Posted on

The ugly duckling

‘Dad, why did you get such a disgusting looking camera!’ is what came from my seven year old’s mouth when the little Sigma Quattro arrived.  It’s since become known as the ugly duckling in the family.

For the last few months I’ve been shooting with the little Sigma Quattro dp0 and dp2 besides a Nikon D810, a long lens on the Nikon and the Sigma’s for wider angle work.  It’s not a bad combination and offers some flexibility but I get a lot of comments on the little ugly duckling’s when I’m out and about so I’ve decided to write up on the experience and make a comparison between these two very different tools.  For the record, I actually think the little Sigma’s look pretty good.

If you’re unfamiliar with the Quattro, it’s a mirrorless camera, perhaps half the weight and size of the Nikon has about 19.6 super special megapixels on a crop sized sensor, it’s a third the price of the Nikon body and uses a fixed prime lens, you don’t swap lenses, you swap cameras.  The Sigma’s talking piece is the Foveon sensor technology, which is different to anything else on the market.

Sigma Quattro dp0 and dp2, shown fitted with universal L brackets
Sigma Quattro dp0 and dp2, shown fitted with universal L brackets

I shoot mostly landscapes so this review will be biased towards that type of shooting, which is where the Quattro excels.

Sensor tech

The comparison wouldn’t be complete if I didn’t touch on the sensor technology.  The advantage of the Foveon sensor in the Sigma is the ‘layered’ design, on traditional bayer sensors found in just about everything else, the blue, green and red photosites (or pixels if you like), are laid out beside each other in a pattern so each point can only record red, blue or green.  An algorithm is used to interpolate the missing colours at each photosite.  The Foveon sensor is layered, so at an individual photosite the amount of red, blue and green light is captured without interpolation, this helps define edges, especially at edges with high colour or tonal contrast, and it reduces or eliminates moire patterns.  Simply put it helps make sharper images.

So how does it work in real life?  The quick answer is  quite well, under the right conditions.  But can the Sigma out resolve the Nikon like some test charts have suggested? That’s a longer answer I tackle below based on my observations.  More importantly there are a few strange quirks you need to know about the little Sigma’s, and as for the Nikon it’s an excellent tool but still not perfect either.

The Sigma in use

The dp0 is 14mm = about 21mm equivalent

The dp2 is 30mm = about 45mm equivalent

To Sigma’s credit they’ve had the guts to think outside the box and provide a camera with some definite advantages over a traditional DSLR; package size, light weight, reasonable price, simple menus and operation, different sensor technology, and competitive image quality.  To be honest quattro’s are lot of fun when you’re accustomed to a bulky SLR, but there’s some oddness about them too, things us DSLR users just aren’t accustomed to.  Some of these quirks have me shaking my head at times when it seems basic expectations aren’t met, but in the end none are real deal breakers for me personally because each drawback has a pro weighing up against it.  There are however annoyances that simply shouldn’t be there, listed in order of most annoyance….

Quattro Quirks

Sigma Photo Pro software – Much much much too slow, and you can’t use other raw converters.  I haven’t even bothered to master this software because it’s just so different and so slow it doesn’t seem worth the effort.  I’ve found a workaround that works for me.  Images can be batch processed using presets, which is how I handle each shoot, I select a preset I’ve previously made and hit go, it can bulk convert the raw files into tiff’s that can be read by other software.  The processing still takes around 15-20 seconds per image on my PC but it frees up your time as it churn away in the background.  Opening each image manually would be unthinkable.

Image review too slow – I shoot in raw, with raw files there’s a 5 second delay between capturing an image and being able to view it on the LCD, for jpg only it’s much quicker.  Quick preview can be switched on which displays the image shortly after capture, but that’s only quick preview and not an image that can be inspected in detail.  On other camera’s I don’t use ‘quick preview’ but on the Sigma I leave it on simply to show the quick preview if I want it.  It’s not a big problem for my kind of shooting but for some the delay would be frustrating.

Histogram and level – I’m getting used to this one, but I can’t understand why the histogram and level are positioned near the middle of the LCD where they obscure significant parts of the image, they should be positioned near the edges where things are ‘less important’.  Sigma, why not make the level from a series of dot’s like in the d810 viewfinder?  And make the histogram more opaque, smaller, or beside the image (with a larger LCD) instead of obscuring so much image space?

