Sigma SD Quattro Review

Sigma SD Quattro Review (APS-C Model)

The Sigma SD Quattro builds on the dp Quattro range of cameras, which are all fixed lens APS-C sensor cameras, each model with their own particular focal length lens.  The SD Quattro builds on that by providing a more well-rounded camera, and the advantage of being able to use the Sigma SA mount ‘dSLR’ lenses, specifically their excellent Global Vision – Art, Contemporary and Sports lenses.

sigma sd quattro accessories

As a disclaimer I must mention that this camera was supplied to me by Sigma UK, along with a 24-35mm f/2 Art lens.  As always, this never influences my writing and I’m always honest and up-front whenI find issues with things I don’t ignore them – more often than not, I’ll say so!

Throughout this write-up you will find various images I’ve taken with the SD Quattro.  You really must click on them to see the larger versions to really appreciate them.

I have been fortunate enough to shoot with all the dp Quattro cameras, and really love them for the images they produce, which is why I was so interested in getting hold of an SD Quattro.  I have to say that personally I’m more interested in the “H” model, which will have the slightly larger APS-H (1.3x crop) sensor and approached Sigma asking when it was due for release as I was wanting to buy one.  At the time they didn’t have a definite date for release, but kindly said they would lend me the APS-C model that had already been released to see how I got along with it.

As always, I don’t write my reviews until I’ve had a good long while with a camera and had the opportunity to really put it through it’s paces.  I’ve mentioned before that some things that you think are irritating at the start tend to become less so as you use the camera more, and certain issues don’t become apparent until you use the camera in real-world situations.

The SQ Quattro has a fairly standardised APS-C sized sensor, but what is unusual with these cameras is the Foveon sensor that they use.

The Foveon sensor in the Quattro range has an image resolution of 19.6Mpx, although with some clever processing it can produce images of 39Mpx resolution (in JPEG only).

With a typical Bayer array sensor used in the majority of cameras, a block of 4 photo-sites are combined to give a specific colour and luminance reading for an individual point within an image.  Each block of 4 photo-sites has a colour filter array over the top of the sensor that allow individual photo-sites to detect luminance for a particular primary colour of light.  The four photo-sites are split into red, blue and two green.  This information then requires processing to construct the image into the pixel-by-pixel image we see.

Here it becomes slightly complicated because if we simply created an image pixel for each block of 4 photo-sites then the sensor would have a reduced resolution.  This is where the term demosaicing arrives, something you may have heard of.  Demosaicing is a process that combines overlapping photo-site blocks to produce an image with a higher resolution.  It isn’t without problems and can create moire, as it uses some of the same photo-sites for more than one pixel of the final digital image.  This also means that more than one part of the sensor is used to create different parts of the final image, so interpolation is used rather than discrete data for each pixel, leading to a certain level of guesswork (albeit a very sophisticated level of guesswork) to create the final image.

The Sigma Foveon sensor does things differently.  It works in 3 stacked layers, each layer detecting a different primary colour.  The top layer has four photo sites (hence the name Quattro) that are used to not only detect blue, but are used as the basis for the resolution of the image.  The second layer detects green and the third layer red.

The Quattro sensor has a 19.6Mpx resolution blue layer and then 4.9Mpx for green and red.

This arrangement has the advantage of capturing each individual colour for a specific pixel in the image, as each layer records the luminance of the same part of the image you are capturing.  This means that there is no demosiacing, eliminating issues arising from that, and providing incredible detail.  Not least of which because the sensor does not need an anti-aliasing filter.

The Fujifilm X-Trans sensor is another attempt at increasing sensor resolution and reducing noise by using arrangements of 6-photosites with a randomly arranged colour array filter.  This does a great job on the whole, especially in terms of sensor resolution and noise reduction, but is not without issues.  It does not completely illuminate moiré, and has a particularly complex demosiacing algorithm.

The only real problem with the Foveon sensor is that computing the information from the three layers and combining it into a digital image, although superficially it seems like it should be the simplest of them all, takes a lot of processing power, and therefore taking both time and sapping battery life.

