Canon's Medium Format

[CarlTN]

So arguing that the DP2, which itself is still just a 4.7mp camera (or even the SD1, which is a much higher resolution Foveon), is potentially equivalent to a 39mp camera, is gravely missing the point of having a truly higher resolution sensor (in luminance terms...luminace is where detail comes from, color CAN be of much lower spatial resolution so long as your luminance information is high...as a matter of fact, this is actually a standard practice in astrophotography, to image at high resolution in luminance, then when you switch to RGB filters, you bin 2x2 or 3x3, which increases your sensitivity, and reduces your resolution by 4x or 9x...and your never the wiser when looking at the final blended result). It buys into the very misleading hype that Sigma spews, which I believe is ultimately, in the long term, going to damage their reputation and hurt Foveon (because as more people try to produce images with a 4.7mp or 15mp Foveon sensor that compare to even the regular old D800, let alone the D800E or the 645D, and realize they simply cannot...they are either going to ditch Foveon and go back to bayer type sensors, or they are going to begin badmouthing Foveon.)

Nobody said the first generation Foveon sensor is equal to 39 MP. Jrista, again you learn about what you're interested in, but this leaves a lot of facts for you to miss.

When I mentioned the "new DP2", I was referring to this...it's called the Quattro.

http://www.sigma-global.com/en/cameras/dp-series/

...And it's most definitely more resolution than the SD-1...it's a new sensor with more pixels. Just exactly how many pixels it is, is kind of unclear. I think Sigma don't mind that it is unclear...lol. The actual pixel dimensions of the RAW image, might be 19 MP, or might be more. For some reason it can produce JPEGs that are 7680 x 5120 = 38.3 MP.

To argue about what outresolves what, on such a new product, is a waste of time in any case.

I try to speak about what I have had experience with. I've owned the original DP2, and it most certainly had more resolution than its native 4.6 MP image. As I said, it could easily scale to about 25 MP, and still look sharp enough to me for a print at 300 ppi.

So there's no reason to start bashing Sigma, and talking about what "TROUNCES" what. Nobody thinks a crop sensor is ever going to be "better" than a full frame sensor...other than you and your 7D . Everybody knows nothing compares to the mighty 7D!

 

[vscd]

@jrista

Yepp, you mixed some things. The first FoveOns were 5Mpixel on three Layers, which (could) be summed up to 15MPixel. The next generation was the Merrill, where about 15MPixel on 3 Layers can be counted to 45MPixel. The new Quatto Design ist again 3layered, but just the blue one get's 19MPixel, where the other 2 are just about 5 MPixel each. Now happy counting

At the End, the results are crucial.

It may have 45 million photodiodes, but that is not the same as megapixels, and I really wish Sigma would stop being so misleading.

This is of course confusing, but it's not a lie, because... let's define a pixel. You refer to it as a Pixel is the Picture which comes out from the cam. The Pixels from the Sensor are something different... you could also count each layer as a single Pixel, because it has an own wired output and the information is capsulated within this *single* Lighttrap. Remember the Nikon D2X (or was it the D1x?), there the Pixels were halfsized, so what do you count? It's some kind of definition. The Sigmapeople have the same "problem" as Intel had 10 years ago... recognizing that Megahertz has nothing to do with speed, but the people don't know this. So you have to catch them with Numbers they understand.

Furthermore, the D800 and 645D both have more information to start with. They are resolving details that are not even present in the SD1 image at all, despite it's sharpness

No, they DON'T, that's what the image should have told you. I could resize the Sigma-Picture 4 Times and have more resolution, but not more information.

A light sharpening filter can deal with the softness in a few seconds, and then the SD1 is at a real disadvantage.

