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.