|1. The SD1 includes a rugged magnesium-alloy body design that's built to be lightweight and also effective when shooting in rougher environments. The SD1 is the first camera from Sigma to include a splashproof design. 2. Many cameras in this class don't offer a built-in flash. The SD1 includes a GN 11 pop-up flash and a hot-shoe for adding a more powerful dedicated flash. Sigma currently offers three external flashes with a maximum sync shutter speed of 1⁄180 sec. 3. With an approximate 1.5x crop factor in 35mm equivalence, the Sigma SA bayonet mount is compatible with more than 50 of Sigma's versatile SA-mount interchangeable lenses.
LIST PRICE: $6,899 (body only)
With an incredible 46 megapixels on an APS-C-sized sensor, the Foveon X3 image sensor of the Sigma SD1 is its most talked about feature. The sensor is able to achieve such a high resolution through Sigma's unique Foveon design (Sigma purchased Foveon in 2008), which bypasses the traditional Bayer pattern of light-sensitive photodiodes that capture a blend of red, green and blue primary color information.
Instead, the Foveon sensor sandwiches three separate layers of red, green and blue photodiodes on a 23.5x15.7mm sensor. With 4800x3200 pixels, numerically this translates to roughly 15.36 megapixels in three layers, or 3x15.36, which works out to approximately 46 megapixels of effective information.
The Foveon design potentially offers more specific color information and better results with moiré, the zebra-like color-
pattern distortion that you'll see on certain fine patterns in an image like stripes and lines. Other cameras employ a low-pass or anti-aliasing filter to reduce moiré, which also reduces sharpness at the capture level.
With a 5 fps continuous shooting speed in high quality and a 6 fps maximum speed in medium and low, the SD1's brand-new TRUE (Three-layer Responsive Ultimate Engine) II image processor is responsible for powering such large-resolution image capture at relatively fast speeds.
STANDOUT FEATURE: The 46-megapixel APS-C Foveon X3 sensor brings the SD1 into the class of über-expensive medium-format cameras from Hasselblad, Mamiya and Phase One, only at a price point that's roughly a fifth of these professional systems.