The Sigma SD14 is unique. It is currently the only camera that uses a 14-megapixel Foveon X3 Direct Image CMOS sensor, which operates on a different principle to the Bayer-mask mosaic sensors used by every other digital camera on the market. It isn’t the first one to do so, since the two previous Sigma digital SLRs, the SD9 and SD10, used earlier smaller versions of the X3 sensor, but since those cameras are no longer in production the SD14 is the only model available that uses this innovative technology. For a brief explanation of the Foveon sensor and how it differs from a conventional CCD or CMOS sensor see this tutorial which I wrote a few months ago.
The main advantage of the Foveon sensor is that it detects all colours at every pixel location on the sensor, whereas conventional sensors can only detect either red, green or blue at any one location, with the full-colour image being interpolated from the combined signals of several individual sensors. In theory the Foveon X3 sensor is capable of producing sharper pictures, more accurate colour rendition and superior dynamic range. We’ll come back to this in a while, but first let’s take a look at the camera itself.
The SD14 is not a cheap camera. It costs around £799 body only, which is about the same price as a Nikon D200, and £200 more than the Canon EOS 30D. Add the superb Sigma 18-50mm F2.8 EX DC which arrived with my review camera and you’re looking at around £1,100, which is a lot of money to spend when there are several very good DSLRs on the market for under £500.
The initial impression of the SD14 is that this is a big, heavy camera. Admittedly I’ve been a little spoiled by the lightweight Olympus E-series DSLRs I’ve been using recently, but by any standards the SD14 is a substantial piece of kit. It measures 144 X 107.3 X 80.5mm and weighs 750g including the battery, which is about the same size and weight as semi-pro cameras such as the Canon EOS 30D or the Pentax K10D, and much larger and heavier than any of the 10-megapixel mid-range or entry-level cameras such as the Sony A100, Nikon D40x or Canon EOS 400D. It is a bit smaller and lighter than the D200 though. Fortunately that size and weight translates into solid construction and excellent build quality. The body is high-density plastic over a metal chassis, but it is very well made with close tolerance on all joints and control mountings. Sigma has been making some of the best third-party lenses in the world for over 40 years, and that experience shows in the construction of the SD14.