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Brian DipertEDN Senior Technical Editor Brian Dipert exposes, analyzes and
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Friday, July 13, 2007

Sigma SD14 Dissatisfaction: Finally Believe Me, Foveon Fanboys?

Jul 13 2007 8:12AM | Permalink |Comments (118) |


I've written about image sensor supplier Foveon and its (currently only) camera OEM partner, Sigma, on multiple occasions: within two print feature articles ('Imaging Beyond Pixels: Enhancing The Elementary Picture' and one of its online addendums, along with the earlier 'Seeking clarity: Image sensors peer into a blurry future'), as well as in a number of blog posts. My consistent message has been that Foveon's Mpixel claims can't be taken seriously; that simply by embedding discrete red, green and blue spectrum-optimized photodiodes within each photosite (pixel), Foveon can't claim that they've tripled the sensor's resolution. This stance is especially valid when the alternative Bayer pattern sensor, whose proportion of red, green and blue filters synergizes with the human visual system's sensitivity to those portions of the visible spectrum, is as effective (in conjunction with interpolation, to create the missing remaining spectrum information for each pixel) as it's been proven to be over more than 30 years' worth of development and commercialization.

There's nothing like hard data to back up a theory-determined gut feel. Following up in their earlier initial hands-on impressions, Popular Photography has undertaken an exhaustive test of Sigma's latest SD14 camera (which I reported on back at PMA) and the Foveon '14.1 Mpixel' (4.7 million photosite) X3 sensor inside it, benchmarked against the Nikon D80 and its 10 Mpixel sensor. Both reports are excellent and I encourage you to read them in their entirety; to whet your appetite, I'll share a few choice quotes from the latter writeup's overview page below:

  • Black-and-white test targets for measuring resolution don't show as much detail as Foveon's 14.1MP count implies. Analysis of the IT-10 black-and-white resolution target we use in the Pop Photo Lab finds the Sigma SD14 on par with a good 8-9MP camera (in RAW mode), but not in the same class as 10MP models such as the Nikon D80.
  • Using a color spiral target that Foveon sent us for additional tests, we found the SD14 captures slightly more detail in red-and-blue areas than the Nikon D80 -- but not in the target's black-and-white or dual-color areas that contain green. So, in real-world shooting -- where it's hard to find finely detailed red-and-blue subjects or scenes that have little green or b&w detail -- the D80 has the sharpness advantage and outperforms the SD14 at high ISOs.
  • Foveon and Sigma are right in saying that color moiré in very fine detail was a problem in early digital cameras using Bayer pattern sensors. However, most manufacturers now use low-pass filters and image processing to minimize or eliminate moiré. The loss in resolution goes unnoticed because of higher pixel counts.
  • RAW data from the X3 sensor still seems to require intensive (not minor) postprocessing to convert color information into the final image. And more processing translates into a slower burst rate on the SD14 compared with other DSLRs. In-camera JPEG images from the Sigma SD14 also show less color accuracy and detail than RAW files processed by a computer. (Editor note: sorry, Analog Devices, better luck next time....)

This quote's my favourite, and from the camera review:

  • We discovered, though, that the 14MP Super Hi JPEG format is merely an interpolated version of the 4.7MP Hi Quality JPEG, taking up much more storage space without offering a significant image-quality or print-size advantage.

Granted, the resolution captured by a camera is a complex combination of multiple factors, not just determined by the image sensor specifications, as imaging guru Mark Schubin has explained on numerous occasions (most recently in an outstanding writeup in Videography magazine). It's possible, for example, that the SD14's optics are holding back the Foveon sensor potential....but given that Sigma's first and foremost a lens manufacturer, I frankly find this particular hypothesis to be quite doubtful.

You've previously read my thoughts on Foveon. Now you've got the supportive statistics. I rest my case. Comments, folks?

p.s....speaking of sensors, and the gadgets containing them, check out the thought-provoking discussion 'Digital Camera vs. Camera Phone' that recently appeared on Slashdot.

Followup: Nothing beats a price cut when striving to stimulate sales, I guess, although in comparison to deals like this one, the SD14 still seems way overpriced to me.

Reader Comments



at 7/13/2007 10:07:38 AM, Curious said:
So ... if more samples per pixel location do not improve image quality, why is it that the highest quality video cameras use three sensors and a prism?



at 7/13/2007 10:49:38 AM, Brian Dipert said:
Dear Curious, I never said that three samples per pixel doesn't improve image quality, but there is a tradeoff....the Foveon sensor is effectively only 4.7 Mpixels in resolution, whereas 10 Mpixel Bayer pattern-based CCD and CMOS sensors are now prevalent. And to answer your question, videocams use a three-sensor prism arrangement both to improve image quality and to improve low-light sensitivity. However, this is (of course) a much more expensive, bulky and power-hungry approach compared to the single-sensor Bayer or derivative technique



at 7/13/2007 6:09:49 PM, Josh said:
Bayer cameras use over half of there "mega-pixels" for resolving power...a ten mega-pixel bayer camera isn't really a ten mega-pixel camera, just like the SD-14 isnt a true 14 mega-pixel camera.



at 7/15/2007 1:24:56 AM, Laurence Matson said:
You state:
". . . that simply by embedding discrete red, green and blue spectrum-optimized photodiodes within each photosite (pixel), Foveon can''''t claim that they''''ve tripled the sensor''''s resolution."

Could you please cite one piece of literature from Foveon claiming that they have "tripled the sensor''''s resolution."? Remember, resolution is the operative word in the above.

And while you are at it, please explain how spatial locations are related to resolution. (That might be easier.)

Finally, since you are a big reporter at PMA, you obviously missed the amazing video presentation by Foveon at PMA 2005!



at 7/15/2007 3:06:03 PM, Brian Dipert said:
Dear Laurence Matson, peruse (for example) the Wikipedia definition of 'pixel'. Both in the image capture and image display realms, common and longstanding industry convention refers a pixel as 'the smallest complete sample of an image'. The word 'complete' is key here, as is another portion of the Wikipedia essay; 'in color systems, each pixel has typically three or four dimensions of variability such as red, green, and blue, or cyan, magenta, yellow, and black.'

Now look at the X3 Technology overview writeups on Foveon's website. Foveon has long attempted to redefine 'pixel' to mean an image capture element, convenient because in doing so it enables them to effectively triple their sensors' claimed pixel counts (i.e. their 'resolution', again referencing common and longstanding industry convention reference of the term). I'll directly quote one example of Foveon's attempt to rewrite history for you (reference: www.foveon.com/article.php?a=68): 'A pixel on the image sensor of a digital camera is a light absorbing element (photodetector) that converts light (photons) into electrons. A pixel is also referred to as a pixel sensor when there is a need to distinguish the pixel from its location. A pixel location is the X,Y coordinate on the two-dimensional grid of an image sensor at which the pixel is located.'

This is absolute rubbish. We don't refer to the red, green and blue sub-elements within each LCD pixel as 'pixels', we refer to them as sub-pixels. Similarly, it makes no sense to refer to the red-, green- and blue-tuned photodiodes within each Foveon sensor pixel as pixels in and of themselves....call them subpixels, if you wish, but NOT pixels. I've never disputed the fact that Foveon's approach MAY provide more accurate color than a Bayer patterned-sensor of equivalent pixel resolution. But is Foveon's latest X3 sensor '14.1 Mpixel' (reference: www.foveon.com/article.php?a=222)? No, I've consistently said. And Popular Photography has just confirmed my stance. End of story.



at 7/16/2007 2:17:08 PM, Cristian Oltean said:
I would not use Wikipedia as a technical reference. And the definition ''''the smallest complete sample of an image'''' has no meaning. It may get one in a different form like ''''the smallest complete independent sample of an image''''. Independent is the key here.
This is why interpolation is not accepted as a method to increase the real resolution. Because pixels would be no longer independent. But then not even the professional cameras deliver fully independent pixels there is always some blurring.
And now the big question: how much cross-correlation is acceptable between adjacent pixels?



at 7/16/2007 5:31:09 PM, Brian Dipert said:
Dear Christian, I'll requote from Popular Photography's writeup, which echoes comments I've made several times in the past: "Foveon and Sigma are right in saying that color moiré in very fine detail was a problem in early digital cameras using Bayer pattern sensors. However, most manufacturers now use low-pass filters and image processing to minimize or eliminate moiré. The loss in resolution goes unnoticed because of higher pixel counts." Now granted, if you do a wall-sized enlargement of a tiny portion of the original image, you might still see a per-pixel color accuracy difference with a Foveon sensor-based camera versus a Bayer pattern alternative....but then again, I'd argue you'd be much less likely to do such a thing with a Foveon-based camera because of its inherently lower pixel count! And I agree with your fundamental distaste of interpolation, by the way....I've never been a fan of 'digital zoom' (as my writeups have, I think, made clear).



at 7/18/2007 8:55:46 AM, Michael J. McNamara said:
Brian:
As the author of the report (s) in Popular Photography and Imaging, I''m of course pleased to find someone who agrees with my findings. I''d only add that I think both Foveon and Sigma did themselves a dis-service by hyping the pixel counts as they have for both generations of X3 sensors. The fact is that for a 4.7MP layered-sensor the current one in the SD14 resolves at the equivalent level of an 8-9MP Bayer-pattern sensor, and it records some color details better (but not all). Why couldn''t Foveon just promote that fact and not try to "rewrite history"? By the way, Foveon attempts to rewrite history again on its web site with the following quote: "For over 100 years, color film has traditionally been held as the gold standard for photography. It produces rich, warm tones and incredible color detail that consumers around the world have become accustomed to. Film has achieved this by using three layers of emulsion to capture full color at every point in the image." WIthout even checking my Focal Encyclopedia of Photography I can tell you that color film hasn''t been around for 100 years. But that encyclopedia gives credit to Kodak in 1935 for the intro of Kodachrome as the first commercially viable color film. Prior to that, color photography and printing relied on screening and filter techniques that recorded separate color data on panchromatic film and required precise registration in both capture and printing. That is actually a process that it closer to mimicking the Bayer Pattern!
My test of the SD14 also pointed out the failings of this camera and sensor at higher ISO''s (above 400) just as my tests on the original SD9 pointed out its failings in exposure latitude compared to typical CCD and CMOS sensors. For the price of the camera, these performance problems made it non-competitive with other cameras such as the Nikon D200 or Canon EOS 30D.



at 7/18/2007 2:05:02 PM, Rick said:
In the Analog Devices press release link ("sorry Analog Devices"), Sigma COO Yamaki states the "SD14 tells the ''whole truth'' about an image, by capturing the real color of every pixel." That can be interpreted either the pixel captures the real color (which would take the 3 subpixel elements) and would be a 4.7 MP camera, or each element captures the real color. The second interpretation would be inaccurate in that only one portion of the real color is caputured (red, green, or blue) and not the true color.
Looking at the Sigma website, they would seem to pull back from the pixel count argument by saying "it''s not all about the pixel count" (philosopy section). But then they go on and say "Its high image quality comes from 14 megapixels" so maybe they are hung up on pixels.
Sounds like they are trying to play the megapixel marketing game that people seem to buying. Pixels shouldn''t matter as long as there are enough of them to give good resolution for the task and the image looks good.



at 7/26/2007 9:08:07 PM, John Clifford said:
Using ''''pixel'''' to refer to resolution is invalid, because a pixel is the final ''''picture element'''' that is the result of interpolation from the raw Bayer sensor data. All Bayer images are interpolated, which is a fancy way of saying ''''the result of guesswork'''' and it is a credit to modern software engineering that interpolation routines guess as well as they do. Therefore, an interpolated 10 MP JPEG image from a Bayer sensor no more reflects 10 MP of true resolution than a 14 MP Foveon JPEG image from the SD14 reflects 14 MP of true resolution. Interestingly enough, though, a 4.2 MP image from a Foveon sensor has about the same amount of resolution as a 10 MP image from a Bayer sensor... because the smallest item that can be resolved by a Bayer sensor spans a circle that has to hit at least four adjacent ''''pixels'''' (photosites) on a Bayer sensor, while it only needs to span a circle that hits a single ''''pixel'''' (photosite) on a Foveon sensor. The best term to use to discuss image sensor resolution is ''''photosite'''' which is the smallest sensor area that can detect detail



at 7/26/2007 9:15:57 PM, John Clifford said:
The best term to use to discuss image sensor resolution is 'photosite' which is the smallest sensor area that can detect detail; on a Bayer sensor it is comprised of four adjacent photodetectors (incorrectly referred to as sensor pixels) arranged in a 2x2 horizontal matrix, the photosite area being a circle that spans the 2x2 matrix. On a Foveon sensor, a photosite is comprised of three vertically stacked photodetectors with the sensor area of a single photodetector. I agree that Sigma's resolution claims (14 MP) are misleading, but so are the resolution claims put out by the various camera manufacturers using Bayer sensors. In the end, what counts is results, and the Sigma SD14 equals and often exceeds its 10 MP Bayer competition in real-world (not black and white resolution target) resolution tests. I eagerly await the next generation of Foveon sensors, and wait for the day that a full-frame 8 MP Foveon dSLR sensor is introduced; it will blow away everything else in the dSLR market including the 16 MP Canon MkII.



at 7/27/2007 12:13:42 AM, Laurence Matson said:
Brian, in your long comment here:
at 7/15/2007 3:06:03 PM, Brian Dipert said:

You did not answer any of the questions asked. You don''t have to humor me with lengthy discussions on pixels with all kinds of cites to Foveon and Wikipedia. I probably know all of that at least as well as you if not better.

But why not address the question, which was, again:

at 7/15/2007 1:24:56 AM, Laurence Matson said:
You state: ". . . that simply by embedding discrete red, green and blue spectrum-optimized photodiodes within each photosite (pixel), Foveon can''t claim that they''ve tripled the sensor''s resolution." Could you please cite one piece of literature from Foveon claiming that they have "tripled the sensor''s resolution."? Remember, resolution is the operative word in the above. And while you are at it, please explain how spatial locations are related to resolution. (That might be easier.) Finally, since you are a big reporter at PMA, you obviously missed the amazing video presentation by Foveon at PMA 2005!

