And thus it came to pass that...
in March 2018 I bought a new camera. It's a model I've had my eye on for some time - I was intrigued not only by the way it looks but mainly with the claims made for it. Having downloaded numerous samples from the interwebs, and studying them, finally I decided, yep, that's for me. so may I introduce you to:

The Sigma dp0 Quattro

The Sigma dp0 Quattro is one of four near-identical cameras from Sigma, differing only in the focal length of the fixed lens mounted on each model. The dp0 has a 14mm lens, the dp1 has 19mm, the dp2 has 30mm and the dp3 has a 50mm. In terms of actual 35mm camera equivalents these equate to 21mm, 28mm, 45mm and 75mm, so, as you can see, two wide angles, one roughly standard, and one modestly telephoto. Other than the lenses, the four cameras may be considered to be identical, and therefore much of what I say here can apply to all four models.

Nobody will deny that these cameras look, shall we say, wacky, and there’s nothing else out there that looks anything like them. They’re wide, yet quite thin, with a pronounced hand grip, and the lens is off-centre.

In a May 2018 update, I'm pleased to say that I've been so impressed with the ultra-wide dp0, that I've now added the standard focal length (45mm equivalent) dp2 to my Sigma family. Utterly delighted, and every bit as stunningly sharp as the dp0. Everything I say below applies equally to both cameras.

The unique factor about these (and other) Sigma cameras is their light sensor, best explained by Sigma themselves:

Leveraging the light absorption characteristics of silicon, the sensor comprises three layers of photodiodes, each at a different depth within the silicon and each corresponding to a different RGB color. Since it is the only sensor to use this superior vertical color separation technology, it is also the world’s only direct image sensor. The Foveon direct image sensor captures color vertically, recording hue, value, and chroma accurately and completely for each pixel, enabling the expression of rich gradation and tone. Moreover, there is no low-pass filter needed to correct the interference caused by a color filter array, unlike the data from other sensors, which requires artificial interpolation to “fill in” missing colors. The data from the Foveon direct image sensor is complete with light and color information for every single pixel.

The SIGMA dp0 Quattro incorporates a newly developed Foveon X3 direct image sensor (generation name: “Quattro”). The new sensor structure features a pixel ratio of 1:1:4 from the bottom, middle to top layer. The Foveon X3 Quattro direct image sensor is able to detect a broad range of light wavelengths. While the top layer captures both brightness and color information, the middle and bottom layers with their larger surface area capture color information only. During the image data processing stage, the brightness data captured in the top layer is applied to the top, middle, and bottom layers, resulting in brightness and color data for each individual pixel. Retaining the principle of the three-layer structure where colors are divided vertically, by applying the brightness data captured in the top layer to the layers below, high resolution and high-speed for broad data processing required are achieved.

Now, the Foveon splits the world of photography; many many afficionados of the shutter click hate the Foveon. They don’t agree with Sigma’s claimed quality or megapixel counts, which, in some cases are 3 times the actual size of the image produced. I have to agree with that point. A 20 megapixel picture is 20 megapixels. But those who like Sigma cameras and their unique sensors will defend them to the death.

But, sensor aside, let’s look at the dp series. As the pictures show, it looks funny! Is it weird or dramatic? Up to you. But it’s solid and its weight is just right. That big lens has a silky smooth focussing ring, for those who like to go manual, and, while it doesn’t have very many buttons, it does have two control wheels atop its body, which are multi-purpose, depending whereabouts you are in the menu system. The latter, incidentally, is fine, clear and easy to navigate, either by clicking up and down the choices or by use of the control wheels.

The Good Points
Absolutely, undoubtedly and inarguably: picture quality. The 19.6 megapixel results are stunningly clear and sharp, a match for most other cameras out there, and either on a par with, or exceeding, the quality of the results from my Pentax K-1 full frame 36 megapixel monster. I always shoot RAW (which I discuss from the Sigma point of view below) but I’ve been finding that Pentax RAWs always seem to need more adjusting and general fiddling-with to get the right JPG than do the Sigma’s RAWs. See my What Others Say section below if you don’t believe me!

It’s easy to hold and use, and with the irritating beeps switched off is as near to silent as you can get. It doesn’t feature any form of in-body or in-lens stabilisation, but the camera is so light, and the shutter button so effortless that you’d be very unlucky to witness any camera shake.

