Few cameras are announced a full two years before they hit the shelves in your local camera shop. But the Sigma DP1 was destined for a long and difficult birth.

Very few compact cameras, apart from Leica's M8 and Epson's R-D1, have taken a large image sensor and squeezed it into a compact body.

The most eagerly anticipated compact camera

Heat, battery and miniaturisation issue are only half the problem; the other stumbling block is the perceived lack of demand for a high-end compact camera that's priced on a par with a DSLR.

Perhaps the low potential sales of such a concept have reduced the amount of R&D dollars companies are willing to invest in such a camera. These problems, along with the use of an innovative image sensor, in part explain the reason for the DP1's delay.

Sigma has gone out on a bit of a limb to produce the DP1 because it could be an expensive flop. For starters, it uses the quirky Foveon X3 sensor, a Direct Image chip that uses red, green and blue photosites rather than the conventional monochrome type overlaid with a bayer filter of coloured dyes.

The Foveon offers stunning colour reproduction without any of the guesswork required with traditional sensors where colour is guesstimated. The absence of a bayer filter does make the images look sharp and the dynamic range produced by the chip is awesome.

Impressive pixel count

Strictly speaking, the megapixel count of the DP1 is an unimpressive 4.6MP, but multiply that by the three colours and you arrive at a figure of around 14MP.

There's no way that the DP1 offers a resolution of a conventional 14MP sensor but it's plenty good enough for A3 prints or A4 with plenty of cropping - and you'll probably need to crop because the DP1 has a fixed 28mm lens with a maximum aperture of f/4.

Add in a fairly basic set of functions and you have a camera that's been designed to appeal to the budding Henri Cartier-Bressons of this world who want DSLR image quality but in a very compact form.

Naturally you'd expect a camera that costs almost ÂŁ600 to be well built -and it is. All the DP1's switchgear is of high quality but the body could definitely benefit from a rubber grip for a more ergonomic hold.

Also, the screen can be very difficult to see properly in bright daylight situations, so it's just as well that a clip-on viewfinder is available.

Sleek and solid

Because the DP1 uses a fixed wide-angle lens, it's not especially good for portraiture or macro photography and is perhaps more suited to landscape work, reportage and interior shots.

The autofocus isn't as snappy as the type of mechanisms used in DSLRs, but once the shutter's been depressed halfway, the response of the camera is acceptable, although you may miss some critical action shots.

On the DP1's top-plate is a power switch, a shutter release button and a mode dial that offers P, A, S, M modes as well as video, sound recording and a fully automatic setting. A small and rather underpowered flash pops up stylishly from the top-plate and smacks a little of Leica.

To the back of the DP1 there's a 2.5-inch LCD screen with 230,000 pixels, and next to that a small navipad is used to navigate around the menus. Apart from this Spartan collection of controls, the DP1 is clean, sleek and solid.

In addition to the basic bundle of the DP1 and the hotshoe-mounted optical viewfinder, Sigma is also selling a lens hood and filter holder kit and a TTL mini flashgun to replace the rather puny built-in unit.

For gadget and function freaks, there's no image stabilisation or face detection, but for serious photographers that's probably not a drawback.

Hit and miss performance

So how does the DP1 perform? Well, to be honest there's a noticeable shutter lag that can really get in the way when you're taking quick-action shots.

Not only that, but the metering can be a bit hit-or-miss - you may well end up getting frustrated and switching over to manual metering for more consistent results.

As far as image quality goes, there's something very special about the Foveon X3 sensor... so long as you shoot in RAW mode and use Sigma's own Photo Pro RAW converter. The DP1's images have an analogue quality that really does seem to bring colour to life.

Even the noise levels are good. In our tests we were very happy with noise at ISO 400 and even ISO 800 was more than acceptable. We did find that the dynamic range was excellent and there was no sign of chromatic aberration, thanks to the fixed 28mm lens.