Specifically, what do pixels have to do with resolution? Where does Foveon state that they tripled the resolution? And while you are at, could you please explain why there might indeed be some advantages to this approach in the form of luminance and chroma resolution?

If you were truly curious about pixels and definitions, you would delve into the source material from the defining bodies and not run around Wikipedia. Also, Dick Lyon''s lecture on pixels given at Google is an excellent starting point for the open minded on coming to terms with this defining pixel. Since I suspect that you make your micro-bread more by taking a stance and sticking to it than really digging into the subject and perhaps coming to a different conclusion from that at the starting point, I guess that you will just stand behind to CFA barriers in your mind and keep those clicks coming. But I am willing to be surprised.



at 7/27/2007 1:33:19 AM, Robert said:
Wikipedia isn''t always reliable, but in this case their definition of pixel is consistent with everyone elses definition, except Sigma and Foveon of course. Pick any engineering textbook or Google for it. Laurence, you''ve been thru this debate in various other forums and you still refuse to accept the correct definition. Why?

The sensor has 4.7 million pixels. Calling it 14.1 million is tripling it. I''m not sure how much clearer it can get.

Sigma originally called the SD-9 a 3.4 megapixel camera, but after low sales they tripled it it to 10.2 megapixels with the SD-10. The sensor didn''t change (other than microlenses). The difference was nothing but marketing. There is no technical reason for that (ask any engineer).

I also must point out that Bayer does NOT guess at all. It accurately calculates the missing information and it can accurately resolve finer detail than a 2x2 grid. Foveon also calculates RGB from its three samples (which aren''t pure RGB), and its a more complex calculation than Bayer. Why isn''t that called ''guessing'' ?




at 7/27/2007 2:03:44 AM, Guido FORRIER said:
The sd14 foveon has 4,7 million pixels for all the colors . A bayer 10mb has 5 million for green , 2,5million for blue and red .




at 7/27/2007 6:41:24 AM, Mike said:
I find this a rather bold article for someone who (apparently) has not even held the SD14 camera and is just picking up some random pieces off the internet. Sigma would have gotten blasted on "pixel" count no matter which way they cut it. It doesn't matter how you define "pixel", the fact of the matter is that the Foveon technology is different so something isn't going to match. Mr. Dipert chose to use the Wikipedia definition of pixel, so let's stick with that. By that definition of pixel, Nikon shouldn't be able to claim 10 megapixels for a D80 either because there isn't a single photosite on the sensor that is complete! See where I'm going with this? Had Sigma used 4.7 MP, something would have been lost in the translation. They use 14 MP which is also not a good/accurate term but had they used 14 megasensor, 14 megadiode, or even 4.7 megapixels x 3 layers, people would have no idea what that means without having to read an article. In my eyes, Sigma/Foveon were damned if they do, damned if they don't. And your statement about Bayer cameras being refined over the years is true, but certainly not a valid negative for Foveon. Bayer has been around for years too with video cameras but it is a well known fact that 3 chip video cameras perform better. Replicating the DEFICIENCIES of the human eye is not a good thing! The goal of digital photography should be to produce the most accurate result possible of the original scene and (good) full color capture will always perform better than Bayer for that purpose. Where the equivalency is and whether a 4.7 MP full color capture sensor is a good match for an 8, 9, or 10 MP Bayer sensor, that gets a bit more complicated.



at 7/27/2007 7:14:46 AM, Sean said:
As a bayer user, i have been very intrigued by the potential of the Foveon technology. Bayer has very visible shortcomings in what I would call "hard color" transitions (like red to white). You can see a noticeable drop in image detail at these transitions. On the other hand, these transitions are not all that common and are not easy to see if you are not looking for them. There is alot of mis-information spread around in these discusions (my favorite lie is that bayer cameras use 4 photosites to make 1 pixel, giving you 25% resolution). The truth is that the SD14 is a true 4.7mp camera, while a 4.7mp Bayer camera would not provide the same amount of detail. The problem Foveon has is that they are not competing against 4.7mp cameras, they are competing against 8 and 12mp cameras.



at 7/27/2007 7:49:20 AM, Brian Dipert said:
Dear Robert, I wasn't aware of the resolution spec inflation (with no change in underlying sensor) that paced the SD-9 to SD-10 transition. Thanks for the historical data; that's a classic!



at 7/27/2007 8:07:32 AM, Ed_S said:
Dear Brian,

As this is my first exposure to your work I have limited basis for evaluating its scientific or photographic worth. I must politely comment that as I read this article and the various comments/responses, I'm a bit put off by your apparent "agenda". The very tone of the title is offensive IMHO to any satisfied user of Sigma DSLRs and if you will "poisons the well". If you have to say "fanboy" you are not objective. You make several worthy observations to include the point that 4.7M x 3 may not be 14M effective megapixels. Many knowledgeable as to Sigma/Foveon technology would agree, but would counter as has at least one reader that 14M of bayer really doesn't produce 14M of resolution. Coupled with that, your arguments rely (apparently in this article) primarily on secondhand theory and opinion to include the less-than-unbiased evaluation in Popular Photography. As a user of Bayer, Foveon, and even 3CCD equipment, I welcome a scientific and unbiased discussion which sets out to present fact as best current science knows it. I'm afraid that your article at best sees the world through a Bayer sensor. Or so it seems to me.



at 7/27/2007 11:45:29 AM, Peter Spader said:
The pixel count problem arose due to the fact that the conventional way of sizing sensors does not take into account the vertical stacking (VFA) Foveon used. Initially Foveon tried to indicate the difference my simply adding X3 (time 3), but people started classifying the SD9 as just a 3.4mp camera, so Foveon did the multiplying and called the SD10 a 10.2mp camera and the SD14 a 14mp camera. Given the fact that a case can be made that the CFA (aka Bayer) is not truly an Xmp camera, we really do need a common designation everyone can agree to. This will be hard enough from a technical point of view, and once the marketeers get involved almost impossible

The more general problem is trying to come up with a fair way of comparing the Foveon/Sigma cameras with the CFA (aka Bayer) cameras given just how different these two approaches are. Take resolution (only one element of IQ), for example. The conventional B&W resolution charts do not work well, and the various attempts to come up with alternatives have not yet gotten to the point where everyone agrees. Furthermore there are other factors in IQ resolution does not address.

Which leaves us with the “subjective” reaction to the images themselves. I personally find the Foveon images captivating in a way the CFA images are not and have taken part in some of the discussions trying to find out why. There are a number of factors that have been suggested, some of which are not just “subjective,” but again, we are not yet at a point where everyone agrees.

At the same time I have never suggested the best CFA images are not very good indeed. I am less interested in the “which is best” debates since they often raise the number of variables to the point where the whole debate becomes a set of crossed monologues. To the degree they explore new ways of making comparisons they have some value, however.

BTW, ad hominem does not help much either. I am a fan of IQ, but at the age of 68 I am no longer a boy, and if Fan Boy is meant to suggest I am uncritical, that too is inaccurate. Given the hope that we are all interested in the furthering of “the catching of light,” as some called photography, lets keep the debates focused, please.




at 7/27/2007 11:51:43 AM, John Clifford said:
How can a Bayer CFA sensor calculate the color on the area of a single photosite, when that single photosite has a color filter that blocks two of the three primary colors? By looking at adjacent photosite data, and GUESSING that, based upon a very complicated algorithm, given a certain data value at this and adjacent photosites an assumption can be made that the color at this particular photosite is "X". Any change in color that is too small to hit at least three adjacent photosites is subject to miscalculation, i.e., a bad guess. The Foveon approach, on the other hand, has three separate color-sensitive photodetectors in the same area (because they're vertically stacked). Therefore, changes in color that hit a single photosite are detectable... unlike with a Bayer sensor. Want proof? Take a 50mm M42 lens with an EOS adapter, put it on a Canon 5D, and take a picture. Put the same lens, with an SA adapter, on an SD10. A 2268x1512 center crop out of the 5D's image will be identical to the image from the SD10 in terms of image coverage because the photodetector (pixel to you non-technical types) size is almost identical. You will notice that fine detail which cannot be seen on the 5D image is clearly visible on the SD10 image. Why? Because the 5D's image processing algorithm guessed wrong, and because the SD10's image processing algorithm didn't have to guess.



at 7/27/2007 11:55:30 AM, John Clifford said:
BTW, if you really don't think Bayer CFA sensors guess, then I have just one word for you... MOIRE.



at 7/27/2007 12:42:23 PM, Walter said:
I''m not convinced that Sigma is right to use these pixel counts - but they aren''t the ones who started mis-leading the public - and their action is certainly as fair as those of the Bayer crowd. In *any* other application, like an LCD screen for example, a pixel is made up of red, green, and blue elements. You don''t call your 1024x768 LCD panel 3072x768 or 1024X768x3 - though any current camera company would - the first is what Bayer cameras do, and the second what Sigma is doing.

That''s right. Bayer MegaPixels are just wrong. 2/3rds of the information in every output pixels is an interpolated guess. This is where Moire comes in, and the reason you have to sharpen Bayer images, either in camera or in development - your "native" resolution is substantially interpolated to begin with. The fact that sharpness varies in a natural, optical fashion creates the "3D" look of the sigma, which Bayers can only achieve by downsizing.

So Sigma gave an honest 3.4 megapixels to the SD9 - and the world ignored it because the Bayer crowd was providing a dishonest 6-8 MP and the same time. (which the SD9 generally out resolved.) In choosing to call the SD10 "10 megapixel," they only committed the same deception that all other digital cameras have except for the few monochrome models out there.

I don''t generally consider myself a "Sigma Fanboy," but the answer to your question is no, I''m not at all convinced. The Sigma rating is at least as accurate as that of competing Bayer Cameras, and test pictures from a dozen sources show it matching resolution with Canon''s magnificent 5D on even terms. (Note, pictures, in the real world, not B&W test charts that favor the asymmetric color resolution of a Bayer sensor.)
Walter



at 7/27/2007 3:35:07 PM, Kendall said:
1) Color processing is not done in-camera (unless you shoot JPEG). And JPEG images write out quicker to a CF card than RAW (because there is less data). You need a new theory on processing time for color conversion.

2) No red & blue subjects in the real world? What about just about anything with fine detail against the sky? Or red cars? Or Fall leaves against a blue sky? Or Red boats in the water? It doesn't take much to think of many things that come across being helped by red & blue resolution enhancements. But even green is helped, which you can see when looking at foliage details like distant leaves or blades of grass.

3) If it's really a 4.7 MP camera, how is it that it has the same evident detail as a D200, or even a 5D in some cases when enlarged? The problem is you are using a fixed number from a bayer camera that represents a variable level of output quality, to try and compare against a fixed number on the SD-14 that represents a fixed amount of detail captured regardless of color content. Anyone can take a look at any one of numerous full-size SD-14 images (such as on www.pbase.com) and see there is more data there than a 4.7MP bayer camera - by stating this you only hurt your own credibility.




at 7/27/2007 3:42:03 PM, Kendall said:
Robert: What the Foveon chip does is not guessing, because for any given location on the image it has the full spectrum of data availaible. If anything the process by which it determines color could be called "untangling" because there is some overlap between the three sensors - but because there is no break in data there is no "guessing" to be done.
<p>
As for pixels, you are confused because camera sensors use "photosites" to capture data that are converted into the "pixels" you see on screen.




at 7/27/2007 4:45:57 PM, Alf Beharie said:
Brian, the problem is you are trying to think of Foveon sensor pixel count in a Bayer sensor pixel count mindset, whilst not understanding how Bayer pixelcounts are wildly over exagerated for no other reason that to help sell more cameras...Here is a quote direct from reference.com, the online encyclopedia, which should help you understand that Foveon pixel counts are just as valid and accurate as those used for Bayer sensors:
"In contrast to conventional image sensors, the Foveon X3 sensor uses three layers of sensor elements, so that it detects red, green, and blue intensity at each array location. This structure eliminates the need for de-mosaicing and eliminates the associated image artifacts, such as color blurring around sharp edges. Citing the precedent established by mosaic sensors, Foveon counts each single-color sensor element as a pixel, even though the native output file size has only one pixel per three camera pixels. With this method of counting, an N-megapixel Foveon X3 sensor therefore captures the same amount of information as an N-megapixel Bayer-mosaic sensor, though it packs the information into fewer image pixels, without any interpolation."



at 7/27/2007 6:14:06 PM, Oliver Nielsen said:
How the Foveon sensor compares, when shooting spirals and charts in a lab is of little interest to me, as I pride myself in LOOKING with my EYES on PICTURES of REAL OBJECTS, and judge the camera on that.




at 7/27/2007 6:21:51 PM, Oliver Nielsen said:
What's good is, all this anti-hype against Foveon is actually good advertising pro-Foveon and Sigma. I became a Sigma SD14 user last week, partly because of reading all these discussions and then playing around with some of Carl Rytterfalks RAW files.

I could have purchased a Canon 30D instead but really don't like Canon's porky, flat, two-dimensional take on skin tones. The Sigma's images are not perfect, but they do have that depth I missed since selling my Pentax 67 on eBay.

You want Canon? Get a Canon. You want Sigma? Get a Sigma. Nikon? Go ahead... In the end, I feel confident my Sigma will give me the results I need. Could those results be achieved with a Bayer based camera? Yes, but I feel Foveon gets me there faster and better.

