' of 1983 with
Pentax K-mount.
Mechanically, the (inner) SA-mount is similar to the
Pentax K-mount as well, but with a
flange focal distance
For an interchangeable lens camera, the flange focal distance (FFD) (also known as the flange-to-film distance, flange focal depth, flange back distance (FBD), flange focal length (FFL), back focus or register, depending on the usage and sourc ...
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
Leica Camera AG () is a German company that manufactures cameras, optical lenses, photographic lenses, binoculars, rifle scopes and microscopes. The company was founded by Ernst Leitz in 1869 (Ernst Leitz Wetzlar), in Wetzlar, Germany.
...
L-mount, as members of the
L-Mount Alliance alongside
Panasonic.
Compatibility
M42-mount lenses can be mounted via adapters utilizing the SA inner bayonet.
Despite of the physical similarities
Pentax K-mount (PK) lenses can't really be fitted straight onto the SA-mount as well, once the protruding AA lever and AA protector outcrop are removed, though 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
For an interchangeable lens camera, the flange focal distance (FFD) (also known as the flange-to-film distance, flange focal depth, flange back distance (FBD), flange focal length (FFL), back focus or register, depending on the usage and sourc ...
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.
[ ]
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
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
Lenses
All SLR lenses manufactured by
Sigma
Sigma (; uppercase Σ, lowercase σ, lowercase in word-final position ς; grc-gre, σίγμα) is the eighteenth letter of the Greek alphabet. In the system of Greek numerals, it has a value of 200. In general mathematics, uppercase Σ is used as ...
since 1993 are available for the SA-mount. A partial listing can be found
here.
See also
*
Kodak DCS Pro SLR/c
References
{{reflist
Lens mounts
Sigma Corporation