There’s the option of a horizon leveller in the viewscreen, to make sure all your pics are level. I’m guilty of many wonky pics and so I find it’s very useful to watch for those two little bars turning green, indicating levelness, before clicking.

It comes with two batteries - unique, I’m sure, in the camera world.

I don’t seem to include many good points here, but please don't feel that this isn't a "good" camera because of that, as I consider that picture quality is our ultimate goal, along with ease of use, and the dp series offers these more than adequately. I do unfortunately feel the need to highlight …..

The Bad Points
A small but troublesome matter to start with, but it was the first thing that crossed my mind when I unboxed it: where the hell do I put my right thumb when holding it? As you see in my pictures, about 50% of the buttons are right there in thumbland. The biggest culprit here, and the one most likely to be thumbed is the one marked Focus (the top quadrant of the square multi-way button you can see in one of the pictures). One inadvertent press on this and bang, you’re in manual focus mode, and the only indication of this is a tiny label which appears on the screen. You could, therefore, quite easily ruin numerous shots, all out of focus. This scenario is less important with the wider angle dp models, with their greater depth of field, but could be a major issue with the dp3 and 4. In time, with practice, you’ll learn where to put your thumb, but I suggest you also learn to look frequently for that MF label. Alternatively switch on the little beep that announce "I'm in focus".

I mentioned under Good Points that it comes with two batteries - a good thing, because battery life is not great. You’ll be lucky to get 200 pics out of a full battery.

Manufacturers spend billions getting their cameras just perfect, and then sell it to you with a nasty neck strap, and Sigma is no exception. Ditch it ASAP and spend a few pennies on replacing it.

A conceivably and arguably bad point is the file format. A separate section for this follows below.

A month later and a bad point emerges: I was out photographing the other day. It was a bright and very hot day when suddenly I noticed that the images in the view screen seemed awful bright. Switching the camera off and back on reverted things to normal. On examination of the affected pictures back home they were indeed very very overexposed - by about 2.5 stops as near as I can tell. They weren't totally ruined as I was able to get something back in LightRoom, but it's a little problem that needs to be watched.  Update a few days later: it seems that this overexposure only occurs when using spot-metering. Use center-weighted or evaluative and there's no problem.

Minor Niggles
I'm not going to classify the following as Bad Points, because they are not bad, just slightly negative.

The first is noise and ISO. My Pentax K-1 is very excellent in this regard, and on dull days, of which we get so many here in the UK, I can quite happily dial in ISO 800 and get essentially noiseless pictures. Dial in ISO 800 on the Sigma and you'll be tempted to run down the street in fear when you see the results. Anything above ISO 125 and you'll start seeing noise, it's as simple as that. The reason this isn't a bad point, just a niggle, is that using ISO 100, with its implied slow shutter speeds, makes you a more gentle, more thoughtful photographer. No quickly grabbing the camera and quickly snapping sonething; no, every shot has to be thought about and carefully taken, because the shutter speed might be 1/30 or longer. But this thoughtful approach, combined with the design and feel of the camera, means that you could find yourself out there, perhaps in a shady graveyard, taking successful pictures even down at 1/8 of a second. I know - I have the proof. I find that in 'P' - program - mode, where the camera decides upon both aperture and shutter speed, it tries its best to give you a good aperture, perhaps at the expense of shutter speed. That last statement really qualifies as an anti-niggle, even a Good Point.

The second mini-niggle is colour rendition, and this is so mini-minor that it hardly qualifies to be included, but I'll state it anyway: the pictures can be just a trifle under-saturated in the green department and sometimes a little overpowering in the oranges. But it takes perhaps 17 milliseconds in LightRoom to correct those!

The third and final minor niggle concerns exposure in general (but of course your own mileage may vary on this point). Too bright. At standard exposure I find that all my pics need dialling down a bit in the exposure department. Therefore I routinely shoot at -1/3 of a stop.

The File Format
As stated, I always shoot RAW. Not only because I enjoy sitting in front of the computer dicking about with the pics, but because one rarely agrees with what the manufacturer considers to be a good out of camera JPG. Their JPGs are either under- or over-sharpened, over- or under-saturated, too cold, too warm, etc, etc. No; give me the untouched photons splashed straight from the sensor into the RAW file and let ME make all the decisions.