The SD Quattro Body

There will eventually be two SD Quattro models, the one I’m reviewing here, which has a 39Mpx equivalent APS-C sensor (1.5x Crop on from 35mm), and an “H” model that has the APS-H (1.3x crop from 35mm) with an equivalent resolution of 51Mpx.  Both cameras are ‘mirrorless’ in that there is no moving mirror box as in a dSLR.  Physically they will be identical though.

The body is an unusual design and unlike other mirrorless camera systems has a protruding flange for the lens.  This is because it accepts their existing Sigma SA mount dSLR lenses from the Sigma range of dSLR cameras.

Sigma SD

Phase One P30+ (120mm, f/11, 1/100 sec, ISO100)

This has two main advantages.  If you’re a Sigma fan and have existing lenses then you can simply use these lenses on the camera.  The second being that straight out of the box, there is a wide range of lenses available for the system, and we’re not stuck with a small range as is common with a new mirrorless system.  The main disadvantage to this is that you can’t adapt lenses from other systems onto the Sigma SD Quattro.  However, there is something we can do about that and turn it into an advantage.  If you use the Sony NEX or a7 series of cameras (E-mount or FE-mount) then you can use the Sigma MC-11 (SA version) lens adapter to allow you to use the Sigma SA lenses on your Sony system, the great thing with the MC-11 is that they will behave like native Sony lenses so you get access to all the features you would with a Sony lens.  More about that later.

The camera body is an unusual shape, although maybe not quite as unusual as the dp range, and it fits well into the hand.  One thing you’ll notice when you pick the camera up is how solid it feels, this isn’t a particularly light system, but that solidity really gives you confidence in it.  The entire body is metal.

Sigma SD

Phase One P30+ (120mm, f/11, 1/100 sec, ISO100)

On the rear are two screens, although it doesn’t appear so at first as they sit side-by-side behind a glass panel.  The traditional ‘rear screen’ for viewing the image, menus etc, and to the right is a second screen that shows you your camera settings.  On a dSLR this would be what typically is shown in the screen on the top of the camera, however it makes so much more sense for it to be on that back as you don’t have to move your eyes from the back of the camera to check your settings.  It somehow seems so much more logical than having the display on the top – although you’d not think that until you use this camera.

Above the rear screen is a built in EVF – that’s one of the big things that was missing from the dp Quattro, and really makes a huge difference to the use of the camera.  The EVF is bright and clear and in-line with any of the modern EVFs you see on cameras today.

I’m happy to say there is a proper physical button to switch between the screen/EVF/auto modes – this is something I use regularly and having a real switching button that shows you what mode you’re in is something I really appreciate.  Next to that is the view mode button and below the screen Play and s/c buttons.  The rest of the buttons are all placed over to the right hand side.  Next to the settings display are a row for changing the settings quickly and then further over are the usual suspects, D-Pad, Menu AE/L Lock etc.

Sigma SD

Phase One P30+ (120mm, f/11, 1/20 sec, ISO100)

The QS button on the top of the camera is a customisable Quick Menu that gives instant access to eight different camera settings such as ISO, WB, metering, file quality settings etc.  Each option can be changed through the menu and you can order them whatever way you wish.  In typical use you can access everything you would need from this QS menu without having to go into the main menu during a shoot.  An excellent well thought-out method for when you need to make quick changes, and for the most part it keeps you out of the menu.

Sigma SD

Phase One P30+ (120mm, f/11, 1/100 sec, ISO100)

Sigma SD

Phase One P30+ (120mm, f/11, 1/13 sec, ISO100)

To the left of the body is the SD card slot and USB port, covered by a rubberised door.  The battery sits within the grip part of the body and is a much larger batter than in the dp Quattro series, which does mean a much longer life.