Quattro dp0 rear view with shooting screen shown at top right, with histogram and level turned on.
Quattro dp0 rear view with shooting screen shown at top right, with histogram and level turned on.

9 focus points.  This one can be issue for me, I use single point focus to control my focus point.  But there are only 9 positions and none of them anywhere near the edge of the frame. Occasionally none of them line up with the right feature to set focus which is a bother when working on a tripod.  If you need to capture a near and far focus image of the same scene for focus stacking, the only option is often to use manual focus which isn’t particularly easy to judge.  Also, the controls are not intuitive, the down button is used to display and change the focus points.  On the positive side manual focus is selected quickly with the up button and has a distance scale displayed as a guide.  It can display a close up magnification but only on the selected focus point which can’t be positioned exactly where it’s needed anyway.

Raw file size – 60MB each large raw file plus 10MB per jpg, that’s 70MB per image, and then they are converted to tiff’s to make them usable in other software which generates another 110MB, that’s a total of 180MB per image captured!  Sure you can delete the original raw’s or jpg’s later but that might not be wise.  So why shoot jpg’s too?  That’s because only Sigma software reads the files, you need the jpg to see what’s on the card in any other software before the tiff’s are generated.

The battery door catch has a bit of an issue, it isn’t spring loaded like other cameras and sometimes posp open during handling.  Fortunately the battery remains in place with a separate catch.  Sigma please fix this this one, it’s low hanging fruit for the design team.

Every other camera has a card slot on the right side, the Sigma has it on the left so if you’re using an L bracket with the Sigma it can be a little difficult to access.  Plus the door itself is a floppy rubber thing which is a bit awkward to access.

I usually leave the ISO set low at 100 for landscapes so I find it usable (but not desirable) to bury the ISO selection in a menu without a dedicated button, ironically if the images above ISO 400 were more acceptable I might feel the need to change it more often.

The battery life is probably similar to other mirrorless cameras but noticeably less than a DSLR.  Sigma provide two batteries which is excellent.  I don’t normally find the battery life a problem unless I head out without a full charge, something I can get away with on the Nikon.

Phew, glad I got those off my chest, now lets look a bit further….

In operation

Firstly the ergonomics and styling.  The Quattro looks spaceship futuristic but the unconventionally shaped grip can take a little getting used to.  The dials and buttons themselves feel good individually but as a whole they are slightly awkward and the positions of some controls could be improved, especially the AEL button and the 4 way dial.  On the whole I wouldn’t say these adversely affect shooting too much.  The front and rear dials are real positives, they work similarly to the front and rear dial on a Nikon DSLR by providing quick access to settings in each mode, and they are customisable to work the way you are accustomed to.

Speaking of customisations, the playback and shooting display screens can be customised somewhat within the options provided.  I’d like to see more options such as placement and style of the level, and individual selection for the other icons, but as it is, it doesn’t take much to cycle between screens during use.

I shoot in Aperture priority mode with the Quattro rather than manual mode like I typically use with a DSLR when shooting landscapes.  That’s because the Quattro has a histogram display on the LCD that can be used to judge exposure, with the Nikon I typically use the optical viewfinder which contains more limited information on the resulting exposure.  A histogram is a great reference while shooting, it’s easy to understand and adjust the exposure before the image is captured. With the Nikon in Manual mode I use spot metering which is a bit more fiddly than the direct feedback of a histogram.

As for LCD’s, the Sigma’s is pretty ordinary, it has no where near the clarity of an optical viewfinder and seems low in resolution against the Nikon’s which makes judging focus while shooting difficult at times.  Reviewing captured images is straight forward enough, the center button provides a zoom function while the dials adjust the magnification and image number as you might expect.  The Sigma seems to have an unusually deep depth of field which is great for landscapes so sharpness from front to back is less of a problem even if it’s a little difficult to judge off the rear screen.

Image quality and appearance

The attributes Sigma got right are what really make it shine, image quality, especially sharpness, is one of the pro’s.

