Sigma DP1 Review

Sigma’s potentially ground-breaking DP1 was first announced in 2006 and is the first “pocketable” compact to feature a large APS-C sized sensor. The DP1 is all about image quality potentially rivaling some DSLRs, but can it live up to the billing?

Sigma created a storm with the announcement of the DP1 back in 2006. It held out the promise of DSLR image quality from a pocketable digital compact and the DP1 is all about pure image quality.

The offer of this possible digital compact photo nirvana is held out to us courtesy of Foveon’s controversial X3 CMOS sensor technology. For those not in the know, the Foveon X3 sensor differs from most sensor technology in that, rather than having a Bayer colour filter with a matrix of red, green and blue squares, from which the otherwise colourblind sensor “demosaics” the colour information in the image, the X3 can record all three red, green and blue colours at each pixel location.

The DP1’s sensor is enormous compared to sensors found on other similar compacts, such as Canon’s G9 or the Ricoh GX100. Both those cameras use a sensor with a diagonal of around 10mm.

The DP1’s sensor is 20.7x13.8mm and is essentially the same sensor as that found in Sigma’s SD14 DSLR and so offers an diagonal of around 28mm.

Factor in the way the X3’s photosites are buried within the CMOS’s silicone (light of varying colours can only penetrate to certain depths and that’s how you can capture all three colours at each pixel location) and colour fidelity is dramatic.

Sigma aside, only Panasonic’s new Lumix LX3, which uses large photosites to help get great images (the full test of which will be coming in a week or two, so watch this space) has changed the way sensors “do things” recently. But it’s a bit of puzzle since confusion reigns over the actual pixel dimension measurement.

Because the pixels are together, the actual image dimensions provided by the DP1 are 2652x1768-pixels so that’s 4.6-megapixels. Sigma (and Foveon) then multiply that figure by the three colours (red, green and blue) but even then, the actual image dimensions look modest when compared with the latest 10 or 12-megapixel Bayer cameras out there.

Nonetheless, the X3’s photosites are big so noise issues are simply not an issue, until you get the top ISO800 setting. Also, the amount of detail captured thanks to the fixed, 28mm wide-angle lens gives the apparent resolution of a camera with a third more pixels; akin, in fact, to a camera with around 8-megapixels by my tests.

Yes, the final image file size is smaller, but modest resizing using Photoshop can easily push the photos to a size that will print at 19x13-inches without much of a problem. They’re cleaner, sharper, and more colourful than equivalent Bayer sensor shots too.

The DP1 is in fact a dramatic illustration that it’s not always the number of pixels that help make a great shot (or better camera) but the size of the pixels themselves and their density on a sensor. The DP1 can shoot both JPEG and RAW files, but shooting JPEG means you’ll loose the benefits of the big X3 sensor, so leave JPEG well alone and you’ll be very happy with the picture quality indeed.

The supplied Sigma Photo Pro software is easy to use but very slow and clunky, plus, the Foveon X3F RAW files are still not widely supported by other, less cumbersome RAW processing packages such as Lightroom, so bear this in mind. Without a doubt though, other RAW software packages will inevitably support it in time.

In terms of handling and performance, the camera is a little larger than you’d think but not horribly so. The boxy shape provides little to hang on to, but the metal construction is tough enough.

The lens protrudes from the body when you switch the camera on, despite it not being a zoom and there’s detachable lens hood to help shade the thing from stray off-axis light. It's worth using to ensure you get the best contrast and minimal flare in your photos.

A minimal set of buttons include a large top plate mode dial for the P, A, S and M settings along with auto and a crude 320x240-pixel movie setting. “Zoom” buttons on the back activate the digital zoom (yep, you guessed it, leave that alone) or are otherwise to be used for magnifying images in playback.

Manual focus is achieved via a small, freely rotating dial that ideally should have ratchet stops; it’s just too easy to knock out of focus once you’ve set it up.

There’s exposure compensation and this needs to be used more often than I’d hoped, as the metering system seems a little temperamental. But, as can be said for both this camera (and its software), patience is the key.

Writing a single RAW frame you’ve just shot can take (gulp!) 7-seconds, though you can shoot three JPEG or RAWs in continuous mode before it locks up for a frustrating 15-seconds or so. The DP1 demands a steady approach to shooting and should not be rushed – and adjusting the way you shoot is takes a little time.

All the key settings and features are buried in menus that are pretty much a disaster for a modern digital camera. There are no “hard” buttons to any key settings, the colour screen is murky too, and unless you have it set to its brightest mode, it’s hard to see even if it is not very bright. Battery life suffers as a result too I’m afraid.

An accessory optical VF-11 viewfinder slots into the flash hot shoe and is an advisable purchase, as it will help get more from the camera’s battery. However, the limited AF system (you can only use one AF point of the nine available at a time) needs care as the narrow depth of field afforded by that bigger, APS-C sensor, means focusing is critical in close up, or for more complex subjects at larger apertures.

And so, the DP1 is a camera that harks back to the days of yore in terms of control and accessing key settings and, to a degree, even its gross resolution. Think 2002 digicam technology and you’ll know what I mean. Even more importantly, the DP1 is very expensive at £550.

That’s more than most budget DSLRs with a kit lens and with comparable sized sensors!

The Sigma DP1 is therefore a bit of a mixed bag. Thought of as a quality compact digital camera, the image quality is streets ahead of any of compact with a “normal” sensor and competes well with DSLR image quality making it a realistic back up.

But the issues around poor menu design and the handling foibles make it a frustrating experience both when snapping and when processing on PC later, using the Sigma Photo Pro software.

If you’re going to use this camera tripod mounted, for more studied work, or as an occasional quality snapper, it’ll serve you well. But if you need something a bit more lively as regards performance then it won’t be for you, and there's no getting around that high-ish price tag either.