It's rare these days to get a camera into the office that has the potential to be something really different. Sure new models come out with improved megapixel counts and better feature sets, but for the most part the basic technologies don't change. Enter Sigma's latest SLR, the SD14. The only SLR manufacturer to use the new Foveon X3 sensor, Sigma has eschewed the typical CCD and CMOS sensors for something a little different. While it does pay off in some regards, in other areas the SD14 is clearly behind the competition and considering the cost there may be better options elsewhere.

The Foveon X3 sensor is the key attraction of the SD14. A typical CCD uses filters to direct the appropriate colour to the appropriate pixel; however, the Foveon operates differently. It is constructed of silicon and works on the principle that different colours will be absorbed at slightly different levels within the sensor. Thus there are three separate levels of pixels, one for each colour. In theory, this allows for much brighter, more vivid hues and better detail in colourful areas.

We typically test using a combination of test shots and our Imatest software, unfortunately we found that Imatest was largely unsuitable to properly evaluate this model as its strengths and weakness are so distant from conventional CCD-based SLRs. The sensor is quoted at 14.1 megapixels, but due to its design, it is difficult to compare directly to other models.

Sigma has acknowledged that the SD14 won't perform as well as competing SLRs when rendered black and white subjects, however its colour performance should be much sharper. In our test shots we found this was the case to some degree, although there was a little softness evident even in high colour areas. Chromatic aberration was minimal, with no haloing in high contrast areas or blurring towards the corners of the frame while purple fringing was kept under control. We'd still give the edge in terms of sharpness to the new crop of 10-megapixel models from Canon and Nikon, regardless the SD14 is a reasonable performer.

Where the SD14 really shines is in colour reproduction. If you're looking for bright, strongly saturated hues then this model may be right up your alley. Everything looked extremely vivid, particularly in some of our outdoor shots. We'd almost go so far as to say our shots were over saturated on occasion, but a little software tweaking should help remedy that.

Noise performance was a mixed bag. At ISO 100 our shots were clean and smooth; however, as we ramped the sensitivity up, the images took a turn for the worse. SLRs typically can shoot up to at least ISO 800 without many issues and sometimes higher, but the SD14 is probably best kept at ISO 400 or below.

In our speed tests it performed reasonably well, starting up in 1.8 seconds and taking just half a second between shots. The burst mode operated at a healthy four frames per second. However, operating times were a little sluggish, with the unit often pausing between basic functions such as navigating the menu and deleting pictures.

Features wise this is a fairly standard affair. For the first time Sigma are offering JPEG shooting in addition to RAW which has been a long time coming. White balance presets and custom mode are on offer, but disappointingly you can't adjust by kelvins. ISO sensitivities extend to 800 by default although ISO 1600 can be accessed via the menu.

Unfortunately the control scheme is a little irritating. There is a shortcut key that brings up ISO, white balance, image quality and format options, but they can only be adjusted in one direction using the D-pad, so if you want ISO 400 and accidentally skip past it, you have to cycle through all the options again to get back there. Similarly, if you want to alter other settings like metering and auto focus mode, you use the function button, but it requires a complex combination of button presses and button holds to achieve the desired result. You can wind up hitting the key seven or eight times to make a single change, and if you accidentally release it at the wrong time you have to start from scratch.

The body is constructed of a combination of rubber and stainless steel and feels extremely sturdy. Meanwhile the 2.5in LCD display only has 150,000 pixels and thus doesn't render preview images as well as some competing units.