Optimal sharpness is at around F5.6.  The lens in both the DP0 and DP2 are sharp from edge to edge, particularly the DP2.  There’s rarely an issue at the corners that’s problematic.  Although not perfect its very competitive with the Nikon and a prime lens in many cases.  Where it falls down against the Nikon is in the shadow details, the Nikon retains noticeably better shadow detail and the absolute resolution on the Nikon tends to extract more detail overall.  The lens used with the Nikon makes a difference of course, the Nikon 24-70 F2.8 for example (previous generation) is weaker around the edges than the Sigma, but a Nikon 50mm prime, or the 16-35  generally out resolve the Sigma.  I say ‘generally’ because there are so many ways a camera can be used.  Personally I think the Nikon is ahead for most images and most situations but the result is still excellent with the Sigma.  Bear in mind that good technique comes into play, use either system sub-optimally and the results will be on par.

Related to sharpness is ‘depth of field’, and even accounting for the crop sized sensor I find more consistent sharpness from front to back with the Sigma than the Nikon, it’s just easier to keep all elements sharp, and this turns out to be one of the reasons I enjoy using  the Quattro’s.  I can’t explain why it has this characteristic, I assume it’s partially in the optics, perhaps the lens field curvature is more under control, I really don’t know, but it may also be a result of the Sigma sharpening.  With the Foveon sensor, sharpening can be applied more heavily without breaking high contrast edges.  I don’t think it’s related to theoretical hyperfocal distance differences or sensor sizes.

Dynamic range is less of a Quattro strength, if for example you expose for the highlights and expect shadow details to fall into place, you’ll do better with the Nikon in scenes where shadow detail is important, but that shouldn’t be too surprising given the sensor size difference and considering the Nikon is virtually class leading in that respect.  I’d guess there are a couple of stops less usable shadow detail on the Quattro, I haven’t bothered to test that in a more structured manner, instead I tend to learn how a camera behaves and then work with it.  This narrower dynamic range has more effect on higher contrast scenes, I find myself running into the boundaries more quickly and shooting more multiple exposures with the Quattro.  Speaking of exposure bracketing though, the Sigma does it very well, if you set a 2 second timer and use exposure bracketing (easily set through the quick access menu), it will fire off the three shots in quick succession after the timer, works great.  If you do manage to clip highlights or shadows in an image they tend to fail more abruptly and more noticeably than on other camera’s I’ve used.

Low light situations which generate long exposures, perhaps longer than 10 or 15 seconds can get problematic, unwanted noise and strange patterns can creep into these images, particularly the shadows.

Another pro for the Quattro is the ‘special look’. Compared to Nikon’s raw files rendered in Adobe products, there’s a look about the Sigma images that can really stand out, especially for landscapes.  However if you’re shooting skin tones  you may feel the need to call an ambulance after you find the colour drained from your mother inlaw’s face, or an oompa loompa sitting in the corner.  Unfortunately skin tones can often look ‘off’ even with ‘portrait’ rendering.  Strangely though for landscapes a combination of the Sigma sharpening, tonal control and colour rendering can give a very natural look.  The rendering favours more saturated highlights and less saturated shadows which is more in line with our natural visual perception than what comes from the Nikon.  Greens tend to come out noticeably less saturated and feel more ‘right’ than the Nikon green, similar story for some other colours, the rendering often just feels better.  There’s occasionally a colour disaster from either system but I do enjoy the alternative and almost film like look the Sigma provides.

Black and Whites are also handled well, even straight from the camera, and there’s a dedicated B&W rendering in the raw converter with lots of good options too.  I’m sure you could write an essay just on the B&W conversions, but I’ll just point out that they’re very pleasing.

So what else?

Lens caps don’t usually get a mention, so thanks Sigma for finally providing a nice grippy lens cap, smooth & slippery lens caps just bug me.

How about L-brackets, I’m using a universal fit L-bracket (about $7 shipped from China), they are working fine even if they aren’t quite square, the only issue is that they partially obstruct the SD card door access.  The bracket needed a little bit of filing and modification for best fit.

