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The Sigma SD14 is a digital single-lens reflex camera produced by the Sigma Corporation of Japan. It is fitted with a Sigma SA mount which takes Sigma SA lenses. The camera was announced on August 29, 2006 with a "teaser" advertising campaign〔(【引用サイトリンク】 title=Sigma-SD14.com )〕 and was unveiled at the photokina trade show in Cologne, Germany on 2006-09-26. After production delays, Sigma announced the official release of the SD14 to be on March 6, 2007.〔(【引用サイトリンク】 To our valued customers who waited patiently for the SD14 camera )〕 Sigma has released sample images on their website.〔(【引用サイトリンク】 Sigma SD14: Sample Image Gallery )〕 Contrary to most consumer cameras, which use color sensors based on a Bayer color array, the SD14 uses a Foveon X3 sensor. Also peculiar is the fact that the infrared filter is on the lens mount and doubles as a dust protector, sealing the mirror and sensor compartment, and can be removed easily, to allow infrared photography. ==Lenses and focusing== The camera uses the SA mount, for which only Sigma itself manufactures lenses. Physically, the SA mount is identical to the PK mount with a reduced back-focus of 44.0mm (equals Canon EOS) as opposed to the 45.5mm of Pentax PK and M42. The Sigma SA lens protocol is a clone of the Canon EF protocol. This provides a not so obvious but very interesting option that most Canon EF-mount lenses will work seamlessly after exchanging the mount plate with the Sigma DSLRs, but without image stabilization. Pentax K-mount lenses physically fit, but should only be mounted when the rear protrusions have been dismantled. Such lenses will then focus beyond infinity and may contact the protective filter. A spacer ring (made e.g. of decopperized FR3 1.5mm circuit board) can be added between the K-mount lens body and its bayonet plate. Prime (as opposed to zoom) lenses often permit a simple resetting of the position of the focusing ring on helical inside. Zoom lenses converted this way will become vari-focals by losing the focus setting as they are zoomed. The spring that opens or closes the lens iris in the K-mount lenses may have to be reset to work in the opposite direction. Although the Nikon F-mount back-focus at 46.5mm is well above the 44mm of the SD14, there is no adapter for the infinity focusing possible as, unlike with Canon EOS, the Nikon bayonet of roughly the same diameter will not fit inside the SA–PK bayonet. The M42 thread does, as taken care of by Asahi when introducing K mount in the 1970s, and therefore all M42 lenses work as is without problems with the SA/M42 converter. Lenses with equal or shorter back-focus (pre-EOS Canon, Minolta, Konica, Miranda) can only be adapted by discarding the old bayonet, milling off extra metal from the lens barrel and adding an SA = PK bayonet flange. Due to the good quality viewfinder (for a crop-DSLR) of the SD14 the missing auto-iris is not a problem, and primes from 45mm up focus comfortably on the screen down to f/5.6. The camera meters automatically via the AV setting with anything mounted on it or being mounted on, such a microscope or a telescope. For this, the camera should be set to a virtual aperture of 1.0. The SD14's solid construction and decent size make it a desirable platform for laboratory and technical photography. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Sigma SD14」の詳細全文を読む スポンサード リンク
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