Photography is about personal expression. Then for gods sake let the tool chosen be a personal choice of the individual. Being a photographer is not organized religion.



at 7/27/2007 6:33:11 PM, Brian Dipert said:
Dear Oliver Nielsen, I'm still holding onto my prized P67 and its lens suite and other accessories....and the film for it (from a Roseville, CA photographer who 'went digital') is sitting in the freezer awaiting my attention!



at 7/27/2007 7:28:07 PM, Robert said:
There is no change in pixel count by having multiple layers per pixel. None whatsoever. Bayer does not guess pixels, it calculates them, as does Foveon, but with different formulas. Moire is not caused by guessing, it is from alias artifacts, which on a Bayer sensor are colorized (and rare). Sigma cameras have no anti-alias filter so there are a lot more artifacts (but not colorized), which many people confuse for more detail. Sigma also sharpens the image more than other cameras. Not a fair comparison, but it does have a unique look. Comparing SD10 to 5D and cutting out almost all of the 5D image is absurd! What kind of crazy biased test is that? This page is linked at the Sigma forum at dpreview and they are having a field day with it, which is why there are a lot of comments suddenly.



at 7/27/2007 11:35:45 PM, John Clifford said:
Robert, you do not, and cannot, explain HOW a Bayer sensor-equipped camera calculates the RGB value of a final pixel (picture element) based upon a monochromatic image sensor pixel (photosite). The fact is, it interpolates, i.e., GUESSES. Now, the guess is a very educated guess, based upon the values of adjacent photosites, but it is STILL a guess, and that fact that the guesses are right far more often than wrong is a tribute to smart software developers. When the camera gets it wrong, then you get wrong colors, or in the extreme you get MOIRE, a.k.a. INCORRECT GUESSES, a.k.a. alias artifacts. The Foveon sensor doesn't have to guess since it can sample each primary color at the same photosite, thus detail only becomes ambiguous when it spans less than a photosite. The same is true of a Bayer sensor, but the photosite area is greater than individual photodetector (pixel to the ignorant) area, and thus for a given photosite density the Foveon will resolve greater detail. The cropped 5D to SD10 comparison IS a fair comparison AT THE LEVEL OF THE INDIVIDUAL PHOTOSITE and shows how you get more resolution for the same image area, given the same photosite size, on a Foveon sensor versus a Bayer sensor... no one is saying that an SD10 has more photosites, but that the resolution on a per-photosite basis is noticeably better. And finally, the default Sigma SDx image format is RAW (X3F), and no sharpening is applied.



at 7/28/2007 2:38:21 AM, Alf Beharie said:
The man who conducted that SD14 vs Canon EOS 5D comparison you refer to did not cut out any of the 5D image to match the crop of the SD14.
I think you will find that he actually used a wider lens on the SD14 so that the FOV's were virtually indentical (SD14 + a 50mm lens x 1.7 crop=85mm vs 5D + 85mm lens=85mm)and then he upsized the resulting SD14 shot to match the size of the 5D shot which gave the 5D something of an advantage yet it still could not capture fine detail in greens as well as the SD14.
If you think the methods employed in some way biased the result in favour of the SD14 personally I think you will find its the opposite but if you dont agree why not contact Mike Chaney yourself with your concerns?



at 7/28/2007 2:58:34 AM, Walter said:
Robert, I get the feeling you''re missing our point here. Yes, all cameras do calculations to determine values for every pixel. The Foveon takes 14.1 million values, and ends up with 14.1 million values (4.7 million locations x 3 colors each) By contrast, the Canon 5D starts with 12.7 million values, and ends up with 38.1 million (12.7 million locations x 3 colors each.) This interpolation is a little different from up-ressing a picture - but the results are similar. And this interpolation is the reason you have to sharpen a Bayer image.

I''d like to see you find any authoritative source that says the Sigma sharpens more. The fact is, it doesn''t - and it doesn''t have to, because the Sigma isn''t making a larger image than it has information for.

Yes, it is referenced on the DPR forum - but wasn''t that the point? After all, the article is addressed to the "Foveon Fanboys" - so shouldn''t the experienced owners at the Sigma forum be given a chance to comment? The fact is, most Sigma owners understand the situation and questions better than anyone else... We''ve had Bayer cameras, and Foveon cameras, and know what hey do in the real world. Several of us have and occasionally shoot Canon pro bodies - but for some applications, they still prefer the Sigma cameras.

Walter



at 7/28/2007 7:22:49 AM, George Preddy said:
Brian, I think you will just have to accept that people will use whatever appeals to their own eyes. I myself shoot with Canon, and constantly hear comments (even on this blog!) about ''plasticly'' skin tones from those cameras. I think this is rubbish personally, but I respect that my eyes are not infallible - perhaps there is something there that I cannot sense, or ''pickup''?




at 7/28/2007 7:28:53 AM, Brian Dipert said:
George, the 'plasticky' feedback you've gotten sounds akin to an argument that an audiophile would make, in justifying his or her multi-thousand-dollar speaker wire ;-) As for me, as you say with your Canon gear, I'm pretty darn happy with my Pentax and Samsung 6/10 Mpixel DSLRs. Hey, if you can't see 'plasticky' artifacts (putting aside for the moment whether or not they're even there), then why spend extra money to deal with them?



at 7/28/2007 10:01:00 AM, Doug said:
You are missing the point. The true test of a camera is its ability to produce image quality. The argument about mega pixels, is it and isn''t it and so forth, is irrelevant.


Red



at 7/28/2007 12:48:18 PM, Super-Genius said:
It has 14MP. A low pass filter reduces resolution anyway. The SD14 is a stinker because the sensor is too small and noisy, the color reproduction is not professionally salable, the body is way too slow when saving images, the LCD screen is a cheap toy, the lens mount is weak, the flash metering is Neanderthal, the software is buggy, and the price is double what it should be. Other than that it's revolutionary.



at 7/28/2007 1:55:38 PM, Robert said:
Alf - I'm referring to John Clifford's test where he clearly said "A 2268x1512 center crop out of the 5D's image will be identical to the image from the SD10 in terms of image coverage." John - I write image processing software and can precisely explain how Bayer works, but this is not the place for it. Suffice it to say that your understanding is not correct. Walter - Sigma PhotoPro sharpens by default when set to 0. Common knowledge among Sigma users. Other cameras 0 sharpening means 0 sharpening. Also, the bottom layer of Foveon has a little sharpening applied separate from the SPP setting.




at 7/31/2007 3:47:49 AM, John Clifford said:
Robert, I have written image processing software, and again I ask you to tell me how you can accurately determine the color at a single 'pixel' based upon a monochromatic value... and the answer is, you can't. That is why (and because) Bayer image processing algorithms MUST look at the values of adjacent 'pixels' in order to determine what the 8- to 12-bit number indicating relative light strength actually MEANS at that location. Re the center crop test... I did this test, and found that, yes, because the 5D shared a 'pixel' diameter of almost exactly that of the SD10, then a center crop from the 5D would be almost identical in scene coverage to a full-frame image from an SD10 given the same lens. In other words, IF the SD10 was a full-frame sensor instead of a 1.7x crop factor APS-C-sized sensor, it would have the same number of 'pixels' as the 5D. Capiche? Therefore, comparing such images is valid for determining PER-PIXEL RESOLUTION, not camera-to-camera resolution. Per-pixel resolution comparisons are a valid way of evaluating the merits of Foveon versus CFA technology (as opposed to SD10 versus 5D), and the Foveon design wins as expected. The 5D will outresolve an SD10, as well as the SD14, but the latter comes a lot closer in terms of actual captured resolution (versus 'pixel count')... and the per-pixel resolution shows that, again as expected, a 2x2 multi-row panorama that provides 12 MP of Foveon sensor area greatly out-resolves a single image with the same number of MP from the 5D. In short, all of the bashing the SD14 has received on this blog is irrelevant, since Sigma acknowledges that it didn't set out to build a camera that would compete on features with the D200, 5D, etc., but one that would compete in terms of image quality... and they did. The D200 has better AF, better TTL AE, etc., but given proper exposure the SD14 has better image quality.



at 8/5/2007 7:01:22 PM, petr petr said:
Did someone made simple shot of red cardboard for example?
Sigma with latest foveon should be recording 4.7mpx single colour,correct?
And what about bayern system people?
Try that and will see!!!!!!!!



at 10/6/2007 9:57:38 AM, Mr. Nmptlpt said:
Some like Ectachrome, some Kodachrome. I always liked Agfachrome 50. I developed my Tri-X in D76 or Acufine and printed "down with contrast," grain and all.

I like the results of the SD14 and there are some wonderful programs like PhotoZoom for enlargements. Frankly, I think too many of you out there are "spoiled rotten." Compared to what we had even as little as 30 years ago, we are in the midst of a technical revolution that has rocked such giants as Kodak. The SD14 provides results that are, INM”H”O vastly superior to film, especially in the light of softwear like PhotoShop, DXO and PTGui. Just think of it, we can now buy software that makes our electronically rendered photo look like, you guessed it, Tri-X, Velvia, Sepia or Kodachrome. Some of the best photos were made with Brownies

So let us (notice, I include myself) stop whining and start making Photgraphs!




at 10/6/2007 10:18:13 AM, Mr. Fanboy said:
Dear Mr. Expert,

"Sigma SD14 Dissatisfaction: Finally Believe Me, Foveon Fanboys?" Why should I believe you? There are other like Mr. Mike Chaney, also an expert who might differ. Me thinks thou protest too much!

Isn''t that a bit Cavalier to the point of self-appointed "guru-dom?"

Yours truly,

Mr. Fanboy




at 11/3/2007 9:11:50 AM, Robcad said:
To this Brian Dipert and what's the other guy's name... ah McNamara yeah. please read www.ddisoftware.com/sd14-5d/
and then realize that things are a little bit different than what you stubbornly think...
Regards,
robcad



at 12/16/2007 11:55:26 PM, Derek said:
It is mid Dec 2007 now, and Poor Robert is still trying to work out how to explain that: "Bayer does not guess pixels, it calculates them". Robert, if indeed you "write image processing software and can precisely explain how Bayer works" (if so, may God have mercy on us all) it should be trivial for you to answer that one. I am sure that you are a busy person, so how about a link to a place where YOUR software which can uniquely do such miracle is explained in a bit more details... any technical articles, patents, presentations, journal articles, anything? No? Great pity, for the photographic industry your method of being able to accurately determine the color at a single ''pixel'' based upon a monochromatic value (no guessing! accurately!) would be revolutionary (and for you personally it would bring a lot of rewards, including $$!).



at 1/13/2008 11:13:29 PM, Don Ferguson said:
Look at the title of this post!! And then everyone of your reponses call on popular photographers Mr. Mcanara for backup.
You two should get married and live unhappily ever after.
There is simply no room for the likes of you in this sofisticated world we all live in now.
This type of bias simply has no place in the world where we are all trying to get to the real truth where we simply aren't going to get it from manufacturers so we rely on reviewers, but to use words like fanboys! you have shown yourself to be an idiot.
Your whole take on this is simply an insult to any intellegent person!
I simply hope that your publishers or superiors will usher you out the door and replace your xxx with someone of some integrity!
Don Ferguson



at 4/13/2008 8:32:56 PM, Sam Murphy said:
When Sigma/Foveon first came to market, they promoted their megapixel count with reference to only the single layer count, and attempted to educate the public about the differences between foveon and bayer. Later, they began to use the full 3 layer count as they believed (and rightly so) that people were not fully understanding the complexity of the foveon architecture and belived they were getting short changed. Even the author of this article would agree that the foveon sensor resolves more than it''s single layered bayer counterpart, eg. the 4.7MP foveon would out resolve a 4.7MP bayer, however, because of naming/counting conventions, the foveon get''s short changed (from a marketing point of view). If you were to do such a comparison, the bayer sensor would be put to shame, in part because of it''s interpolation, and in part because of its sharpness robbing anti-aliasing filter. Simple mathematics explains the differences in resolution among the colours: a 10MP bayer (eg. the Nikon D80 popphoto uses) has 2.5MP blue, 2.5MP red and 5MP green. So of course, it does better with green, and worse with red and blue, which is precisely the results popphoto came up with. I agree, Sigma/Foveon should not claim a 14MP sensor, but is it fair that they be handicapped so much (popphoto, as you quoted, give the foveon 8-9 MP resolving power), simply because naming conventions do not allow for their sensor design?



at 5/17/2008 11:02:15 AM, wuzabeeb said:
Excellent discussion .. from a broadcast video background and working very much in HD at present .. it seems that the main area ignored is that the lens puts down image detail accurately on to a sensor surface that is - in the case of Foveon - doing what film does and producing single location colour accurate results .. whereas Bayer sensors are location shifting the optical image colour information .. so will produce output that is more 'testing' of the lens capability, especially as we approach higher pixel counts on finite area surfaces of sensor. We also have to take into account the 'post processing' that is essential to bring correlation of the colour information on Bayer sensors. Pixel shifting works on video cameras.. but leaves a less than satisfactory impression of 'resolution lost' along the line somewhere.
I think the marketing 'hype' regarding pixel 'resolution is something that it is good to see challenged .. but commonsense tells us it's only a matter of time before the sensors exceed the resolution of 70mm film .. and then we all relax?

