Monday, 28 July 2014

Sigma Quattro: just like a View Camera

Long ago there was a time when no pro would do without one, a View Camera, with its black cloth. Then a format de-escalation began in the 1940s, 6x6 became the dominant format, and finally the 35mm.
With digital we are going  even smaller, with APS becoming the dominant format..
 I would never have seen an old style view camera if my cousin, a good woodcarver, had not built one in wood. It took a big prime lens with a Compur shutter, it focussed on its large plates by moving an optical bench, and you could even make collodium plates for it, by painting the emulsion on a glass plate. The camera had its own tripod, it needed poses, it took time to change plates, but it  had v. good resolution and was good for all sorts of experiments.

A Lotus view camera  from Linhof
In the Digital era, the Sigma Foveon cameras take more or less the same niche although they have an APS-C sized sensor and weigh only half a kilo instead of the 10 kg of view cameras! They also have a double resolution to their nominal photosites, compared to another digital camera.
The difference is in the structure of the sensor. Instead of a flat matrix of blue, green and red photosites, they have three layers that convey the full colour information.
See here:

In the Quattro Sigma improved on its older sensor so that only the top one, the blue one carries the luminance information. Therefore the structure is called 4-1-1, instead of 4-4-4, and hence the Quattro.

With the new arrangement there are less photosites in the  colour layers below,  but bigger ones, hence they produce less noise. The advantage of the Foveon  indeed is not in the number  of photosites, but in their pixel sharpness.

The new arrangement is better than the old in that it now offers a 36 Mpx image equivalent, instead of the Sigma Merrill's 30 Mpx. on the same APS-C sized sensor.

This is yet another proof that resolution nowadays doesn't depend on the size of the sensor and even less from the size of the camera.

For the technical savy, see the discussion about the new sensor between the Sigma engineers and the Imaging Resource team is here.

There have been other improvements in respect to the old Merrill. Although the camera still takes some 4 secs to be initialised, it  records faster (2.8 seconds/shot), it focuses better (less than 1 sec), battery life however is still short, at 140 shots. Sigma provides a second battery.
 It has no video, so you must know what you buy it for :)

But the real progress is in the sensor, which now offers 25% more resolution than the earlier dp2 Merill, and one stop more useable sensitivity, up to 800 ISO.
I would say this is the consensus, although the level of appreciation varies wildly across reviewers.

These are early times, but I decided to try a review (of reviews!)  after seeing a double blind test at Les Numeriques comparing the Quattro, a Sony A7r, and a Leica S. There is no doubt, according to the users' vote,  that at base ISO the quattro beats the Sony and leaves the Leica far behind! See here

From the Sigma gallery
As soon as the ISO is increased though, the Sony is far better.
Yes but it also costs twice the price of the Sigma, the latter being € 850 or $ 1000 (note that Sigma uses a more sensible exchange rate for the EU than other brands). Note also that an APS-C sensor, can beat a FF one: a first.

Among the Cons, apart from the slow reactiveness of the camera, there is some colour smearing (between blue and yellow), which will probably require a firmware tuning, and a loss of detail in the red - see the Imaging Resource's samples. RAW however gives better results, proving that these are teething problems of the Jpeg processor.

One of the most contentious issues is the camera shape itself.
It is oblong, absolutely in a shape of itself, with its general thinness but fleshy grip. Sigma was daring and I don't know how much it will be liked by reactionary audiences of the kind dSLR-or-Death :) One needs to be eccentric from time to time.

The fact is that it is a 36Mpx equivalent camera, and if you don't hold it properly, they are going to be entirely wasted by handshake.
So here is a uTube video which might convince you of the good sense of the revolutionary shape.

My take is that this is a Landscape perfectionist's camera,  and one will use a tripod most of the times. Note that the button layout and the menus are very rational. You have a focus button on the grip. As you see there is no EVF, and some have complained that the LCD is too reflective. Sigma however provides a 45mm optical VF. On a View Camera you had to watch the image on a layer of glass in the back of the camera, so again there is something in common.

The Quattro has been called a niche camera, and is very simlar to a View Camera in that it offers beautiful, ultra detailed panoramas. In my setup it could probably supplement theOlympus E-M5 for the most taxing landscape views. Note however that the Quattro is a daylight camera, contrary to the E-M5.

I invite you now to see what a landscape artist can do with the older Sigma Merrill and the foveon sensor, here at THE.ME

I am quoting Karel Van Wolferen and its Japanese Mountain views, which offer an unheard level of detail in foliage. Note the Fuji mountain in the background.

copyright Karel van Wolferen (fair use)
The article was written to illustrate the Sony A7r, and the Foveon was used only for comparison, but IMHO it beats the Sony A7r, for its 3D effect.
Of course if you need the higher sensitivities there is no match with the Sony, which can also change lenses. But as a niche camera the Quattro is probably unbeatable! Its Sigma 30mm, an outstanding lens for resolution which I use with the E-M5,  is clearly optimised for the Foveon sensor.

As you see Van Wolferen has also a taste for composition in Landscape that can rival the Japanese masters. I am not surprised that the uses a Sigma. I am tempted too! That foliage is extraordinary. The more you magnify, the more detail surfaces up from the background. It's like having many pictures in one.

copyright Karel van Wolferen (fair use)
In some cases it makes more sense to have separate cameras for different uses, instead of having a jack-of-all-trades.
So will you, or did you buy a Quattro? The camera is just out. Let me know what you think about it, in daily use. 


As always if you want the original resolution, control-click and open the picture in a new page.

For some reason just clicking on the image opens a smaller image.

Check also the video at the CameraStore.
They don't like the grip, but at the end of the video they do some prints showing a comparison with the Merrill to advantage.

Also Sigma has just announced a FW upgrade.


  1. I would be really interested to see how this unconventional little beast handles an IR720 filter, hot spot wise.

    1. What I can tell you is only that my Sigma 30mm, possibly the same lens, has a 46mm thread.