But. Sigma. X3F. A wacky, though 14-bit (most others are 12), uniquely constructed RAW file. LightRoom, Camera Raw, Capture One, Affinity, OnOne: all fine RAW development packages, yet not a one will open an X3F. Sigma offers the rather optimistically entitled Sigma Photo Pro as a free RAW development tool. It’s not the best RAW software in the world, by any means, but SPP, as we know it, is effectively the only software which will open an X3F; SilkyPix also will, but, in my humble opinion, it’s unuseable. Complex, difficult, and entirely obfuscated with many adjustments which either do too much or nothing, or are called the wrong thing. Silky is very easily and pleasingly uninstalled about an hour after you started your trial. SPP is pretty slow, but hey, if you went out yesterday and took 50 pics, sitting down for a pleasant hour of post-processing is hardly going to harm you, BUT.... you might not do your post-processing in SPP, merely use it as a go-between, a mid-process tool. Read on.

I’m a firm believer in Capture One. It’s what I’ve used for years (I’ve written about it in a lateral way on this site). I use a Tangent Ripple control surface with COne, and the combination is perfect. But it won’t open an X3F. Capture One has been relegated to being my Pentax RAW tool only.

Fortunately, possibly as an answer to what may have been an infinite number of complaints about X3F and SPP, and possibly due to their inability to write decent RAW software, Sigma saw the light and now offer DNG as an option. DNG is universal. Anything will open a DNG, including COne. BUT, and it's a big but, DNG, though apparently convenient, is probably not your best option with a Sigma X3F. So, while X3F is the funny old uncle, slightly daft, a bit smelly, that everybody tries to ignore at family get-togethers, because nobody can really understand what on earth he’s talking about, it’s undoubtedly the best for X3F - read on.

I’ve done a great deal of research into the X3F phenomenon. While there’s a few who are happy enough to sit in the corner with the daft uncle, many have sought alternatives. As I say, the simplest option is simply to set the camera into DNG mode and start clicking. But there seems to be a common thread of dp users who go to tortuous lengths with their X3Fs, and one route seems to be to shoot in X3F, import them into SPP, don’t do any adjustments there, but simply export them as 8 or 16 bit TIFFs, and then proceed with them to PhotoShop or whatever to do all the adjustments. As a further comment, I am convinced that DNGs out of the camera are not as 'good', for want of a better word, as X3Fs. This niggling feeling was reinforced the other day when, after a good session in sunny weather, I found the resulting DNGs to be really and inexplicably noisy. The following day, an X3F session gave me clean and noiseless pics. Go figure.

So after hours, literally, of trying all the various routes I’ve made my decision. I know how the future of my Sigma dp0 RAW processing looks.

But one last question I’m sure you’re asking: which is best, notwithstanding my personal view? The options, summarised:

  1. Shoot X3F, develop to JPG in SPP
  2. Shoot X3F, develop to JPG in SilkyPix
  3. Shoot X3F, export as TIFF via SPP then into CaptureOne or Lightroom, or any other software you think of or have
  4. Shoot DNG, develop in whatever software you like best

At this moment, having spent hours and cross-compared so many results to the extent I’m cross-eyed, I’m voting for number 3. Number 1 is just not on: SPP doesn't have the wherewithals to deliver JPGs easily, nicely, or to taste. As for number 2, forget it (in my humble opinion.) Silky Pix is horrible. So from this day forward: shoot X3F, export them to TIFF with SPP, work with the TIFFs in LightRoom. Simple. Besides, I have a Loupedeck, specifically designed to work with LightRoom Classic, and is much better than the Tangent Ripple, to be honest, and I'm really not happy with Capture One's handling of TIFFs.

The X3F/TIFF experience. The flow is to offload the X3Fs from the memory card into a folder. Open SPP and import that folder. Check that every SPP adjustment is zeroed and that you're exporting as originals, ie, unsharpened, unbalanced, untouched, etc. Export to 16-bit TIFF into a different folder. While exporting, get a cup of coffee and a sandwich, because the export takes a while - about 10 pics per minute as near as I can tell. Open LightRoom and import the TIFFs. Now is a good time to review your work, but STOP! Don't panic! These untouched (so far) TIFFs are too bright, undersaturated, and quite cold. If you're into video you might compare them to Cinema RAW clips. But, and now it's an important but, these cold bright horrors are very very amenable to editing, and adjust beautifully in LightRoom. You'll probably start with upping the colour temperature to warm them up a bit, then you'll turn down the exposure, as much as a stop or two, then you might want to up the saturation. These are the three basic twiddles all Sigma TIFFs will need. But then, unlike cameras with Bayer sensors, which inherently produce undersharp pics, you might not sharpen your Sigma pics, you just won't need to. Export a lovely JPG and sit back in awe and wonder.