In the meantime ... a '14' MP Foveon sensor working in 'native' mode produces a much smaller file than a 14MP Bayer sensor yet only a fraction less resolution ..according to the tests ... surely this should be the correct comparison to look at?



at 6/25/2008 6:09:18 PM, stedwards said:
maybe late to the party, I just read the popphoto report just now, I own both Canon & Sigma DSLR's for varying reasons. I found the comparison (to the Nikon D80) somewhat unfair in the choice of lens used(the Nikon used a fixed 50 1.8, the Sigma an 18-50 2.8 zoom) just guessing that it was the reason for the contrast falling low towards the corners on the sigma files. In my own experience, majority of my clients prefer product shots done with the Sigma SD9/SD14 (over the Canon 20d/1ds-M1).



at 7/3/2008 5:16:55 PM, Mr Unbiased said:
I have no bias with respect to the SD14. I'm currently lining up to buy my first DSLR having owned only a compact since my Practika 35mm kit gave up the ghost several years ago. I have read just about every article there is online re. the SD14 (including this load of baloney) and what I see it an underrated innovative technology inside a less than perfect body. I've seen loads of direct image comparisons with cameras now costing two or three times more (since the SD14 has dropped through the floor, price wise). It seems to me that the SD14 represents the closest to a good film camera that a mid-price DSLR can currently achieve. Most of the gripes about the SD14 are actually non-issues in many respects for me since I've always liked my 'serious' cameras primitive (from my Zenit EM when I was 12 - no TTL metering :) ). That said, it's a toss up between the ease of use and convenience of an Olympus E510, robustness and simplicity of a Pentax K10d (or the Samsung clone) OR the DS14. Truth is, I couldn't even consider a DS14 at its original retail price, but I suppose I should be thanking all the hacks who have dismissed it out of hand (or perhaps brand bias) for forcing the price down to a level when I can give it a try and swap it out for a K10 if I don't like it. Instinct says I'll probably like it though - though the two features I wish it had are in-body stabilization and weatherproofing. Were it not for the lack of those features the game would already be over.



at 7/8/2008 8:09:14 PM, Geoff said:
Even later to the party but I just can''t resist pointing out a few things:

1) That the SD14 is not a 14 MP camera is hardly news. Of course it''s not.

2) This statement "So, in real-world shooting -- where it''s hard to find finely detailed red-and-blue subjects or scenes that have little green or b&w detail" is entirely subjective and is best disregarded, perhaps with the rest of the article. What is "Real world shooting", and for WHO? How much is "little" detail? If you shoot sports and I shoot orchids, our "Real world shooting" will be quite different.

3) What''s the point in rubbishing a technology that is attempting to improve on the current norm?

That''s my three cents.



at 9/24/2008 7:25:44 AM, Nam said:
The usual fanboys go against a neutral and unbiased reviewer.
My Guess:
Foveon/Sigma employees have a clausel in their contracts that forces them to read and post in forums.
It reads like some posts are written by marketing managers.



at 10/17/2008 5:12:07 AM, Sagara said:
It is obvious by detecting or capturing all three colours (RGB) hit at a particular photosite at the photosite itself is a better technique rather than calculate it based on nearby photosites.

It also important to not get confused by marketing propaganda. You can calculate the number of pixels and the number of photodiodes required to capture that number of pixels. Its elementary math.

In Foveon case, it requires three photodiodes per image pixles.

Pixels and photodiodes are two different things. The difference was not obvious until Foveon introduces their X3 chip. Because we did not have a different image capturing technology.

To see the difference of these two technologies, one should compare images of same pixel count. Not at same photodiode count. One do not need to know even the number of photodiodes required to make that image. That''''s up to the sensor. Different technologies require different number of photodiodes. If you have a good eye sight you can see the difference.

The native resolution of Foveon''''s X3-14MP (P stands here for photodiodes, not pixels) is 2640x1760 pixels.

By today''''s standard, Foveon''''s X3-14MP sensor is too old to compare with modern cameras.

The real question is what happened to Foveon? Why their resolution stopped at 2640x1760 pixels? Is there any news that Foveon is working on a new higher resolution sensor? or has the Foveon''''s technology hit the limit and cannot be scaled be beyond this?





at 10/30/2008 4:55:45 PM, Steaphany Waelder said:
I recently purchased a Sigma SD14 and I''m satisfied with it''s performance. The decision to buy a camera was not based on popularity, Sigma is not on top there.

I agree with the Popular Photography comments regarding Super High Resolution mode being interpolated. It''s actually obvious, start out with an imager possessing 2640x1760 photo sites and multiply it by 1.745. Those extra pixels in the output file have to come from some where.

But, I have no intention to ever use any of the JPEG settings.

What impressed me with the SD14 and the Foveon imager was it''s ability to record the primary colors simultaneously at each photo site. By contrast, I have never considered any Bayer imager with it''s computationally intensive interpolation to raise the output image pixel count to match the photo site count satisfactory for my personal photographic needs. Everyone reading this is familiar with the concept of actual measurements always surpass predictions or interpolations.

From someone who has researched the technology prior to purchase from both Sigma and Foveon, decided that the SD14 offered the features and quality desired, and has hands on use, it delivers.

I did my own side by side comparison with a 6 MP Bayer imager camera and the quality produced by the SD14 has it beat.

My take on the resolution issue is the SD14 is a 4.7 M photo site imager with a raw output image with 4.7 M pixels. That 10 M photo site Bayer imager should be reduced to one RGBG square defining one image pixel, i.e. 2.5 M Pixel. Just remember, that I''m not working in marketing trying to sell am item where the preponderance of people are under the illusion that more means better.



at 10/30/2008 10:22:50 PM, PATRICK said:
I do not care about the technical specifications. I do care about the image produced. I find that with the SD14 I get more "pop" out of my images with little or no time in image editing. It produces great prints as well. When I use my Canon 40d I also get great images but it requires much more effort in the editing room. The SD14 is great tool for producing great images. I was skeptical of the SD14 until I got one and began using it. It is my first choice for well lit non-sports photography. The big drawback is noise at the higher iso settings. Canon is king in the noise/low light arena. I have used Canon for the past 12 years and will say that the Sigma is much more fun to shoot with. I do not know why this is, maybe it is because it just acts differently than the big guns in the camera market. I guess that people should not rely on specs and numbers to make their decisions for them.



at 10/31/2008 5:54:01 AM, Steaphany Waelder said:
Patrick, Noise can easily be dealt with, just take a look at what post processing software tools that amateur and professional astronomers use. The technique, referred to as image stacking, aims to improve the signal to noise ratio as well as compensate for variations in gain between the imager''s photo sites and for variations in photo site bias and light level across the field of view. One of the packages that I use is RegiStax and unlike some astronomical stacking packages, RegiStax will work with regular, non-star field, photographs. The technique basically amounts to taking multiple photographs of the same scene, which limits applicability to relatively static scenes, aligning the images together, and computing an average. This improves both clarity and eliminates noise with out loosing any image detail, as the random noise is averaged out across the combined stack. If available, variations in photo site gain and hot photo sites are compensated by inclusion of Dark frames and photo site bias plus light variations across the imager are compensated by including Flat frames. Just run a Google on RegiStax and you''ll find it.



at 11/29/2008 11:13:50 AM, Alan Rockwood said:
I want to give a different twist to some comments already made by others and bring out a few other subtle points as well.

First, as has been noted by others, Foveon is not really a 14 megapixel sensor. From the point of view of signal processing theory it is only a 4.7 megapixel sensor.

Second, a 10 megapixel Bayer sensor is not really a 10 sensor. From the point of view of image processing it is a five megapixel green sensor, interleaved with a 2.5 megapixel blue sensor, and a 2.5 megapixel red sensor.

Now, let''s talk image processing theory. The Nyquist theorem provides a hard limit on the resolution that can be achieved by sampling an image. Interpolation cannot recover image details lost due to the Nyquist limit. Interpolation may fill in some numbers using a computational algorithm, but it cannot truly resolve missing detail, i.e. the resulting detail added by interpolation is at best an interesting fiction. This means that a 10 megapixel Bayer sensor can never resolve better 5 megapixels, and that is optimistic because it considers only the green channel, which is the highest resolution of the three channels.

Therefore, the "true" resolution of a 10 megapixel Bayer sensor will be less than 5 megapixels when applied to a color image. The resolution in this case is some kind of weighted average of the resolution of the 5 megapixel green channel and the two other color channels of 2.5 megapixel each. It is probably closer to 5 megapixels, given the fact that humans perceive sharpness mainly from the green portion of the spectrum. (This is why Bayer sensors are designed to use more green sensors than red or blue sensors.)

Let''s be optimistic then and rate a 10 megapixel Bayer sensor at true resolution of a little less than 5 megapixel, perhaps something in the 4.5 to 4.9 megapixel range. Well, what do you know then, this would predict that a 10 megapixel Bayer sensor should have a resolution very close to that of a 4.7 megapixel Foveon sensor, and this is not much different from what is found in practical product tests.

Bottom line: From the point of view of image processing theory and resolution, cut the pixel rating of a Bayer sensor in half (actually, cut it by slightly more than one half), and cut Foveon’s pixel rating to one third of its stated rating, and you will get a pretty good estimate of the true resolving potential for the two types of sensor.






at 1/14/2009 4:00:04 PM, mr klone said:
camera writing slow... but image quality one of the best. presently own for comparison sd14= canon 5d,canon sti,nikon d80.



at 4/9/2009 1:28:10 PM, craigi said:
At $350 currently, the SD14 is quite a deal BUT ONLY IF it fits the need.
In my case, it didn''t. It is for people who know what they are doing and are willing to do post processing on every photo. Still, that one out of ten photos that I took which were somewhat right - are definitely a step up in detail from any camera in that discounted price range. Especially stuff like the patterns on a high end rug, or the fur on an animal, etc.....

I think either Sigma or someone else will eventually get it right, but for now these products should be considered "beta" and for those who go in with their eyes open (know that they want - meaning generally well lit still photography.



at 4/9/2009 1:36:46 PM, Brian Dipert said:
Dear craigi, and as I just Tweeted (www.twitter.com/brianzbrain/statuses/1485283581), the Sigma DP1 is down to $399 today only at Amazon...



at 5/1/2009 6:29:36 PM, guardian said:
I appreciate the above remarks posted by Alan Rockwood. I studied the Nyquist sampling theory many years ago in grad school, in a course on information theory. It is interesting to find Nyquist theory predicting/confirming what most folks today acknowledge is the right Bayer equivalence for the Sigma SD14. The asinine Sigma marketing hype for the SD14, with the 14+ megapixel equivalence claim, is a shame. All it does is set a great camera up for (well justified) criticism.

I bought my new SD14 body very recently for $315 and I could NOT be more pleased. I guess thrilled would closer to how I feel about my purchase. That was the base cost only. I also had to pay for shipping ($15), for memory ($10), and for an adapter ($12) so I could use a lens I already owned. But still, that''''s not a lot for such a fantastic DSLR camera body.

I''''m an old film camera guy so all of the "problems" with the SD14 don''''t exist for me. In fact, highly automated cameras annoy me. But the photographs obtainable with this camera are exceptional. It''''s the closest thing to film out there today in a digital camera. What a great camera!!

The SD15 is coming out not too long from now. It has the same Foveon sensor as the SD14. I''''m sure it will have features I don''''t have. But it''''s going to be a while before anyone can purchase an SD15 for south of $350!

There''''s an excellent, though somewhat technical, article about the SD14. It is written by a guy who wrote Bayer interpolation algorithms. He talks about the "Bayer blur". To access a link to the article, Google this phrase: SD14 can it hang with the big dogs?

If you read the article, don''''t miss the remarkable photo of Jake. Jake is a very cool cat!



at 5/9/2009 2:25:25 AM, Tiamation said:
Big lens, hackable, cases exist where it is not hated; better to squeeze the technology hard to make those claims come in, as is done with digital film cameras, and then report on how blasted contrived those cases were to come by.

That or buy the Twitter card for the camera. It has that slot, right?



at 5/17/2009 5:55:02 AM, yadda said:
Tiamation: wait...what?





at 5/20/2009 1:31:15 AM, dupont said:
I despise the SD14's flash, the Sigma Pro Photo software, and the painfully long file writing.

I love the SD14's images (particularly when using some of my classic M42 lenses) and it's gimmick-free layout.

Canons, Nikons, and Pentaxes are far more low-maintenance cameras than the SD14, and probably better cameras for the vast majority of users.

But for image purists like me, be it a macro shot of a flower or a candid shot of my daughter (or a landscape shot of the mountains, or a still-life of my desk, or a sunrise shot on the Puget Sound), the SD14 gets my vote hands down. Pixel-schmixel. Let's compare pictures and then we'll talk.





at 5/20/2009 10:30:42 AM, bob said:
Kudos to Sigma for pioneering this technology. This article is completed irrelevant seeing how it is comparing a relatively new technology that is not mainstream vs. a mature one that is mainstream. With time and investment I feel the Foveon sensor has the potential to replace all Bayer sensors for high quality cameras. Wait and see, if not then you can post this article.







at 5/20/2009 10:56:23 AM, Brian Dipert said:
Dear bob, thanks for the chuckle. Foveon introduced its first X3 sensor more than seven years ago, and according to Gilder's book on Foveon 'The Silicon Eye', development began in 1997. Define 'relatively new technology'? Gimme a break...






at 6/18/2009 3:56:15 PM, joejoe said:
I think Alan Rockwood sums it up well.

Brian, I usually respect your opinions but in this case you lost track of your own facts, namely that "Bayer pattern sensors (are forced to) use low-pass filters" and how this degrades their claimed resolution.

For me, the important issue that doesn't get discussed is the problem of color cross contamination inherent in the Foveon sensor. There is no hard separation between the colors of light in a Foveon sensor. Assuming each color site is not infinitely thin, it will be sensing an averaged mix of colors. This causes the much longer processing times.

I believe this is related to the real problem Foveon has in the market: their sensor is simply too expensive to build and they have to take short cuts such as greatly reducing the number of imaging sites. Possibly there is variation in color cross contamination which becomes too difficult to compensate for as the pixel count grows.

The original promise of Foveon was to take multiple color samples per site. On a site for site comparison, it sounds great.

When this got too hard, they resorted to counting each site as 3 pixels. If they could have built a sensor with 10mega sites, each site 3 color, in a system with comparable processing times to a 10 megapixel bayer sensor, I don't think anyone would complain.

The fact that they did not do this means to me that they just can't get the yield high enough to sell the sensor at a price comparable to a bayer sensor.




at 6/18/2009 4:09:41 PM, Brian Dipert said:
Dear joejoe, I don't disagree with anything you've said. I'm scratching my head trying to figure out how you could have interpreted from my writeup that I had in any way, shape or form 'drank Foveon's Kool-Aid'



at 7/15/2009 2:42:16 PM, joejoe said:
Brian, sorry it didn't seem to come out the way I intended. My complaint was the opposite of saying that you 'drank Foveon's Kool-Aid'. From there, I went into some problems with Foveon that I don't think get enough emphasis.