No viewfinder? No problem, a loupe works fairly well and provides an huge viewing area.  I’m using a Kinotehnik loupe that attaches magnetically to a thin frame that can be adhered to the LCD surround.  It works well but would work much better if the LCD had a decent resolution.  The only issue I’ve found that it can fall off if you bump the camera too hard, so it’s best to have the loupe strap around your neck or the tripod itself.

Quattro dp2 with Kinotehnik loupe
Quattro dp2 with Kinotehnik loupe

A remote would be nice, but even the Nikon should do much better than it’s 10 pin connector remote.  Give me a small infrared remote any day.

No image stabilisation, not such a problem for shooting on a tripod, but when shooting handheld with a limit of around 400 ISO for clean images, stabilisation would can useful, the B&W city images below were pushing the limits of hand holding without IS.

Turning the Quattro off part way through an exposure won’t force a capture in progress to stop like the Nikon does, not much of an issue, but it can be a problem if you’ve accidentally triggered a long exposure and you need it cancelled to continue shooting.  It’s only happened once or twice but is very frustrating, the solution is to disconnect the battery briefly and switch the camera back on.

No built in flash is no big deal for landscapes, and since the Quattro isn’t much of an indoor camera due to the poor high ISO quality it might be of limited use for many situations.

Final words

I’d love to see Sigma do well with the Quattro range, they’ve taken a real risk to produce something unique and different but it has strong competition from a range of more versatile cameras.  When it excels, it’s up with the best, the images have a great look about them and generally lots of detail, but there are quite a few quirks to deal with along the way.  So how would I recommend it?  It’s certainly not for everybody, it favours certain types of shooting and certain personalities.

Given the Quattro’s limitations I think they work best when supplementing another camera system.  If you already have a mirrorless system and are happy with the results, it’s probably not for you.  If you use a compact camera and are after a second camera with improved image quality it could work for you, if you’re supplementing a DSLR it can work.  But be aware of the limitations (low light work especially).

If for instance you carried a DSLR with a long zoom and kept a DP0 or DP1 in the bag for wider angles it could work, especially considering you’re getting a complete camera and lens with a Quattro for the price of a DSLR lens.  The DP2 and DP3 are 45mm and 70m respectively.  I find having a DP2 on hand is almost as good as keeping a 50mm lens in the bag, and it means I don’t have to switch lenses.  It gives me an option if I want to travel lighter by keeping the DSLR at home, or if I just want to keep a camera near by when I’m not actually out shooting.

DSLR’s and most other mirrorless cameras are simply more versatile so it’s pivotal that the Quattro image quality can stand up to scrutiny, and in many cases it will if used properly, unfortunately for many users the trade off’s may just not be suitable.

 Finishing message to Sigma

The Quattro is both excellent and lacking, I enjoy the results but getting there is more difficult than it needs to be.  Please keep working on those quirks and you’ll have a competent all round system, I can’t wait to see what comes next.

Example Images

The images are demonstrated below to provide further commentary, but there’s a limit to what can be inferred from these (lightly) processed and downsized files.

B&W conversion, no other adjustments. Melbourne city scene.
Melbourne City scene.  B&W conversion, no other adjustments.

This image was taken with the dp0 at 1/8th second and ISO 400, on the edge of what I could hand hold.  The image was converted to B&W without further adjustment.  The B&W output generally provides a pleasing contrasty look.


Textures in Iron
Textures in Iron

The Quattro tends to handle textures like this well, providing fine details and variations.



The colours just seemed a bit off in this image, some curves and colour balance was required to make the faces appear correct, but there still seems to be a bit of a cast in areas.


The Farm

With little adjustment landscape colours can appear very natural, I think it’s due more in part to Sigma’s raw file rendering than the sensor technology, but I could be mistaken.


A bit creepy

A black and white taken in Melbourne’s Royal Arcade.

Pulpit Rock, Cape Schenck
Pulpit Rock, Cape Schenck

A half second exposure in low light, the deeper blacks are starting to show strange patterns and noise when viewed at full resolution.  This image has more processing than the others so differs further from the original look, still, the characteristics of the original appearance are quite evident.

The Sheep
The Sheep

The wool details are captured sharply and the transition between areas in focus and the background is smooth.