The main menu is easy to navigate with pages separated by function and are presented in a clear logical manner.  You are not overwhelmed by options, but given just the right level of adjustment to the various functions of the camera.  I don’t want to go on about each menu option as I’d rather spend the time talking about actually using and shooting with the camera.  I produced a video going over the while camera and through all the menu options which you can view below if you want to.

Shooting with the Quattro

Like the dp Quattro, this is not by any means a point-and-shoot, spray-and-pray camera.  Shot-to-shot time isn’t going to blow you away, and image review takes what seems like hours when you’re on a shoot.  However, when you get to see the results the Quattro can produce you can forgive it almost anything.

Auto-focus is quite acceptable, although by no means dSLR speed, it’s very usable for most normal situations you’d be shooting in with this camera.  I even managed a bit of “street” with it!

The one thing I found missing when shooting outdoors with the dp Quattro camera was an EVF of some sort, the SD Quattro solves that with the very good built in EVF.  The screen is useable even outdoors, but the EVF just makes things a whole to easier, and also offers a more stable hold to avoid camera shake.

The Quattro cameras have a series of built-in colour profiles.  Standard, Vivid, Neutral, Portrait, Landscape, etc.  It is very much worth choosing the correct profile for whatever you are shooting.  Not only will the JPEG produce nicer looking colours for that particular scene, but if you use the Sigma PhotoPro software, the RAW files will be processed automatically using the colour profile you chose.  You can, of course, change that setting in the software, but certainly for landscapes and portraits I found that using the colour profiles provided by Sigma produced excellent results that were not worth spending extra time trying to replicate.  The image below is taken in the Cine profile, which I really like!  It doesn’t work for all subjects though.

In my mind, the Sigma SD Quattro is really comes into its own and is most successful when being shot in a studio or when shooting landscapes.   In the studio paired with a macro lens you can get incredibly detailed images of products with lovely tones.

Another great use for the camera are portraits, although given the bitingly sharp detail, some subjects may not agree, and sometimes in certain circumstances I have found myself reducing clarity to take the edge off the sharpness.  As I said, the SD Quattro is easier to handle in a controlled environment of a studio, but I do use it on location shoots such as this shot below.  However, this is lit with artificial light so there is a certain degree of control and I can limit the ISO to the more useable range of the camera this way.

When shooting landscapes, because of the fine detail the sensor can resolve, they look absolutely stunning, and print beautifully.  Unfortunately given the time of year I’ve been very restricted to the amount of time I’ve been able to go out and shoot landscapes, so this isn’t the best example.

Something I love to do with the Quattro is to produce large panoramic images.  Because of the amazing resolution, you can get the most incredible fine detail that would print into a truly enormous high resolution image.

Infra-red camera!

One of the interesting features of the SD is the fact that the IR filter is removable and sits quite far forward within the lens mount.  This not only has the benefit of preventing dust get right onto the sensor, but with an IR filter on the lens it means that you can turn your camera into an Infra-Red camera very easily without having to get it specially modified.  You can see the filter in the image below reflected in the light, and the clips that hold it in place on either side.

Sigma SD

Phase One P30+ (120mm, f/11, 1/100 sec, ISO100)

This is a truly unique feature of the SD Quattro in modern cameras.  You can modify most digital cameras this way by sending them off to be adapted by a professional, but the fact that the IR filter is located close to the lens and is actually removable by the user means it won’t cost you anything beyond a lens filter.  Once you’ve removed that IR filter in the body and installed a filter the blocks all visible light, only allowing infra-red light in, you then have an instant IR camera!  I have to say this isn’t really my thing, but it does create some unusual images and could be quite appealing if you’re into it.  You need to shoot in mono mode though as otherwise the image, as you may expect, is just red with no other colour!  The other issue is that because you’re blocking the vast majority of the light going into the camera, you’ll either need a tripod or a very sunny day.  Having said that, the images below were taken on a moderately bright [sunny] winter day.