But back to the issue of how "Bayer pattern sensors (are forced to) use low-pass filters" and how this degrades their claimed resolution. It is fair for you to say that Foveon doesn't give their claimed resolution. But neither does Bayer. All in all, I think the most accurate true Bayer resolution is 50% of their sensor sites. So a so-called 10 megapixel sensor is really 5 megapixel.

Put it another way, you acknowledge that Bayer requires low pass filters and we all know that means a loss of resolution.

Well, I see that I'm just repeating Alan Rockwood so I'll just say I agree with everything he said.




at 7/23/2009 8:40:56 AM, AFS said:
Well, I'm a professional photographer and I have used lots of cameras like the Fuji Finepix S5Pro , Nikon D100 and Canon EOS 5D, among many other ornes.

I can tell you all that the Foveon X3 sensor from the Sigma DP2 really rocks, delivering extremely crisp and detail rich images. You are all just talking too much. Try it and see by yourselves.

By the way I'm an engineer and I worked for a long long time with signal processing. Bayer type sensors have a big problem, called color interpolation. A pixel can have UP TO 1/3 of the color RGB value, maximum. The other 2/3 need to be estimated by interpolation. This will ALWAYS introduce color artifacts, detail loss and other nasty things.

You you are getting inferior pictures from a Foveon, you're doing something wrong, like comparing an EOS 5d-II with a pro S-series lens against a Sigma SD-14 with an amateur lens. Be serious ! Second thing: Foveons are to be used ONLY in raw mode. If you need a larger image interpolate to 2x using Lanczos 8x8.

C'mon, IMHO the author has a biased opinion and looks like trying to sell his fish.



at 7/23/2009 8:53:51 AM, Antonio said:
It's much easyer to upsample a 4.7 MP image to 2x larger rather than doing a really good color interpolation.

Supersamples images from a Foveon *may* have more detail than from conventional Bayer type sensors, in terms of pure mathemathics. It's just a matter of choosing a better algorithm than bilinear, bicubic and splines. I agree about the Lanczos, but you may also try the Mitchell algorithm.

You're all talking too much. Now show your pictures and tests, specifying the test conditins and equipment and maybe I'll consider something more than people just trying to say beautiful words here.

I have a Sigma SD-14 and a Sony A900. Believe me, the Sigma camera really rocks in terms of sharpness.

And like Mr. AFS stated, are you comparing lenses of the same class ? Not fair to compare a pro Nikkor against the SD-14 kit lens. LOL. Funny.

I don't believe in magazine reviews. I believe just in my eyes.




at 7/26/2009 3:30:25 PM, Fernando Soares said:
It's very interesting to see that some people are no so blind and trust in every crap some "experts" write all over the internet. The posts from joejoe, Antonio, AFS and guardian proves my point. Those guys knows what they are saying.

- Any kind of interpolation will insert artifacts NO MATTER of what kind of algorithm

- Spatial upsampling is far more easy to do rather than color interpolation. It will still introduce some artifacts but they will be much less annoying than color artifacts. I agree about the Lanczos 8x8.

- Bayer process CUTS information and adds "presumed" information.

I agree with the "fishy" opinion. Funny term.



at 7/29/2009 10:43:14 AM, Inquisitor said:
Mr Rockwood is pretty right. You commited a HUGE mistake and lost your path and any sense about the bayer vs foveon sensor. It's just about mathematics and physics, and I now know that your knowledge is pretty limited in this area. Sorry. Really.

The post from Mr. AFS put all this stuff in a somewhat harsh, but direct way. I must also agree with Mr. Soares statement.

Mr. Dipert, nice try, but you said a lot of biased (to the wrong diresction) information and surely you don't have any mathematical background in this area. Again, sorry for being so direct.

1) If you want to compare IMAGES, you need to do a test in controlled conditions, in real world. Yes, I know that you know how to use target charts... =)

2) You need to use equivalent lenses, if the same model doesn't exists for both cameras. Again, not smart (or maybe just too smart) to compare images from a sigma kit lens with a Pro Nikkor or something in this sense.

3) Light conditions MUST be the same, because the sensor signal/noise ratio may have a noticeable contribution.

4) And for God's sake... Please don't insist about that black and white s**t. Who the hell on earth shoots 100% BW in a digital camera ? And WHY,WHY,WHY someone would let the camera itself do the BW processing insteas of using a good dedicated software ? Gimme a break...


5) Shoot in REAL world, with performace compatible optics and compare REAL pictures. Best: Show them to us.






at 7/29/2009 5:15:00 PM, joejoe said:
Inquisitor reminded me of another reason I think you 'drank the anti-Foveon Kool-Aid' and that is the use of Black-and-white test target resolution as your very first comparison.

Most of the people commenting here will say "of course the bayer sensor performed a little better, that test is the one that favors them the most". But I suspect most users do not care very much about Black-and-white photographs.

In the comparisons that favor Foveon, you dismiss it by saying it's not very relevant but you uncritically accept the B&W results with no qualifications as to real world usefulness.




at 7/30/2009 5:40:49 PM, Inquisitor said:
Lol.. I loved the "drank the anti-Foveon Kool-Aid"... We should give him a break, otherwise his sponsors won't give him other cameras to play =)

That's exactly what I meant when I said he has a biased review... This review was made just to expose a very tendencious point of view. He's a theoretical photographer who shoots targets and garage doors for tests. Again, show us pictures from real world and real situations. After this we can talk.

Want some nice ones?

1) any kind of mesh (tissues , fishing nets)

2) forest scenes with leaves against sky, grass

3) bright cumulus clouds over a deep blue sky

4) flower/insect macros with fine veins

5) The best one: astrophotography ! take a wide field picture, with a 40mm lens in your BEST non Foveon SLR, attached to a tracking mount and repeat the test with a Foveon based camera. Set both to the same ISO setting and do exposures from 5s to 1 minute at f=2.8 ; You will be surprised when you see that the Bayer sensor picture shows LESS stars. Think Why as an excercice =) That's why astrophotographers uses monochromatic sensors with RGB filters over.

Well... better stop here.




at 7/30/2009 5:51:56 PM, Crappy arcticle said:
Man I almost had an hearth attack when I read the Author's replies.

at 7/16/2007 5:31:09 PM, Brian Dipert said:
Dear Christian, I'll requote from Popular Photography's writeup...

at 7/15/2007 3:06:03 PM, Brian Dipert said:
Dear Laurence Matson, peruse (for example) the Wikipedia definition of 'pixel'


Quoting Wikipedia ? ROFL !!!!

Popular Photography ? Wow, what a serious pubrication eh !

What's next ? A MS Windows arcticle based on MS papers ?










at 8/12/2009 10:42:23 AM, dupont said:
So, I went out yesterday to the Huntington library with my e510 and my sd14 for a completely non-scientific test of image quality. I set the cameras on "A" and gave them identical aperture values, then started shooting, mainly close-up shots of flowers, etc. They both had zooms. What did I find? Exactly what I expected. The Oly had truer color representation... sometimes the Sigma was off wildly. But the Sigma out-resolved the Oly by a mile. At 100% the Sigma was just in a different ballpark. The edges on the flowers were crisper, it resolved more detail, etc. I then asked my wife which of the two images she liked best in each case as I showed them on my G4 laptop, and 8 times out of 10, she preferred the Sigma shots. It seems to me--and has always seemed to me--that the Sigma far outperforms 10mp cameras. I understand all (well, most of) the science behind it and the conclusion that a Sigma should perform the same as a 10mp camera (that uses Bayer), but why in the real world does it "look and feel" like the Sigma actually performs on par with 12-14mp cameras? And this is something I've noticed in consistent usage over the period of a year... Anyone care to opine?



at 8/12/2009 10:45:41 AM, dupont said:
by "outperforms 10mp cameras," I mean that it outperforms in terms of image quality. As for the buggy software, slow response time, and sometimes laughably wrong color representation, many other cameras will outperform the SD14. No questions there. Which is why I have the SD14 for certain photographic assignments, and the e510 for others.



at 8/12/2009 10:57:37 PM, Inquisitor to Dupont said:
Yes, it will outperform most of 10 MP cameras. I have a bunch of digital cameras, including a Sigma DP2 that shares the same sensor of the SD14. Shooting in RAW at ISO 100 and using the bundled software to generate TIFF files and upsampling them to 12 MP (from 4.7) using the Lanczos algorithm ( I use PictureWindow ), I got astonishing results, pairing with my EOS 5D with the 17-40 L Series Zoom. Not cheap glass you see... And bleieve me , the EOS-5D is an excellent camera, simply the best on its class.

The DP2 outperforms by far my two Panasonics (LX3 and TZ4). Again, the LX3 is not a cheap camera.

In good hands, those Foveon beasts will give a run on much more expensive cameras, and that's what is making some people mad...

take a look at: www.rytterfalk.com





at 9/12/2009 3:48:13 PM, FoveonFanBoy said:
First let me say, thanks to all of you for your input on this blog. I just discovered it and really enjoyed all the banter. I orginate in film and have been a Canon Fanboy for a long time. I have most of the prosumer digtal cameras, Rebels,20d,30d,40d..etc. In this price range I found clipped highlights and cartoon skys. Sure some things looked pretty damn good. But something was always to un-film like, to flat, unreal if you will. I switched back and forth from film to digital over the last 8 years giving digital repeat chances to develop the analog look. I went through the same thing with music cd's. I had almost given up on digital until recently when I took a good long look at Foveon images. I had dismissed the Sigmas due to low pixel count. I am simply blown away by the film-like quality the foveon sensor capture. I am praying that Foveon suvives the inane attempts at camera manufacture that Sigma is fumbling through. I have been re-energized to take pictures again. Well, my two cents is this, both sensor camps fudge their pixel descriptions to gain sales. Its a fact. But if you can't see the difference in the output images from the Foveon then I feel sorry for you. I don't mean this as an insult to anyone. I really mean it, you can't be taught this skill. I feel sorry for the blind and the deaf. I would be crushed it I couldn't see the diffence in image quality. I wouldn't know what to aspire to.... The image quality of the Foveon sensors is amazing. I only hope their will be better sensors in better cameras before Foveon loses out to an inferior image capture technology.
M



at 9/16/2009 5:08:30 PM, Inquisitor said:
As I said... Some people just "pretends" to be experts, like the author.

The output from a Foveon sensor ha much more detail than bayer sensors. Juts look at the pictures.



at 9/16/2009 5:32:42 PM, spinshot said:
Ford v. Chevy v. Dodge (got Hemi?) My camera can pee farther than urs (in a headwind).

Thought digital would take much longer to rival film than it did. Fuji Velvia 50 was my favorite film for its super saturation and contrast. Couldn't afford to make pictures as a hobby so I put the cameras away and balked at the $5k digital cameras that made flat looking pictures and were worth 1/2 as much 6 months later. How much for that Kodak DCS today? Got change for a $50? Trade you straight across for my vintage Pentax K1000, the meter still works, even. TTL, yeah!

Decided one day that DSLRs were cheap enough to not cry about and started looking at offerings from Chevy and Ford, uh I mean Nikon and Canon. Years of 35mm taught me you can't go wrong with either brand. Had heard of the foveon sensor years and years back and somehow stumbled across some pictures made by Sigma's(?!) SD14. "Isn't that the cheapie lens mfr?" I'm a glass snob. Thanks, Dad. Nikkor, Canon or Schneider FTW.

My reaction to those pictures was something along the lines of "WTF?!" Not many days thereafter followed by the UPS guy dropping off my Sigma after some ebay bargain hunting. Hey, cool! They gave me a camera bag an extra battery too!

Am I a Sigma fan? The camera is buggy, tempermental and slow. The JPEGS are all the wrong color so I have to shoot RAW and process one by one. But hey still faster than the 1 hour fotomat and way faster and cleaner than the bathroom developer, stopper and fixer setup.

But the images...

POP.

At the end of the day, it's what makes your client or beholder of your work say "wow!"

Canon make a camera that makes pictures pop like this and I will buy it, Nikon make a camera that makes pictures pop like this and I will buy it. Heck Chevy, make a camera that makes pictures pop like this and I will drive it.

-fin.



at 9/21/2009 2:49:21 PM, AFS said:
Well, If someone still have any doubt about Foveon's capability, just take a look at the FOVEON GROUP at FLICKR. An after this I would like to tell the author just to swallow gently and stop saying bullshit.





at 9/21/2009 3:20:50 PM, Xin-Huan said:
Quoting:

Sigma SD14 Dissatisfaction: Finally Believe Me, Foveon Fanboys?

------

I beg your pardon ! It seems that you dont know anything about cameras, photography and digital imaging devices. Your arguments are inconsistent. At least study before posting what you wrote. Is someone paying you to say such kind of s**t ?

If you got inferior results from a Foveon, you're a pretty BAD photographer or did it intentionally.

For the ones who didn't got the picture yet:

Don't believe in reviews, try for yourself instead. The author used WRONG methodology for the test and clearly doesn't knows anything about the subject.

BTW, I'm a PROFESSIONAL photographer and I have an EOS-5D Mk2 with some really good L series objectives, and a Sigma SD14. 5D is more sturdy, can tolerate good wacks, has the best lenses ever, but the SD14 pictures are SUPERB.









at 10/1/2009 10:33:50 PM, Simon said:
Hahahahaha... This guys is being nailed since 2007 !
Surely he deserves !



at 10/6/2009 12:58:11 AM, just me said:
There's a number of misunderstandings about Foveon in the comments. First of all, Foveon does not record primary colors on each layer. Read the patents, people. What it records must be converted to RGB and this is a messy mathematical transform that's a lot more complex than Bayer is. That's also partly why it doesn't handle high ISO that well (the transform itself adds noise).


