When I first fiddled with the DP2, I was like "Who would ever want this?" Then I shot some of the most amazing photos I've ever taken.
The Set Up: Sigma calls this camera a DSLR in the body of a point and shoot, and they're kinda right. It's got the Foveon X3 sensor, which is just a hair smaller than the Nikon and Canon APS-C sensors. Sigma has carefully paired a fixed 24.2mm F2.8 lens in order, they told me, to maximise the benefits of that larger sensor. No zoom lens would do, they said, because picture quality would likely suffer.
To make things even more complicated, for these same reasons, they could only build in contrast-based autofocus. Though more accurate, it takes a lot longer to focus, and, in this camera, tends to give up easily when it can't quite do it. It was often hard to get a satisfied chirp that meant focus was locked, especially in lower light conditions. Many hastily shot shots are blurry beyond help.
As you can see, this camera is low in the frills department, with greater reward going to those who can shoot manually, and most certainly in RAW. Meaning my first shots were hideous things, and it took a few days for me to become worthy enough to even hold the bastard. Eventually, slowly, I learned what it could—and could not—do.
The Bad News: Let's repeat: There's just the one fixed lens, which isn't much of a wide angle, isn't much of a macro, isn't exactly "fast" by today's DSLR standards, and does not zoom. You have to get in the habit of going to your subjects, then making them stay still long enough to get a decent focus, then a decent shot. To add to the troubles, the sensor that is pristine at ISO 200 is noisy as crap at ISO 800, which means you also have to shoot longer at times to make up for it.
Sigma people said that the ISO should be compared to other point-and-shoots, and that shooting RAW and converting it to JPEG on the computer cuts down on the noise, but even so, check out how crazy the noise was at 1600 after RAW post-processing on the computer:
It's a mess, you know? I did manage to make some artistic looking black-and-whites by just desaturating the grainy 1600 shots—frankly, they were pretty cool, but it's something you'd want the option to do, not something you should be forced into.
Other dings the camera gets are a lack of RAW+JPEG mode—what I like to call "insurance+good enough"—some extremely abysmal QVGA video mode that probably should have been left out of the product altogether because it's pointless, and poor battery life. When Sigma sent me the camera, they included a spare battery. I thought it odd at the time given how insanely great camera battery life is these days usually. Clearly they knew something I didn't. On top of all that, it's just not terrifically small—Olympus and Panasonic are pushing Micro Four Thirds cameras that aren't much bigger. (Course, their sensors are actually smaller.)
The Good News: As I have alluded, I have come around on this camera. Push aside all of the uncool characteristics, focus on what it can do—shooting relatively still objects at relatively close range—and you get some seriously attractive photo work. I can't show them all to you—the wife lays down a general rule of not posting family pics in Giz reviews—but what I can show you should give you a decent idea of the DP2's capabilities, coupled with patience and some basic know-how, can.
The Rub: As much as I'd like to say it's a great camera for photographically inclined people to stash somewhere for certain situations, it's too damn expensive. It costs around $US650 street price; for that money you can probably get a clearance-model DSLR model these days, maybe even with a kit lens. In the end, I've come to think of the Sigma DP2 as the Dogfish Head 120 Minute IPA of cameras: Beautiful in concept but complex, powerful and damn expensive—if you hit it everyday, it could well get the best of you. [Sigma]
For a small-bodied camera, it has exceptional picture-taking capability and superior image quality
Its $US650 cost can only be justified by a small percentage of wealthy photo enthusiasts
It's tricky to use at first
Crap battery life
No zoom lens or any other obvious point-and-shoot frills