One of the downsides to the large amount of processing needed on the files is that the full image preview can take several seconds to be available.  You can see an almost instant preview, but that is a low-resolution version, only really any use to check exposure.  When you want to confirm focus before moving on to another shot, you have to check the actual file.  Having to wait between shots to confirm this can really break up the rhythm of a fashion shoot, although with landscapes for example, it isn’t as much of a problem.  Sometimes you just need to hit preview, have a quick look at the focus point to confirm you’ve nailed it and then you can move on.  I was hoping that this may have improved from the dp series, but it isn’t really significantly faster.

Image Quality

I have used a wide range of cameras. I’ve owned Nikon dSLR’s, including the D800, the Fujifilm X-Series (pretty much all of them!), loads of different mirrorless cameras, a Sony a7, and a Hasselblad H3DII-39 and I currently shoot studio work with a Phase One digital back.  I can honestly say that the dp Quattro is the closest thing I’ve ever seen to medium format without shooting medium format.

I think unless you’ve shot digital medium format it is hard to understand the difference between that and “full-frame” 35mm, APS-C or any other smaller format.  It is nothing to do with sharpness or anything that is particularly measurable, there is just a certain feeling to a medium format image that I have never seen before in any other camera until I saw the images from the dp Quattro, and now the SD Quattro.  It’s a richness of colour, a super smooth graduation of tones, a crispness in the detail that just hits you as soon as you see the files.

When you read things like they say it gives a 39Mpx level of detail and hear them talk about medium format quality you just dismiss it as marketing drivel, but in this case it really is true.  I genuinely love the feel of the images that come from these cameras, and for me that far outweighs any awkwardness in use or any criticism you can throw at them.  At the end of the day, if you want to present some truly outstanding images from what are very reasonably priced cameras given the quality then I don’t think you can beat them.

The images below were taken on a Sigma SD Quattro, Nikon D810 and Hasselblad with a Phase One P30+ digital back on.  All three images are straight RAW files from the camera and imported into their respective editors (Sigma Photo Pro, Capture One, Lightroom for the Nikon) with the default settings applied then exported.  The only thing that was changed between cameras was the aperture to get a similar depth of field.  See if you can tell the difference before scrolling down to see the answer to which is which…

and the obligatory 100% crops (in the same order)

…scroll to answer…




(don’t go beyond here if you don’t want to know yet!)



1, Nikon D810

2, Hasselblad/Phase One

3, Sigma SD Quattro

Pretty close, although I would say from the crops that the Phase One and Sigma SD look to have produced slightly more detail, they are all so closely matched it’s hard to pick a winner other than personal preference.  Really quite amazing from three such different cameras, not only in price but in design as well.  Really makes you see how good the cheapest of the lot (by a long way!) – the Sigma SD performs amazingly well in this type of situation and if you’re a product photographer then you really should seriously consider this camera.  The Hasselblad and Nikon had prime lenses on giving the best quality images, where the Sigma had the (albeit excellent) 24-35mm f/2 Art lens attached – it may have performed even better with one of the Sigma Art Prime lenses.

Dealing with files from the sd Quattro (and the dp Quattro for that matter) is a bit of a pain with no support from Adobe in Lightroom, my method currently is to import into Sigma Photo Pro, then export to TIFF files.  However, the new H model sd Quattro with the larger sensor had the option to save directly to Adobe’s DNG raw format, and Sigma have said that they will bring this to the APS-C sd Quattro, and to all dp Quattro cameras by way of a firmware update in the future, so that’s a huge deal for anyone like myself who uses Lightroom.  Not only can we import and edit straight into Lightroom, but DNG raw files process very quickly indeed, so a double bonus!  The is a small caveat in that the DNG RAW files are 12-bit colour info where the native X3F files are 14-bit.  How much difference this makes in the real world would need more testing to see, I suspect that unless you’re really pushing the bounds of the sensor then not as much as you may think, but I haven’t been able to test that to confirm it.