I love this camera. Wacky and odd to look at, it becomes a pleasure to use once you’ve sorted out the thumb position and decided upon your RAW position, and replace the strap, and the results are simply spectacular - whichever development route you use. You’ll see examples of its output in my Taphophilia albums here, but they’re reduced to 1500 pixels wide.

But what do others say?

I'm including below a few words from a handful of respected sources which I hope will back up my own views on the cameras:

Whilst other compact cameras offer similar wide-angle (or wider) options, none of them offer anywhere near the same high resolution images that the dp0 Quattro offers, making it a somewhat unique and rather quirky camera. The Sigma dp0 Quattro offers an excellent 14mm f/4 (21mm equivalent) ultra-wide angle lens, along with some of the best image quality output from the Sigma dp cameras, with much better white balance performance than previous versions

The Royal Photographic Society:
Images were sharp right into the corners of the frame, with a colour rendition that looked more life-like than the processed images we’re used to seeing from consumer compacts; indeed, Sigma has made much of its Foveon chip’s ability to reveal subtle nuances and shades. Although there is a continuous shooting option, it quickly becomes obvious that the dp0 promotes a careful, considered, contemplative method of image taking. Use this leisurely approach and you’ll feel rewarded

There’s little to complain about in terms of build. The magnesium-alloy body feels solid, and operation is fast and responsive. Chunky twin dials on the top-plate are used to change exposure settings, and the lens has a large, smoothly rotating manual focus ring. When it comes to image quality, there’s really only word to describe the dp0’s output at its best: astonishing. The lens is superb, being stunningly sharp corner-to-corner even at f/4. At ISO 100-200, the camera’s output is very clean and phenomenally detailed.
Sigma's dp Quattro series offers dramatic styling and a fundamental re-think of the company's Foveon multi-layer sensor design. There are four cameras in the dp range, all identical except for their lenses, which have focal lengths of 14mm, 19mm, 30mm and 50mm (that's 21mm, 28mm, 45mm and 75mm equivalent).
Very little about Sigma's Quattro series follows tradition. Each of the four bodies houses a unique, APS-C-sized, Foveon multi-layer sensor that uses three layers to detect color information. It captures a full, 19.6 million pixel resolution image in the top layer, with the lower two layers capturing 4.9MP of information each.
Buyers seeking a unique experience with Foveon sensor technology coupled with radical body styling might find a lot to like about the experience of using the Sigma dp Quattro series.

Amateur Photographer
Let’s get one thing absolutely straight: the Quattro’s image quality at low ISO settings is little short of astonishing. Its lens is simply superb, being sharp from corner to corner with no visible chromatic aberration, even when shot at f/2.8. There’s visible (but not objectionable) vignetting when wide open, which disappears by f/4, and a touch of barrel distortion. Overall, this is one of the best optics I’ve ever seen on a fixed-lens camera.The Foveon X3 Quattro image sensor is in its element at ISO 100-400, delivering incredibly sharp, detailed images that look quite unlike files from conventional Bayer-sensor cameras. The pixel-level detail is extraordinary, aided by that wonderful lens, and the sensor is capable of recording subtle changes of colour and tonality from pixel to pixel. So while the sensor’s native output resolution is 19.6 million pixels, it can often match a conventional Bayer sensor with a much higher pixel count for detail.


Herewith a few resources you can download and examine and/or fool around with.

This is the first image I'm making available, which was shot in X3F format:

Here is the full-size JPEG (5424 x 3616, 25 Mb download) developed to taste from the X3F in Sigma Photo Professional

And here is the original X3F RAW file (59 Mb download)

Secondly, here's one which was shot as a DNG and processed in LightRoom:

Here is the full-size JPEG shot as DNG, developed in LightRoom

And here is the original DNG file (caution: 108 Mb download)

To download, just right-click and select whatever option your browser offers to download original