Ever wonder why Sigma's own software is so slow? Or why the first two Sigma cameras never did JPEG in camera? There's a lot of computation going on. Bayer is comparatively easy to process and far more accurate than the fanbois want to believe. It's also hard to get exactly correct which is why every Sigma camera has a slightly different 'look'.


As for images that pop, keep in mind that the Sigma software boosts contrast and sharpening even when set to zero. Other cameras generally don't do that, so the Sigma images are going to 'pop' but it has absolutely nothing to do with the sensor and everything to do with the processing. Crank up the contrast and sharpness on a Bayer camera and it too will pop.


Alan Rockwood - a 10 MP bayer sensor is a 10 MP sensor. It doesn't matter that it has 2.5 MP of red and blue and 5 MP of green. The demosaic process (of which there are many many variants) uses every pixel. In short, 10 million input, 10 million output.


Nor is Nyquist measured in megapixels, but cycles per pixel or lines per picture height/width. A 10 MP Bayer sensor does not have '5 MP of resolution' (a meaningless statement). What Nyquist measures is the ability to resolve lines of detail, and in the case of a 10 MP sensor (3872 x 2592 for a Nikon D80), an absolute maximum of 3872 lines per picture width or 2592 lines per picture height. It can never be higher. The fact that some pixels are red or green is irrelevant. Seriously, go read a couple of papers on Bayer algorithms. Claiming that a camera that has 2640 x 1760 pixels can outresolve one which has 3872 x 2592 is hilarious.


In the real world (not the fantasy land of some of these commenters), any system will resolve about 70-80% of Nyquist before aliasing becomes a big problem, no matter what the sensor type is, or whether it's audio or video. Sigma can get away without an anti-alias filter because the artifacts aren't as ugly as on Bayer. Unfortunately, aliasing is false detail, not real detail. Those amazing details in Foveon images are mainly alias artifacts and not in the original subject. Basic signal theory here. That's why on a resolution chart, you get the 9 versus 5 lines - classic aliasing.


Fernando Soares - since the Sigma image has fewer pixels than other cameras, it must be interpolated more to obtain the same size final result, be it a print or on screen. Therefore, by your own analysis, you don't want Foveon. Also, spatial upsampling is not easier than color interpolation, nor is it less noticeable - it's actually much more noticeable. Your eye can't resolve color as well as it does luminance. That's why Bayer works so well, it's based on how human eyes work.


Inquisitor & joejoe - why black and white charts? Ask your eye doctor why his charts are b/w. The only time an eye doctor uses color charts is for color blindness, not testing how well you can see detail. There's a really good reason for that, and it's because humans don't see color that well. Check any book on human vision.


And I love statements like 'a Foveon sensor has much more detail than Bayer sensors.' Really? All Bayer sensors?? Every single one? More detail than on a 60 megapixel Hasselblad? More detail than a 24 megapixel Nikon D3x? Get real.





at 10/7/2009 6:44:39 PM, Xin-Huan said:
Strange, I posted a comment here and I can't see it. Just after "Just Me"



at 10/7/2009 6:54:14 PM, Xin-Huan said:
"And I love statements like 'a Foveon sensor has much more detail than Bayer sensors.' Really? All Bayer sensors?? Every single one? More detail than on a 60 megapixel Hasselblad? More detail than a 24 megapixel Nikon D3x? Get real. "

Well, I think that you are trying to be a smartass here, sorry. Those guys surely meant about a Foven vs. 10-12 MP Bayer sensors.


" Also, spatial upsampling is not easier than color interpolation, nor is it less noticeable - it's actually much more noticeable"


Not true. I work with signal processing for the last 10 years and also a D.Sc. in this discipline. Not a matter of being easier, but what they meant was:

"upsampling with the right algorithm, Lanczos for example, can lend to a much more realistic image, due the simple fact of all the needed information is already in the original image. Downsampling is much more complicated, and a decent color interpolation if even more difficult"

Have you EVER tried to make any implementation of the mentioned algorithms ?






at 10/7/2009 7:17:30 PM, Xin-Huan said:
Just adding:

"Claiming that a camera that has 2640 x 1760 pixels can outresolve one which has 3872 x 2592 is hilarious"

Also not true. It WILL depend on some very well known factors, like the lens quality and sensor size. Do you believe that an 8MP Sony cellphone can produce better images than my old Olympus C5050 5MP camera ? Not even in your dreams. Yes. It CAN outresolve in some circunstances.





at 10/8/2009 8:47:40 AM, Bob said:
About "Just Me" post:

I don't agree about what you said concerning Mr. Fernando Soares post.

He said:

"- Any kind of interpolation will insert artifacts NO MATTER of what kind of algorithm

- Spatial upsampling is far more easy to do rather than color interpolation. It will still introduce some artifacts but they will be much less annoying than color artifacts. I agree about the Lanczos 8x8.

- Bayer process CUTS information and adds "presumed" information. "


You replied:

"Fernando Soares - since the Sigma image has fewer pixels than other cameras, it must be interpolated more to obtain the same size final result, be it a print or on screen. Therefore, by your own analysis, you don't want Foveon. Also, spatial upsampling is not easier than color interpolation, nor is it less noticeable - it's actually much more noticeable. Your eye can't resolve color as well as it does luminance. That's why Bayer works so well, it's based on how human eyes work. "


Mr. Soares said a completely different thing ! "By your own analysis, you don't want Foveon" you said ?

Mr. Soares statements are 100% accurate, sorry.

For me, you , like the author, have a highly biased opinion and never tried a Foveon based camera. And if you did, you must be a pretty bad photographer.

Enough about his thread...


Want definition ? Use FILM and a drum scanner. Want a tip ? Kodak Lumiere in 6x9 INCHES size. Maybe in the next 20 years we will see a digicam capable to face this.





at 10/8/2009 6:06:12 PM, just me said:
Xin-Huan -
"upsampling with the right algorithm, Lanczos for example, can lend to a much more realistic image, due the simple fact of all the needed information is already in the original image. Downsampling is much more complicated, and a decent color interpolation if even more difficult"

Upsampling can't add information that isn't there. An upsampled image can never be as good as an image that starts off with higher resolution and that doesn't need to be upsampled. Color interpolation doesn't matter that much because the human eye doesn't resolve color as well as luminance. You don't need fancy algorithms, so it's much easier.


"Well, I think that you are trying to be a smartass here, sorry. Those guys surely meant about a Foven vs. 10-12 MP Bayer sensors."

That's not what was written. I've seen plenty of people claim that Foveon will always be better than any Bayer camera ever made because of the way it works and that looked like yet another such claim.


"It WILL depend on some very well known factors, like the lens quality and sensor size. Do you believe that an 8MP Sony cellphone can produce better images than my old Olympus C5050 5MP camera ? Not even in your dreams. Yes. It CAN outresolve in some circunstances."

If you use a lower quality lens or a smaller sensor, the difference will be due to the lens or sensor size, not the sensor type. Did you have a point here?


Bob-
"For me, you , like the author, have a highly biased opinion and never tried a Foveon based camera. And if you did, you must be a pretty bad photographer."

Resorting to personal attacks means you don't have any argument.


"Want definition ? Use FILM and a drum scanner. Want a tip ? Kodak Lumiere in 6x9 INCHES size. Maybe in the next 20 years we will see a digicam capable to face this. "

We've had cameras that can surpass film cameras for years. Try a Better Light scanning back on that large format camera of yours, and being a scanning back, there is no Bayer interpolation either. The Canon 1Ds III or Nikon D3x produce better results than any 35mm film camera and comparable to medium format film cameras. Even a lowly 40D or D90 outperforms 35mm film cameras.





at 10/9/2009 7:25:37 AM, Xin Huan said:
Juste me,

I think you have a problem in understanding what people are trying to say.

"Upsampling can't add information that isn't there. An upsampled image can never be as good as an image that starts off with higher resolution and that doesn't need to be upsampled. Color interpolation doesn't matter that much because the human eye doesn't resolve color as well as luminance. You don't need fancy algorithms, so it's much easier. "


The point is not to add information that wasn't there. This is exactly what the bayer algorithms does. Like someone else said earlier, try to do an astrophoto with a bayer sensor and see by yourself. Star colors will be changed, blur, missing stars and all sort of problems will appear. Even with a 500MP sensor.





at 10/9/2009 2:59:02 PM, just me said:
"try to do an astrophoto with a bayer sensor and see by yourself. Star colors will be changed, blur, missing stars and all sort of problems will appear. Even with a 500MP sensor."

Where do people come up with this crazy stuff?

Star colors will be changed? From what color to what color? Missing stars? What other problems? Got an actual example? Didn't think so.

And where is this mythical 500 megapixel sensor? Who makes it? It doesn't exist, does it?

But let's assume it does. Are you actually saying that a 4.7 megapixel Foveon sensor is going to do better than a sensor with more than 100 times as many pixels??? Do you realize how absurd that is?



at 10/11/2009 5:26:52 PM, GEORGE GREENWOOD said:
Hello, guys.

Just to clear some misundertanding...

at 10/9/2009 2:59:02 PM, just me said:

"try to do an astrophoto with a bayer sensor and see by yourself. Star colors will be changed, blur, missing stars and all sort of problems will appear. Even with a 500MP sensor."

Star colors will be changed? From what color to what color? Missing stars? What other problems? Got an actual example? Didn't think so.

YES, COLOR WILL CHANGE AND SEVERAL STARS SIMPLY WON'T SHOW. I WORK WITH ASTROPHOTOGRAPHY FOR 30+ YEARS AND BAYER TYPE CCDS AREN'T GOOD FOR THIS KIND OF APPLICATION. NOT EVEN AN EOS 5D MK-II.

1) STARS USUALLY PRODUCE PINPOINT IMAGES WHEN PROPERLY FOCUSED, SPECIALLY WITH WIDE FIELD SUBJECTS. STARS HAVE VERY DISTINCT SPECTRAL EMISSIONS, RED ONES DOESN'T EMMITS ANY SIGNIFICANT AMMOUNT OF BLUE LIGHT AND VICE VERSA.

2) IF A WELL FOCUSED RED STAR IS FOCUSED JUST OVER, FOR EXAMPLE, A BLUE PIXEL, IT SIMPLY WON'T BE REGISTERED. THIS IS A WELL KNOWN FACT. THE SAME WILL OCCURS WITH A BLUE STAR FOCUSED OVER A RED PIXEL

3) IN SOME CAMERAS, YELLOW AND ORANGE STARS MAY CHANGE COLOR. YELLOW ONES MAY SHIFT TO GREEN AND ORENGE ONES, TO RED.

4) PROFESSIONAL ASTRONOMICAL CAMERAS ALWAYS USES B&W SENSORS AND A SET OF OPTICAL FILTERS. THE CLASSIC R,G,B SET AND SOME OTHER SPEC. ONES LIKE H1,H2,MINUS ALPHA, SULPHUR BAND, OH BAND, OXYGEN-I,II AND MUCH MORE. THOSE CAMERAS ARE USUALLY FITTED WITH SOME SORT OF CRYOGENIC DEVICE FOR NOISE REDUCTION. NO BAYER SENSOR CAN BE USED IN ASTROPHOTO, AT LEAST NOT FOR PROFESSIONAL USE OR WITHOUT SOME VERY ADVANCED SIGNAL PROCESSING WORK OVER THE IMAGES.



YOU "DON'T THINK SO" JUST BECAUSE YOU SIMPLY ARE NOT QUALIFIED TO COMMENT ABOUT THIS MATTER. YOU JUST TALK TOO MUCH. OF COURSE WHEN THE CHINESE GUY SAID ABOUT A 500 MP SENSOR HE WAS MOCKING YOU, OR AT LEAST BEING SARCASTIC. GOT THE IDEA NOW ?

HELLO THERE, WAKE UP !

STOP SAYING THIS KIND OF BULLSHIT PLEASE.










at 10/11/2009 6:09:07 PM, Simon said:
Lol !

Still this thread ?

C'mon, there will be always people that will like Foveon cameras and people with the oppostite opinion.

Personally I prefer the images from my Sigma SD-14 rather than any other camera I've ever tried. The images are much more pleasant and with much better gradients, in MY opinion. I don't care about anyone's opinion about this subject. I like it and that's what matters to me.

I respect Mr. Huan's point of view. All he said makes sense. I'm not a scientist. I'm a photographer and I started in 1972. My current cameras are a Leica M8, a Blad with the CFV-39 back (not the CF-39) and an SD-15 just for fun. The M8 is not cheap stuff. Leitz lenses are the maybe best. The same comment about the CFV-39. Not the most expensive but not exactly cheap stuff.

The 39 MP images from the CFV-39 are awesome but, sorry, film detail is much better, specially with a low grain film like the Fuji Velvia 50 , Provia 100F or the venerable Panatomic-X from Kodak, developed in Rodinal. Just take a GOOD 20X APO magnifier and check.

The same Blad and Zeiss 100/3.5 Planar objetive. Film scores FARRRRRR better than the CFV-30.

Someone here stated that a 40D or a D90 outperforms 35mm film cameras. This guy must be kidding ! If a CFV-39 can't surpass old films like the ones I mentioned.... Well, better stop here, I won't waste my energy with things I already know and tested.

And for the Foveon owners: Yes, your SD-14, DP1 and DP2 can outperform many cameras fitted with bigger CCDs. Instead of all this waste of time, just check your results and see by yourselves.

- Canon owners will always say that Nikons are crap

- Nikon owners will always say that Canon sucks

- Leica owners will always say all the other are crap and sucks

LET'S LOCK THIS THREAD. IT'S DEAD AND NO MORE USEFUL.








at 10/12/2009 12:25:06 PM, just me said:
George - Fix your caps lock before spouting about sensors and show some respect for Brian and his blog as well as people you disagree with. We're all guests here and there is absolutely no need for profanity.


