In early 2009 I bought my first Sigma, a dp1. I have been a life-long picture-taker, but that camera re-ignited my passion for photography. I currently use a Sigma dp2s and dp1 Merrill (dp1m). This review is a bit negative on the Quattro, but please understand that it is written from a frustrated lover of Sigmas, not a stranger. Ignoring the new body shape, the Quattro, like other Sigma/Foveon cameras, delivers medium format quality at 1/40th the price and a fraction of the size. I can’t afford medium format and though I have full-frame cameras, they are bigger, bulkier and more expensive than similar Sigmas. When I can work patiently, and want a film-like image, all Sigma cameras, including the Quattro, have a unique sensor technology, coupled with superlative optics, that produce a 3-D look. Here are some photos from my early Sigma cameras. Sigma dp1 and dp2s photos.
Before I received the Quattro I hoped for two improvements, a more responsive camera and Sigma Photo software that loaded and saved images in a reasonable amount of time. My first wish has been realized–a Sigma camera that isn’t frustratingly-slow. Unfortunately, every time I put this camera in my bag I become irritated. The camera is about 2 inches wider than my other cameras.
If the Quattro were my only camera I wouldn’t mind. But what photographer would make the Quattro their only camera? (It’s too limited). Most serious photographers have multiple cameras. Therefore, this camera, for photographers carrying multiple cameras, or extra lenses, is the proverbial “poke in the eye.” The camera is a bag-hog. It is one of the great benefits of Sigmas Merrills that they gave you Nikon D800 quality in a small size.
I could lay the Quattro down flat, but then it would push the other camera out. Here is the Quattro compared to a Sony a6000.
Past Sigma cameras have been utilitarian, in a good way. The bodies are a bit slippery, but an aftermarket grip, or 2-cents worth of gaffers tape, fixes that to the user’s preference. The batteries were small, but that never bothered me. I had the choice of going light, or bringing more batteries. With the Quattro, you’re stuck with a big camera, which now makes choosing it over a full-frame more difficult.
Here is a progression of Sigma Cameras.
Onto the good. The new Quattro design uses a concept that drives bayer sensors, interpolating single pixel colors to increase resolution at the expense of color accuracy. The Quattro still samples three colors, vertically, like film, but uses a top, higher resolution layer to increase resolution. In a sense, the Quattro is like the original DP series in full-color sampling, but with some added high density pixels (4 to 1, hence “Quattro”). Excuse me if I don’t go into the details, there are better sources for this analysis (like the Sigma forum on DPreview). Suffice it to say that in good light, the Sigma Merrill cameras are the most color-accurate consumer cameras you can buy. The Quattro isn’t quite as good as a Merrill, but it delivers greater speed and over-all resolution.
I try to use a Sigma camera whenever I can. I don’t have any special love/attachment to the Sigma brand. They simply deliver the best images when their limitations don’t get in the way. So my first question is how well the Quattro will compare my other APS-C camera; that is, which should I use more? Lately, I’ve been using the Sony a6000, and have been very happy with it. Sony has really got their act together with their cameras (standard hot shoes for one!). They have been pushing new technologies for a few years now. Their hard work is paying off.
I wanted to see for myself how much the a6000 suffers from typical bayer problems against the Quatro, or if the Quattro’s somewhat partial “bayer-like” sensor change would craete bayer-like problems . (The test has nothing to do with Sony. Any Canon or Nikon camera would show the same issue.)
When I try to show why I think Sigma images are better than bayer images most people don’t see it. It seems subjective. My goal with the following test is to show objectively, what is going on, deep within the images, of both the Foveon and Bayer technologies. Again, the difference between both cameras is not obvious to most people and I’m not arguing that it should be. For those who print big, or need fine color detail, there is no need to defend these cameras.
Here is a close up of the interpolated pixels from the Sigma Quattro. As desired, the white fabric between colors is white, as it is to my eye. The dark spots are actually true-to-life, some of the black threading can be seen below the white-stitching.
Here is the same rendering by the a6000, bayer sensor camera.
This is a problem of ALL bayer sensor cameras. When a green pixel, say, borrows red and blue values from neighboring pixels it can come up with a value that is not neutral. You can see how the red bleeds a bit into the white, and how the black allows red pixels to slightly saturate to orange on the white. The farther one stands away from a print or screen, the less visible these differences are. Indeed, in most cases, one cannot see the difference.
The Quattro is better at keeping colors separate. Bayer cameras “smear” color, but it isn’t noticeable to most people. Physiologically, we’re more sensitive to contrast than color fidelity. Again, at the resolution we view most images at, these differences are not apparent.
Even with pure colors, bayers have trouble exactly calculating proper pixel color through horizontal interpolation.
Now the Quattro image
What these tests tell me that on the basis of pure IQ, within 8 stops of dynamic range, the Quattro is better than any other bayer camera. However, the quality comes at a huge cost in speed and flexibility. Sigma has made improvements with the speed of the camera, but has not improved the software and has added a radical body design to the mix.
In pixel-deep, pure image-color-IQ, no other camera touches a Sigma, not even the venerable Nikon D800, IMHO. For black-and-white photography, Sigmas are also exceptional. Bayer cameras introduce tonal inconsistencies, due to the different color filters on each pixel. The problem is not academic. Leica has a b/w-only camera, without bayer filters, which sells for $9,000. Because Sigma cameras use vertical sampling, they also produce exceptional b/w data.
If Sigma is reading this, here is my wish list. In general, FOCUS all your camera resources on making the best, small, low-light ISO camera available. You’ve been doing this for years, but I feel the Quattro is getting off-track. 1.) Rebuild SPP from scratch to make is fast. It just needs minimal adjustment sliders, white-balance and exposure adjustments (only what can’t be done in Photoshop). EXPECT everyone to use PS, or something similar. 2.) extend the grip forward on the Merrill (like other cameras) and put in a bigger battery to run a STRONGER processor. If the Quattro doesn’t have superior IQ to the Merrill, drop it. Don’t worry about making the battery last, per number of shots, make it powerful to clear up the camera buffer as fast as possible. And again, EXPECT most photographers to carry more than one camera; the Quattro is too wide.
If the Merrill shot as fast as other cameras at ISO 100, and you could process those files as fast as a Canikons, it would be, at ISO 100, a camera most photographers could not ignore. If more people bought Sigmas I’d breath a little easier. I don’t want to shoot in a photographic world without these truly unique, and beautiful images. Finally, a quick test-shot of my daughter, f2.8, the first one I took with the Quattro.