In General Use

I have to mention battery life.  Unlike the dp Quattro range where you get two batteries in the box with a new camera, the SD Quattro only comes with one.  This, however, is a much larger battery than the ones that come with the dp Quattro and consequently do give a lot longer battery life, I’d estimate at around twice as long.  Having said that, battery life is not a strong point of mirrorless cameras where the sensor and screen are ‘always on’ so compared to a dSLR you are not going to get anywhere near their battery life.  As a long term mirrorless camera user this doesn’t bother me at all, although I would suggest you stock up on at least one spare battery

With the full-frame 24-35mm lens, this is not a light combination.  I managed to get some time with the 30mm f/1.4 that is bundled with the camera as a kit and it makes a lot more sense.  The 30mm f/1.4 is an APS-C format lens, so it much smaller and lighter yet still superb optically and makes the SD a much more viable proposition for carrying around with you.  At £999 for this kit (SD body + 30mm f/1.4 lens) it is a very good deal and I’d certainly recommend that over getting the body only at £799.

High ISO

The base ISO for the SD Quattro range is 100, and if you can shoot at that then I would strongly recommend that you do so.  Use a tripod if necessary and/or artificial light if you can because ISO 100 gives you the absolute best quality from the Quattro.  ISO 200 can be used with minimal loss of quality and colour, but beyond that I have to admit that the colours start to go off quite quickly and I wouldn’t even consider using ISO 1600 or beyond, although you’d get away with ISO 800 if you really had to.

What is unusual though is that detail is well preserved right into at least ISO 800, and even beyond.  Colour information is affected far more by the use of the higher ISO values than the actual resolution, which is unusual as it is usually both that suffer.  The lack of great colour at higher ISO can be overcome by switching to using the images as b&w conversions, and as such you can get superb results even at ISO 800 because of the fact that fine detail is still well retained, I would perhaps even suggest that you could use ISO 1600 to produce good b&w images.

You may start to think that this is a pretty rubbish camera now, many other cameras are easily capable of producing great quality images at ISO 3200.  With the Quattro seemingly topping out at ISO 400 for the best colour images, you could quite rightly think that this isn’t a great example of a modern camera.  I would strongly argue that isn’t the case.  Until the release of the Sony 50Mpx Medium Format sensor you really couldn’t take medium format beyond ISO200 without suffering severe loss in quality.  Neither medium format or the Foveon Quattro are cameras are designed to work as all-round, do everything, low light cameras.  Much like medium format cameras, the Foveon Quattro sensor is designed to give you the absolute best image quality you can get, and as with medium format, that only comes at lower ISO ranges.  If you want the absolute optimal image quality without spending a great deal of money, then for me this is exactly where the Sigma SD Quattro camera works.

It is worth noting that the Sigma PhotoPro software does a much better job of processing high ISO images from the RAW files than the cameras does when it produces JPEGS.  By adding that extra step you can gain what looks like a whole stop advantage in ISO performance.

Processing the images

This is probably a subject that I would write an entire article on by itself.  It really has taken me some time to get to grips with processing the images from the Sigma Quattro cameras.  You may notice that within this review a varied level of refinement between images.

I’ve been shooting with the Fujifilm X-Series cameras for a while, and you get used to a certain way of working and to how those files respond when you’re processing them in Lightroom.  The Sigma files do not respond in the same way and it takes quite a bit of time to learn how to get the best out of them.  It is a fine balancing act between preserving the beautiful graduated tones that you get straight out of the camera and processing them to get what you want out of the file.

One thing I would say is that I found the Quattro to be quite unforgiving of bad shooting technique.  Where with my Fuji cameras I can be very lazy and easily shoot at least 1 stop under or over exposed and can pull that back either way in Lightroom pretty much without anyone knowing any different, the Sigma will seriously smack you in the face if you get it wrong!  The files just cannot the same punishment, they need a fine caress rather than a heavy handed attack on the sliders as you soon find yourself with an image that too quickly looks over-processed.