YES, COLOR WILL CHANGE AND SEVERAL STARS SIMPLY WON'T SHOW. I WORK WITH ASTROPHOTOGRAPHY FOR 30+ YEARS AND BAYER TYPE CCDS AREN'T GOOD FOR THIS KIND OF APPLICATION.

Really?

In the Sigma forum on DPReview, someone posted a star trail taken with a Sigma DP2. Since I can't link to it on this blog, look for a thread titled DP-Two, posted by FoveonFanboy on October 11, 2009. Use forum 1027 and message number 33313569 in the URL (pick any forum post there for the base format) to go directly to it.

The dots are due to multiple time exposures and the colors of the stars CHANGE, and that's with a Foveon sensor, not a Bayer sensor! Also notice that the stars have corners (aliasing) rather than being correctly captured as round.

Hard evidence that Foveon is not good for this kind of application at all.



Simon-

"Personally I prefer the images from my Sigma SD-14 rather than any other camera I've ever tried. The images are much more pleasant and with much better gradients, in MY opinion. I don't care about anyone's opinion about this subject. I like it and that's what matters to me."

If you like the results, that's great. It's the bogus claims that bug me. It's also very obvious that you don't care about anyone elses opinion, or facts for that matter.


"I respect Mr. Huan's point of view. All he said makes sense. I'm not a scientist."

If you were a scientist you'd realize that what he said does not make any sense at all.


"My current cameras are a Leica M8, a Blad with the CFV-39 back (not the CF-39) and an SD-15 just for fun."

Foveon users have the ability to travel through time now? Although the SD-15 was announced over a year ago, it has not been released yet.


"The 39 MP images from the CFV-39 are awesome but, sorry, film detail is much better, specially with a low grain film like the Fuji Velvia 50 , Provia 100F or the venerable Panatomic-X from Kodak, developed in Rodinal. Just take a GOOD 20X APO magnifier and check."

I have checked, and digital is better.


"Someone here stated that a 40D or a D90 outperforms 35mm film cameras. This guy must be kidding ! If a CFV-39 can't surpass old films like the ones I mentioned.... Well, better stop here, I won't waste my energy with things I already know and tested."

You're doing something wrong. Digital has outperformed film for many years, particularly in noise, dynamic range, high ISO and color accuracy. Which film can shoot at ISO 1600-3200 without any grain, or needing push processing to even get that speed?


"And for the Foveon owners: Yes, your SD-14, DP1 and DP2 can outperform many cameras fitted with bigger CCDs. Instead of all this waste of time, just check your results and see by yourselves."

It can't, and checking the results will confirm it.

You don't really believe that a 4.7 megapixel camera with a 1.7x sensor can outperform a 21 megapixel full frame sensor or a 39 megapixel medium format back, do you?




at 10/12/2009 5:46:10 PM, Simon said:
Just ME:

"My current cameras are a Leica M8, a Blad with the CFV-39 back (not the CF-39) and an SD-15 just for fun."

Foveon users have the ability to travel through time now? Although the SD-15 was announced over a year ago, it has not been released yet.



Clearly mistyped if you remember what i've post in the beginning. You're a jerk, with capital letters.




"The 39 MP images from the CFV-39 are awesome but, sorry, film detail is much better, specially with a low grain film like the Fuji Velvia 50 , Provia 100F or the venerable Panatomic-X from Kodak, developed in Rodinal. Just take a GOOD 20X APO magnifier and check."

I have checked, and digital is better.



No, You didn't. If you say this you're a liar.



"You're doing something wrong. Digital has outperformed film for many years, particularly in noise, dynamic range, high ISO and color accuracy. Which film can shoot at ISO 1600-3200 without any grain, or needing push processing to even get that speed? "

I have the impression that you're smoking pretty good stuff.


"You don't really believe that a 4.7 megapixel camera with a 1.7x sensor can outperform a 21 megapixel full frame sensor or a 39 megapixel medium format back, do you?"

Wow. You still didn't get the point. Maybe the drugs did some neural damage on you. NOT TO OUTPERFORM, I JUST SAID THAT PICTURES ARE MORE PLEASANT.

"You're doing something wrong. Digital has outperformed film for many years, particularly in noise, dynamic range, high ISO and color accuracy. Which film can shoot at ISO 1600-3200 without any grain, or needing push processing to even get that speed?"

Maybe LSD now... I said Panatomic-X, Velvia, Provia, All low grain films. Stop using acid please.


I also have the impression that you also will say that the Astronomer is also wrong. Maybe YOU work at NASA and of course knows everything better than this guy.

Man, You're a Psyco. Or justa Jerk.




at 10/12/2009 6:26:14 PM, Jason Clark said:
Wow, what's next?

DPreview isn't exactly inpartial. To quote DPreview is something like to quote Wikipedia !





at 10/13/2009 7:57:22 AM, Roger Weinfield said:
Interesting at least !

This "Just Me" guy clearly didn't read carefully what other people wrote here. He repeats things over and over again !

Simon said (hehe) about very low ISO and extremely low grain films. How could you even mention about push processing this kind of film to ISO 3200 ? Simon stated a completely different thing, all regarding SLOW speed films against digital cameras. And I agree with him. No camera on earth can surpass a Panatomic-X or Velvia 50. Sorry, you're really wrong. Maybe you really didn't made this test, or just don't realize how ridiculous your statements are ! Not funny, actually very sad to see people acting like you. Pay attention on what people said.

The guy never said that a 4.7 MP sensor would outperform a 21 or 30 MP sensor !

I wouldn't call you a je*k not that your are on drugs. I would call you a jack*ss instead. And maybe you have some cognitive deficiency, or just an extremely huge ego.

Also, from Mr. Jason Clark, I must agree with him. DPreview isn't inpartial. They say a lot of sh*t. There are a lot of makers sponsoring those kind of websites and it's a well known fact.

My best wishes,

Roger



at 10/13/2009 11:00:03 AM, Roger Weinfield said:
I just took a look at the post you mentioned about the DP2 deficiency in astrophoto.

From the post:

"Has anyone got messed with the DP2 for astronomy (stars)? I don't know, I wanted the streaks but the camera was set to 15 seconds with 30 second intervals. I'll mess with it again later hopefully."

You said

"The dots are due to multiple time exposures and the colors of the stars CHANGE, and that's with a Foveon sensor, not a Bayer sensor! Also notice that the stars have corners (aliasing) rather than being correctly captured as round."

Yes, multiple exposures, using the time lapse feature. The guy did a mistake, not the camera. And the aliasing you mentioned was obviously caused by vibration and a bad resizing algorithm. The color change was probably caused by a combination of flare and difraction. The brightest star on the left was also distorted because of lens edge distortion and it's more evident just for the fact it's much brighter than the other ones. Ordinary optics aren't for astro.

The astro guy up there surely meant about foveon technology and wasn't specific about using a DP2. The only bad thing about Foveons and astrophoto is simply the fact (well known) that Foveon's likes a lot of light. If someone wants to use it in astrophoto, the camera must be attached to a BIG aperture telescope, with a very precise tracking.



at 10/14/2009 11:30:39 AM, just me said:
Panatomic X is just one film out of dozens. Claiming that film is better than digital because one film MIGHT be better in one particular circumstance is silly. Not to mention that shooting slow films limits what you can shoot. That's why the vast majority of people shot ISO 100-400 films, not slow film. Even Kodachrome went from ISO 25 to 64 to 200.

Many people have done objective comparisons between film and digital, including Roger Clark, Norman Koren and Michael Reichmann, and they've found that modern digital cameras are better than just about every film, with numbers to back up their claims. I'd link to their tests, but that's prohibited here. Roger Clark's numbers show that a fine grain film such as Tech Pan, Velvia 50 or even Kodachrome 64 can be surpassed with a 16 megapixel Canon 1Ds Mark II, a camera that itself has been surpassed with later models.

The only evidence posted so far that film is better is essentially "I did some tests, and if you think otherwise, you're a liar and on drugs." Guess which one has more credibility.

Film also has other drawbacks, such as needing to be kept cool (including during a photo shoot on a hot day), carrying many rolls of film versus a couple of flash cards that slip into a pocket, being impossible to make a backup copy of film, dealing with film fading over time and dealing with airport X-rays for those who travel. Digital does not have those problems.

As for the dotted star trail photo, he didn't make a mistake, he wanted the dot effect. Vibration would cause blurry stars, not rectangular stars with corners. Flare would not cause a color change, nor would diffraction, and all of those would affect the entire image, not just in one area. The reality is that in the couple of minutes it took to make that photo, stars were reproduced with different colors, something that George and Xin Huan said would not happen on Foveon.

Many people say DPReview gets paid to say things about various brands, except that they say good and bad things about EVERY brand. That can only mean that everyone is paying them off, which is absurd. Amazon (who owns DPReview) is a publicly traded company and it would be extremely difficult to hide something like this. But since it's a "well known fact" that DPReview is sponsored by the camera companies, providing proof should be easy. Let's see the evidence.

Sigma, on the other hand, has paid shills, some of whom have posted to this thread. Online they pretend to be just another satisfied Foveon user and deny all ties with Sigma or Foveon, but if you go to PMA or Photokina trade shows, you can see them working IN the Sigma booth, giving demos and wearing the Sigma booth attire. They're anything but just another happy user. Thankfully, the FTC is starting to crack down on this, requiring people to have full disclosure or be fined.




at 10/14/2009 12:15:06 PM, Richard Goldman said:
Hi there,

Strange comments all over here, but I agree with some posts. I'll expose here what I think about.

- Film has drawbacks, surely. But digital also have.

- Not just Sigma get favours from people at PMA or Photokina. Every single camera maker does. All them do the same and it's part of the game.

- If you read carefully the reviews from DPreview, you'll see many interesting facts. Why they almost never complain seriously about a Nikon or Sony ? If you read carefully the pros and cons for each review and cross link them, they ommits some facts in some brands and overexpose some minimal problems for other brands. I think they're biased.

- "Roger Clark, Norman Koren and Michael Reichmann, and they've found that modern digital cameras are better than just about every film". Well, maybe them found it. I'm still not convinced, specially when I shoot a low grain film and scan it in a drum scanner. Actually, the images from a low iso film and drum scanner are far superior than any digital camera I've ever tested, and this includes The EOS-5D MK2, Nikon F100 and so. Justme, if you said that using a top digital camera is more practical than what I do, I would agree. But not in terms of quality.

- About Foveons, I have a Sigma DP2 and the images have the WOW factor. They aren't the best one ver of course but they impress a lot. The images shot in raw mode have a lot of punch, sometimes much more than the ones from my 5d MK2, even considering the far superior resolution from the 5D.

- I also played a little with an SD14 and my Meade LX200-ACF 16" telescope. For brighter subjects, like the M42 (Orion Nebula) the sd14 did a better job than my 5D. But for dimmer objects the 5D was better. For very dim, both are crap. In this case, you need a specialized monochrome camera and a filter set, do dozens of images then stack all and do a lot of image processing. The Foveon sensor produces far superior images from star clusters, like Omega Centauri. Moon images are also very detailed.


I wish you all fun. I found this blog when I was searching about astrophotography and Foveons.

I have no intention to come back here, as I meant, I just passed thru.






at 10/14/2009 3:03:02 PM, Juan Aznar, Spain said:
Greetings!

Not a Foveon user but to claim that digital is superior than film is a half truth. It will depends on a vast number of issues, like: smooth gradients, low light, light excess, and much more.

Very low ISO films still surpasses digital and this is not "silly". Silly is to put all in general.

Film has some inconvenience like mr. Justme said, but those are much less troublesome than digital. Last year I went to South America and my photo gear was a Nikon D100 as my primary camera, one D90 as my spare and an old FM2 just for fun. Well, After 7 days in the rainforest, both digital just stoped to work because of the not so friendly environment. Thanks god I still had my old FM2 and 30 film rolls. Temperatures were about 35-42 Celsius and RH "just" 95%.

The oposite situation happened in February 2009 when I was in Canada. Again, my digitals stopped. The funny thing was that my spare film camera was a Nikon N8008, also a very electronic camera but it resisted quite well to -40C. The digital ones just died.

Film is still one zillion times more reliable.

But even being a Nikon fan, I would like to try the DP1 and DP2 seriously. I have a friend in Cataluña who owns both cameras and for what I saw, the pictures have a very nice and emphatic look. Some of them really looks astonishing.


Forgive about my English, It's not my primary language.



at 10/15/2009 7:31:04 PM, FovoenFanboy said:
I gotta say, this thread got lively again. Couple of things, one read the November 09 shutterbug review. Last 3 paragraphs. I know it won't matter to some, but is a nice little story about the DP2 mixing with the likes of Nikon D3, DX3 and 5dMkii. Cool comparison, but anecdotal. Why does there have to be a war about Foveon anyways. It is infant technology trying to gain a foothold. Its true, that straight out of the DP2 output is rather sharp. Dymamic range is very good and the pictures pop. Really, I mean really they pop. The 5dmkii can have almost this kind of look, but at a much higher price. I have been shooting the DP2 for awhile now. Gawd, I love the images from this camera. It is amazing how defensive individuals are over sensors. I would gladly shoot the 5dMkii, it creates some incredible images. So, does the Foveon sensored cameras. I just like the photo realism that comes from the Foveons. Color separation, dynamic range and 3deeish output is not a myth. Shoot the damn sensor and see for yourself.

MJ



at 10/16/2009 11:25:48 AM, just me said:
"Its true, that straight out of the DP2 output is rather sharp. Dymamic range is very good and the pictures pop. Really, I mean really they pop."

Sigma Photo Pro gives a contrast boost and sharpens images, even when set to zero. Do the same in Nikon/Canon software or Photoshop and you can get a lot of 'pop' too.

"The 5dmkii can have almost this kind of look, but at a much higher price."

