Sigma SD14 review

Independent lens maker Sigma is well known for its wide range of affordable film and digital optics that fit all the popular makes of DSLRs, but the company also manufactures its own DSLR with the exclusive, triple-layer Foveon X3 sensor.

Sigma's SD14 is the successor to the SD10, featuring 14-million photodiodes, an improved viewfinder, a larger 2.5in screen, extended ISO1600 maximum and, unusually for Sigma at least, both in-camera Jpeg and Raw file capture. While the headline features bring the SD14 into line with rival offerings, the Foveon sensor's potential for resolving finer detail in colour images over conventional imaging chips remains the main attraction.

Unlike other sensors the Foveon X3 chip has three photodiodes per pixel location, but they're aligned in three layers of silicon consisting of 2652 x 1768 photodiodes per layer. This unique stacking structure allows the camera to capture full-colour data in all three primary colours at each pixel location, so it maintains colour accuracy without sacrificing detail. We've no real concerns with the sensor technology.

Before the advent of digital, Sigma made affordable 35mm SLRs, so how does the SD14 compare with semi-pro rivals from established camera makers?

Improvements in handling over the earlier SD10 are instantly noticeable. The camera starts briskly and feels reasonably responsive. The archaic sports-finder has been replaced by a purpose made viewfinder, although it seems a little cramped compared with the Nikon D200's.

The build quality is similar too; it's well made but lacks weatherproofing and its case is not up to the same standard as the metal shells of either the Canon EOS 30D or the D200. Neither were we that impressed by the 5-point AF system. Compared with rivals and even some entry-level digital SLRs, it's easily outclassed in focus accuracy and speed of operation.

The SD14's lens mount takes only Sigma (SA) mount lense, and thanks to the 20.7mm x 13.8mm (roughly APS-C sized) sensor, effectively crops the lens' field of view by 1.7x. Although there are no officially bundled lens options, the smaller sensor makes the popular Sigma 17-70mm f/2.8-4.5 DC Macro, for example, become a handy 29-119mm in effect.

While having a choice of interchangeable lenses is a major plus for any DSLR, the possibility of dust entering the body and settling on the image sensor is only too real. Although it lacks automated sensor cleaning as seen in the Olympus E-series cameras and the Canon EOS 400D, the new Sigma, like the earlier SD10, features an easily cleaned removable optical filter that seals off the body behind the lens.

At the rear is a reasonably clear and detailed 2.5in screen and, thankfully, a top-plate info panel, although the data it displays is not as informative as we would like. With the exception of the command dial that surrounds the shutter-release the controls are generally well-placed, but selecting file types and image size can be a hassle.

As well as the usual quality settings for in-camera Jpegs you'll also find the proprietary Raw file option at the native 2640 x 1760 pixels. Switch back to Jpeg capture, though, and unless you select a SuperHi resolution option of 4608 x 3072 pixels (14.1 MP), you'll be left with Jpegs the equivalent of just 2640 x 1760 pixels (4.6MP) if you forget. In-camera Jpegs are extremely high quality, even with the interpolated SuperHi resolution option, but file sizes are hefty at 7.5MB. Continuous shooting suffers as a result - the 3fps maximum is behind most except the Fuji S5 Pro, and buffering just six Raw or best-quality Jpegs is poor at this level.