Article: Sigma SD9 mini review

[Ahmad Bhai]

Sigma SD9

I am trying to recall how i stumbled upon SD9. I had already been happy using Fuji S2. Having been influenced by Sergio Leone's Dollars Trilogy, the lone gunman outsider of Foveon appealed to me straight away.
SD9 was rather clunky and slow i liked it.

Specification : SIGMA SD9 - SIGMA CORPORATION

I could only use it as iso100, on a few occasions iso200 and once or twice at its max iso400.
Sigma Photo Pro (SPP) software which converted X3 files to tiff and jpeg was arcane compared to Aperture, Lightroom.
I could put on a cuppa whilst i waited for one image to load.


SD9 uses a Foveon sensor.

(Diagrams courtesy of Foveon)


Bayer : at each pixel the photodetector detects either red, green or blue, i.e. Bayer does not see full colour at each pixel, just 1/3 of colour. A demosaic (Demosaicing - Wikipedia, the free encyclopedia) algorithm then interpolates (calculates) the other 2/3 of colour from neighbouring pixels to reproduce the scene.

Foveon : at each pixel the photodetector detects red, green and blue, i.e Foveon sees all of colour info at each pixel. This means there is no interpolation (calculation) from neighbouring pixels to reproduce the scene.



The various aspects of Bayer vs Foveon has been debated since SD9 and continues.

What can be agreed upon is :
1. Foveon is 3 layer like film.
2. Foveon has no CFA (Colour Filter Array) demosaicing, interpolation of Bayer sensors.
The only other commercial 35mm stills digital camera to date is Leica Monochrom.
3. There is no AA filter.


Colour : in certain scenarios Foveon can give a different look, perhaps these two SD9 images may illustrate.

Black & white : along with Leica Monochrom, Foveon can be said to be truer than Bayer CFA sensors due to no demosaicing interpolation.
Here are two SD9 black & whites.

All four images i took with kit lens Sigma 18-50mm f3.5-5.6.
The lack of AA filter and no demosaicing interpolation to me made any lens sing


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To add, for me it matters not whether Bayer or Foveon.

 

[Pete Askew]

Thanks for that superb summary / review. I have always been interested in the Fovean concept and am seriously tempted by one of their compacts. When the conditions suit, they do produce some wonderful results. These examples illustrate that perfectly, especially the B&W ones.

 

[David Mitchell]

I wish all DSLR sensors were like this but im guessing its not the cheapest to make!

 

[Pete Askew]

It s not without its faults - banding and colour artifacts in low light. Cost probably comes down more to volume than technical difficulties.

 

[Rob MacKillop]

Those b&w shots are stunning, ahmad.

 

[Ahmad Bhai]

Hi Pete, David, for me eventually, the benefits of Bayer that is high iso (although the latest Foveon does iso1600 rather well), and mirrorless swayed me away from Foveon. A mirrorless Foveon would be tempting, i would love to see top glass on a Foveon. As a camera for specific uses it can be something else and recent reviews of DP2M are rather enticing.

Having said this i think Fuji's Xtrans has fair amount of the "Foveon look".


Awwwww Rob u always say nice things about me fumbles

 

[Julian de'Courcy]

Ah in at last. Could not open this thread for some reason yesterday. Interesting on two levels as I had almost convinced myself to get the new DP2 Merrill, which carries the same sensor as the latest Sigma D-SLR offering. Looking across the web for images this sensor is different. The small DP2 M's output for landscape is extra ordinary competing on the levels of the large FF cameras. Will keep an eye out for any second hand ones. A relevant post for me Ahmad thanks.

 

[Rob MacKillop]

I was thinking the wide-angle DP1 Merrill would suit landscape better. No? Seriously thinking about one or tother myself.

 

[Pete Askew]

Probably, yes. The less wide version would probably suit me better though I think given that 35mm is pretty much my standard focal length at the moment and I usually crop the shots from the GRIII (28mm equivalent).

 

[Ahmad Bhai]

With the Foveon it is difficult to sometimes see why it can look a little different, perhaps more so these days with Bayer interpolation being so advanced and FF sensors as on the D800, D600, Apsc Xtrans of Fuji particularly to me the Fuji Xtrans giving a natural realism.
The discussion as to why Foveon can sometimes look somwhat different range from how light impacts the three stacked layers differently to it would one layer and each layer above impacting the layer below, to as there is no interpolation subtleties of colour, light, shade are retained (though Foveon colour cant always be said to be as netural as say Fuji colour).

In the colour images above the wooly mammoth looking tree on the left i have taken with Nikon 1D, Foveon just rendered the tree in a rounded dimensional. Similarly the second photo the foilage and trees have a roundedness which is rendered a bit flat with a one layer sensor.
Having said this much depends on the angle the photo was taken from, the light at the time and if it is natural landscape.
Natural landscape for me is where it is easier to see a Foveon although when posted online i cant tell the difference from Bayer.
I can tell the difference when i have seen the scene personally and photographed it.

 

[Ahmad Bhai]

Richard Franiec's Camera Accessories

Richard Franiec has released his custom grip for DP1M DP2M

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These two images i took with the original DP1 (2008). I hope they may show a little the subtlety Foveon is capable of.

DP1M DP2M sensor is likely to look more as DP1 than SD9 sensor. SD9 had a more organic look as did other sensors of that era.

 

[Pete Askew]

Thanks Ahmad. Hamish uses a grip by this guy on his Sony RX100 and I have ordered on also. If I go down the Merrill route I'd probably get one. Nice shots by the way. Very film-like I think.

 

[Rob MacKillop]

Those shots really do look like scanned film. Impressive.