Any camera can and often at a lower price, without any lockups or other problems. There's even a dpreview thread going on right now about opening up the SD14 and soldering wires inside it to fix the lockups!

"I have been shooting the DP2 for awhile now. Gawd, I love the images from this camera."

Liking the results is all that matters. That doesn't mean the sensor is some gift from the heavens.

"Color separation, dynamic range and 3deeish output is not a myth. Shoot the damn sensor and see for yourself."

It is a myth. Delta-E (color errors) on the Foveon sensor is measurably worse than on Bayer (about 2-3 times as high) and it also suffers from metamerism. Dynamic range is also worse, measured at about 10 stops, compared to 12+ for the likes of a Canon 5D II or Nikon D700. The '3D effect' can happen with any camera, digital or film, and even with paintings. And I have shot with Foveon, thanks for asking.



at 10/17/2009 8:49:50 PM, Patrick Bellard said:
Hahaha !

This Mr. Just Me did everything, no matter on what kind of subject ! It's strange, coz 99% of people here have the clear opinion and preference for the Foveon based cameras. Maybe just him is right and all the other people here are stupid. Talking seriously now: get real, stats are well against you. Maybe you're a friend of Mr. Dipert , trying to save his reputation =)
Just kidding, no offense.


I had some good laughs when he said that just Sigma gave gifts to the public at PMA and Photokina. I got T-Shirts and hats form Canon, Leica, Nikon, Sony... !!!





at 10/21/2009 10:49:45 AM, Red said:
I took one whole day just to read all the posts... Lol !

Was the author paid to say such ammount of biased information ? I have a SD14 and a Nikon D90 and the SD14 pictures are far better looking ! I'll receive my "new" D100 in a few days.

I'm not exactly a young guy... I started in mid '60s and what I see here are a lot of blah blah blah.

It's the final result what really matters. And the photographer, of course.

I think you all love to see papers and graphics. Nice specs, nice data... Now show me your pictures proving that Bayer sensor is better than the Foveon or vice-versa.

Some people here are acting like monks discussing sex. A lot of theory and a deep lack in practice.







at 10/31/2009 8:47:36 AM, FoveonFanboy said:
Geez, what a bunch hoopla...."Just Me" took issue with the statements I made. The Sigma line of cameras are at an infant stage. They have a long way to go, its true. But I believe that some people cannot see the differences in photo quality. I run into them everyday, as well as individuals that have quite a keen eye. Now this is a battle of semantics and individual tastes to be sure. But "Just Me" ya gotta admit quite a few people do profess to see something very good in Foveon images. The fact that you can't sucks, for you anyway. I am sorry about that, you can teach a person to have an eye. But I gotta say, I view lots of pictures from lots of cameras, film and the like. I teach digital photography, I see thousands of images. The quality of the photos from the Fovenon sensored cameras are quite amazing for such a limited amount of photosites. It doesn't have to start a war, just enjoy it for what it is........

FF



at 10/31/2009 8:51:16 AM, FoveonFanboy said:
Oh, one more thing "Just Me" I think for individuals tired of the flat 2d look that most digital bayered sensored cameras provide the film-like look and quality of the Foveon sensor is a gift from technical heaven..........



at 10/31/2009 9:00:47 AM, FoveonFanboy said:
Oh and "Just Me" just shot all day with a 5dMkii and the DP2. Image for image I gotta say that the Dynamic range and the Photo quality were and exact tie at images output at 12x18 inches. Epson 3800, premium luster. Now this is happening for 650$ in a camrea that really can fit in a pocket. The 5dMkii owner was a little long in the face when the printing was all done. The 5DMkii of course outclassed the DP2 in every other department as expected. But read the Nov Shutterbug review of the DP2. Read the nice little story (the last paragraph) of the review. The reviewer slipped photos from the DP2 in with the likes of the 5dMkii and Nikons D3 series cameras. The reviewer stated outright that the DP2 did more than hold its own with these highend icons. This is happening with a fairly underdeveloped sensor technology. 4.7 million photosites only vs. 21 million photosites. It does seem to make the Foveon sensors somewhat remarkable. IMHO.....

FF



at 10/31/2009 1:02:14 PM, just me said:
Patrick Bellard - I never said Sigma gave gifts to the public. I said that some of the so called 'fans' are affiliated with Sigma and work in the Sigma booth at those shows. They're more than just fans, they're shills.


FoveonFanboy - I see thousands of images too, and to be blunt, the SD14 is not competitive with current DSLRs, in both image quality and the camera itself.

The term 'film-like' is meaningless. There are so many different types of film, each with its own look. Which type of film is the SD14 like? And why would anyone want 'film-like' when film is actually less accurate and less capable than digital?

It reminds me of vinyl records versus CDs, when people tried to claim that records sound better. I guess if you like scratches and pops they are.

As for your dynamic range test, if you're finding that the SD14 and 5D II have similar dynamic range, you are doing something very very wrong with the 5DII. No wonder you think the SD14 is so good, you don't know how to properly use the 5D.

It's impossible for the SD14 to match the dynamic range of the 5D2 because the sensor in the 5D2 has a dynamic range that exceeds it's own 14 bit A/D converter (at nearly 15 stops), whereas the SD14 has a sensor that has a dynamic range limited to 10 bits (approximately 10 stops). See Roger Clark's analysis of Canon equipment, the actual spec sheet of the Foveon sensor and Imaging Resource's dynamic range tests for further information (I'd provide a link but I can't).



at 11/1/2009 7:10:21 PM, Foveon Fanboy said:
You know I am just amused here.... pixel peepers kill me. I am saying yes, the Foveon sensored DP2 held its own in several areas. Dynamic range was one of them. Is it as good as the 5d Mkii in all areas? not in the least. I noticed the 5d mkii was struggling with blown highlights under the same lighting conditions that the DP2 was.... evaluative metering. Going to spot and AEL took care of several issues for both cameras. I am claiming that the Foveon sensors are very good, very good indeed. I have shot Canon digital products for the last 8 years. I enjoy most cameras, for what they are and what they can do. I am suprised at the angst demonstrated by Bayer enthusiasts where the Foveon sensor is concerned. You can say what you like, Foveon sensors are remarkable where image quality is concerned. I am not saying that Bayer sensors can't produce beautiful photos, they can.. but so can the Foveon sensor. They shine in different areas though, I am sorry if you can't see the very flat 2d cartoon looking results that are now passing for photography even in major publications. Almost painting like..Foveon produces images that look different to me. I am not alone in this.. so really, I could care less if others want to trash this technology. I love it...but I am a fan of many cams. I am loving my access to the 5dMkii. I may buy one.. but for the money and the subject matter I shoot, and the portability of the DP2 and the image sizes I print what a bargain!!!! the DP2 is... I am sorry, but I stand by the assessment anecdotal or not. The 5dMkii is not a cloud an sky machine. As a Bayer sensored camera with 21 megapixels is shines resolution wise. Incredibly so does the 4.7 megapixel DP2. The dyamic range of the 5dMkii is not improved drastically over my XSI or the DP2. Sorry if you can't believe that. As for picture quality, I am not the only one comparing the sensor in the DP2 with higher end cameras and finding the same results. The bottom line for me is the size, IQ, portability and the look of the images. It is different somehow, hard to put into words. I like the images from this cam. Buy the way, I got rid of all my vinyls long ago, I can't tolerate pops and clicks.



FF



at 11/1/2009 7:14:35 PM, Foveon Fanboy said:
I my gawd, I just read the claim of 15 stops of dynamic range for the 5dMkii, please post the links to that claim. You must be joking.. please provide the links to that claim. I would like to read up..

FF



at 11/2/2009 4:05:50 PM, just me said:
Flat 2D cartoon looking results? The only way you'll get that is if you do that deliberately.

Foveon does produce a different look and if you like it, that's great. Making images you like is what it's all about.

What I have a problem with are the ridiculous claims that are so easily proven to be false. It reminds me of the flat Earth society or the people who think the moon landings were faked. Those people are SO convinced of their beliefs and consider anyone who says otherwise to be a lunatic or part of the conspiracy (sound familiar?), despite the overwhelming evidence that proves them to be so very wrong.

As for the 15 stop claim, the definitive work is Roger Clark's clarkvision web site, and in particular, the Digital Sensor Performance Summary page. Links are blocked here but it should be very easy to find (it's in the Image Detail section of his site). And if you're wondering who he is, check his bio page. He has a Ph.D. from MIT and works at NASA designing sensors for spacecraft, with over 200 published peer reviewed papers.

Roger has done an extensive quantitative analysis of a number of sensors by measuring the photon well capacity and read noise of the sensor itself (which is how you measure dynamic range of the sensor). This is different than evaluating photos because it completely eliminates all of the effects of raw processing, tone curves, gamma, display or print limitations and the biggie, human judgement and bias.

Based on his measurements, the sensor in the 5D II has a photon well capacity of about 66k electrons and a read noise of about of 2.5 electrons, which is 14.7 stops of dynamic range (Table 2). You won't actually get that in a photo because the 14 bit A/D converter limits it to 14 stops and other factors reduce it even further. What that means is that the electronics in the 5D II is the limiting factor, not the sensor. Figure 4 shows how it compares with sensors in other cameras, and where the limit of the 12 and 14 bit A/D converters is.

At Foveon's site, the spec sheet of the 4.7 megapixel Foveon F13 sensor states that its dynamic range is 62 dB, or about 10 stops. Since the SD14 has a 12 bit A/D converter which is capable of 12 stops, the sensor is the limiting factor, not the electronics. There are a few threads on dpreview where people have measured the dynamic range on the SD14 by analyzing the raw data and they also get about 10 stops, matching what Foveon's spec states.





at 11/3/2009 3:53:23 PM, Foveon Fanboy said:
I am amazed at this Forensic approach to photography. Thank God that the viewers of images don't require the background knowledge of the sensor manufacturer to enjoy the results they produce. I am an OCD of the nth magnatude. It is a fruitless pursuit to debate taste. So, I have to agree with you. Make the images you enjoy. I think that Foveon is in an infant state backed by and inept camera manufacturer. I still maintain that the images from these sensors have a unique look. If I were the only one saying this I would have to doubt myself. I am not.....I am hoping that this approach will develop (no pun intended) into something great.

Best Wishes All
FF



at 11/3/2009 8:28:06 PM, Red said:
Interesting... JustMe must have orgasms while looking at datasheets, specs and Ph.D. I see something here... hahaha

I received My D100 and I sent it back. Compared to the SD14 it's a real piece of crap. Thanks god thw seller accepted it back. Got a D300S from him. Of course it's much better than the old one, but the SD14 pictures are still better looking and this is all I need to know.

My idea was to get a good Nikon and sell the SD14, but now I decided to keep it. I dont need to see noise figures, charts, neither the 200 papers that genius wrote. Neither the 66k electrons blah blah blah from the Canon. Even less the five trillions stops.

I have the impression that you're working for the author... lol ! Just kidding... Well not entirely =)


Let me tell you a short story:

I had a '96 Grand Sport Corvette. It's manual said the LT4 engine has 330HP and lots of other cool things.

I still have my '75 Porsche 930 with a darn good 260 HP engine and it's a far superior car, in any aspect.

Got the idea ? Or would you like me to draw ?

Papers and specs may look nice but....

Foveon rules.



at 11/4/2009 4:10:16 PM, Inquisitor said:
Is this post active again ?
I see that Red has a very caustic sense of humour. I like this guy ! Specially the parallelism with cars and sensors. Brilliant. I'm still laughing !


"Interesting... JustMe must have orgasms while looking at datasheets, specs and Ph.D. I see something here... hahaha"

Lol ! I agree 100% bud !










at 11/4/2009 9:32:54 PM, Foveon Fanboy said:
I gotta say, I have been working with the 5DMkii. Its true, it is highly resolute. It can creat silky clean images. The dynamic range on the 5DMkii is very good.... It costs 2700$ for the body. The DP2 I shoot creates amazing silky clean images. It seems to have an incredible 3d look in some of the images. I can't explain it. The dynamic range is very good. The images are very sharp and clean. It costs 650$ body and lens. I can't wait to see photos coming from this camera after each shoot. If you need portability and incredible IQ consider this unit. It is not a speed shooter or sports camera. Thoughtful deliberate photograpy is the name of the game with this camera.

FF



at 11/5/2009 8:20:04 PM, Foveon Fanboy said:
The November Shutterbug review for Sigma's DP2 ended with this little story.

In covering a recent photo trek at Arches National Park in Moab, Utah, that was mentored by four remarkably adept high-end professional photographers, we concluded the event by projecting all our best images on the big screen. Just for fun I submitted half a dozen pictures I’d shot with the DP2, putting them up against superb-quality images taken with the likes of the Nikon D700, D3X, and the Canon EOS 5D Mark II. To say that the DP2 images held their own is an understatement—a couple of the pros even asked me what lens I’d used and were astounded when I showed them the camera.

Ya know, thats a helluva claim. If true, it really shows some of what some individuals are trying to tell the Bayer sensor neo-phytes. I mean give the Foveons their due. Why freak out about something that is photographically good for all of us. IE MORE CHOICE!

FF





at 11/18/2009 4:06:41 PM, st.edwards said:
amazing that this thread is still alive & kicking..the sd14 isn't obtainable now @ $350 & the sd15 is still not released..
2 weeks ago, with photo projects on a dwindle I was about to let my sleeping SD9 go & was thinking of the C 7D (for its video) when a photo-stills project came along & thought of comparing it with my son's Oly e-510, the product is colorful ice-cream (& sundries)-after just the 1st set( of shooting & eating)it's a re-revelation (I knew this 7 yrs ago) and although I can see (a tiny) bit more detail with the e-510, the colors- in film parlance on a light-table,is like looking at (old)ektachrome 100 & velvia 50...my mint sd9 (actually my 1st DSLR!) with all its quirks & foibles is a keeper after all at least for table-top product shots (& to think it almost got sold for $150!)

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