The Sigma PhotoPro  (SPP) 6 software…  Yes, it is every bit as slow and awkward to use as you have heard!  Actually, in fairness, there was an update in December 2014 that made the processing of images considerably faster, and there have been several smaller updates since to improve performance and reliability, but it is still nothing like Lightroom, or anything else.  You move a slider, wait a few seconds and then the result of that change appears.  It makes using the software nearly impossible as a serious tool for adjusting the RAW files other than very basic adjustments before exporting.  The way I tend to work is to import the RAW files into that software, flag the ones I want to work with, export them as 16-bit TIFF files and then import those TIFF files into Lightroom to post process them there.  Unfortunately that creates enormous TIFF files, in the order of 120Mb each, and if you also want to store the original RAW files at 60Mb each you’re going to be needing to buy in some extra storage space!

Whilst it can be tempting to simply use the JPEG files from the camera for convenience, the SPP software does a better job of extracting detail from the files, and in particularly colours at high ISO when compared to camera JPEGs, so for my use of these cameras to produce the best quality images I can, using the SPP software is a necessary step.  Somewhat of a shame that Sigma do not work more closely with Adobe to allow processing of the RAW files directly in Lightroom.  Once DNG raw support is available across the range this will become a non-issue.

Printing the images

This is where I feel the Quattro cameras really excel.  Prints from the Quattro files are truly outstanding, producing beautiful tonal graduations and incredible detail even when blown up to sizes larger than most people would normally want.  I now have several images that I’ve had printed and framed at 20x30in (A1) size.  You can literally put your nose to the images at A1 and still see all the fine details.  I’m sure they could easily be printed at A0 size, or even greater and you would still be rewarded with amazing prints.  If I were to shoot a job where the client wanted large prints as the end result then I would pick up the SD Quattro to do that without hesitation.

Sigma SD Quattro – Sony a7 and the MC-11 lens adapter

I would not recommend the SD Quattro as a do-it-all camera.  If you have something like the Sony a7 this would make an idea companion to it, not only because it is faster but it is also more capable in other situations and with the MC-11 adapter it means you can use your Sigma mount lenses directly on the Sony a7 series and using a common set of lenses you can save a lot of money.  The MC-11 adapter means that the Sigma Global Vision lenses act entirely like native lenses on the Sony a7 (and NEX) range of cameras giving you access to the full set of features, phase detect auto-focus, tracking, face-detection etc, plus the ability to have some truly spectacular lenses in the form of the Art f/1.4 prime series on your Sony a7 for a lot less than the cost of the Sony equivalents!

I did do a video (below) showing the Sigma MC-11 with Sigma and Canon lenses, as well as a comparison with a cheaper Commlite adapter that does a similar thing.


As I mentioned within the write-up, these cameras can frustrate as well as delight at the same time.  Had I only used them for a brief period I can easily see that the frustration would have driven me to give up on them, but the more you use them, the frustration subsides as you get used to their little quirks and you end up being blown away by the images every time you look at them on your computer.  I was already used to handling the Quattro cameras from my time with the dp range, and I had hoped that the SD would be a little quicker to use, and it probably is, but not significantly quicker.  For my own taste and style of shooting that does not matter, and I’ve mentioned plenty of times that this camera is for a specific type of use, and for someone that wants ultimate image quality without going to medium format.

If you want amazing images that have a really unique look and feel that I’ve never before seen outside of medium format then the SD Quattro from Sigma cannot be beaten for that.  Coupled with the flexibility of an interchangeable lens and the EVF this makes much more sense to more people than the dp Quattro range.  Having said that, you do give up the leaf shutter from the dp Quattro range, which is a feature I love for using with flash as you can sync the flash to 1/1000th of a second with no gimmicks.

Couple the SD Quattro with an a7 and the MC-11 lens adapter and you could have a perfect combination of flexibility and image quality with the advantage of using only a single set of lenses, which lets face it, are the expensive part of your photography kit.  At £799 for the body only it is a real bargain in terms of the quality of images it produces and for studio shooters it really is a viable alternative not only to a high end dSLR but also medium format.  If you are interested in this camera I’d definitely recommend getting the kit with the 30mm lens as it suits the body very well and at only £200 more for the lens, represents a very good deal.



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