Sigma DP2 Merrill review

Features

As with the Sigma SD1 Merrill DSLR, the company claims the DP2 Merrill ‘realises medium-format image capability'. With a 44.3-million-pixel resolution, such claims are, on the surface, believable. What needs to be understood, however, is that all the cameras in the Merrill series feature Sigma's own unique Foveon X3 sensor. This sensor has separate red, green and blue layers of photoreceptors, each with 14.8 million ‘spatial' pixels that, when combined, total approximately 44.3 million pixels, not the quoted 46-million-pixel count.

An imaging sensor such as this, which processes each colour light wave in turn rather than combining neighbouring pixels, should in theory give superior colour rendition. However, it also means that light is filtered three times, reducing its brightness and potentially introducing noise. I will explain this in greater detail in the Noise, resolution and sensitivity section. The sensor in use here is an APS-C-format unit, which is impressive for a camera of this size and price.

Like Sigma's DP1 and DP2 compact cameras, the DP2 Merrill features a fixed-focal-length lens, in this case a 30mm f/2.8 (approximately 45mm f/4 on full frame). This means the lens is ideal for most types of photography, particularly portraits and landscapes. The lens is constructed of eight elements in six groups, and by including one aspherical element and three high-refraction elements, the company claims it has been able to achieve excellent image quality in a compact unit.

The camera comes supplied with Sigma Photo Pro, the company's own raw-processing package. At the time of writing, the X3F raw files are not compatible with software such as Adobe Lightroom, so the files in this test have been processed using the frustratingly slow Sigma software.

Beyond the core of the camera, there is little to write about. This is not a camera for those who want a number of shooting modes and picture effects, but one designed to please photography ‘purists'. The processing power of the camera is not sufficient enough for anything beyond a five-frame raw & JPEG burst, with the files taking just under a minute to be processed.