Please try and proove me wrong, the RAW-Data is available for download @dpreview.com

By the way, the Size of the photodiodes are of course really important, especially on lowlight, but the technology solves some of the problems. On the paper no one could beat my old 5D with ca. 8.2 Microns, but in reality your 1DX would run circles around it 8)

 

[Ellen Schmidtee]

The whole "eqivalent megapixels" deal that Sigma uses is also very misleading. Currently, today, megapixel counts are based on output image widthxheight. A 15mp Sigma Foveon is 15mp, in terms of actual megapixels stored in the output JPED image or a JPEG that you can create from RAW. It may have 45 million photodiodes, but that is not the same as megapixels, and I really wish Sigma would stop being so misleading.

No more misleading than stating a sensor has so many megapixels, when each photodiode samples one color, and the other two are interpolated in the JPEG.

 

[privatebydesign]

The whole "eqivalent megapixels" deal that Sigma uses is also very misleading. Currently, today, megapixel counts are based on output image widthxheight. A 15mp Sigma Foveon is 15mp, in terms of actual megapixels stored in the output JPED image or a JPEG that you can create from RAW. It may have 45 million photodiodes, but that is not the same as megapixels, and I really wish Sigma would stop being so misleading.

No more misleading than stating a sensor has so many megapixels, when each photodiode samples one color, and the other two are interpolated in the JPEG.

Well not really. Each pixel has its own brightness level, so resolves its own detail, the colour of each pixel is a result of the surounding pixels, but not the brightness. The MP count of a Bayer arrayed sensor is a truthful reflection of the actual individual brightness measurements.

In essence, the colour might be off but the detail isn't, just look at the Monochrome Leica to realise that.

 

[neuroanatomist]

...let's define a pixel. You refer to it as a Pixel is the Picture which comes out from the cam. The Pixels from the Sensor are something different... you could also count each layer as a single Pixel

No more misleading than stating a sensor has so many megapixels, when each photodiode samples one color, and the other two are interpolated in the JPEG.

A pixel is best defined as a unit of spatial information. Interpolation of color information does not change the underlying luminance or spatial information. Counting multiple layers of a given spatial element as separate pixels is misleading (intentionally so, on Sigma's part). The Sigma DP2 has a 4.6 MP sensor, not a 14 MP sensor. One could argue that Bayer-type sensors do not deliver their full potential spatial resolution due to the blurring from the OLPF (AA filter). However, with a properly designed OLPF (one that blurs spatial frequencies above the Nyquist limit for the underlying CMOS sensor) and proper application of sharpening in post-processing, there's no significant loss of spatial resolution from the OLPF (as shown by comparisons of D800E images to properly-sharpened D800 images, although technically the D800E does have an OLPF, just one that's designed not to introduce blur).

Some of my Zeiss microscope cameras use an older Sony 1.3 MP CCD sensor with no microlenses. Unlike dSLR sensors, the Bayer mask is physically separate from the CCD. The camera can take a 'standard' image, analogous to a dSLR picture, that delivers a 1.3 MP image with the color values interpolated across neighboring pixels. The camera can also piezoelectrically move the CCD in 1-pixel increments, such that with three successive images each pixel is directly capturing R/G/B and no color interpolation is needed…that means the color is more accurate, but it's still just a 1.3 MP image. Interestingly, the camera can also move the CCD in sub-pixel increments as either a 2x2 or a 3x3 array within the space of a single pixel – that results in an increase in real spatial resolution, producing a 5 MP or a 13 MP image, respectively, from that 1.3 MP sensor. Of course, gapless microlenses would obviate the benefit of moving the sensor, and the process only works with static subjects (fixed specimens), since a 13 MP image without color interpolation means capturing 27 separate images and merging them spatially and chromatically.

 

[jrista]

So arguing that the DP2, which itself is still just a 4.7mp camera (or even the SD1, which is a much higher resolution Foveon), is potentially equivalent to a 39mp camera, is gravely missing the point of having a truly higher resolution sensor (in luminance terms...luminace is where detail comes from, color CAN be of much lower spatial resolution so long as your luminance information is high...as a matter of fact, this is actually a standard practice in astrophotography, to image at high resolution in luminance, then when you switch to RGB filters, you bin 2x2 or 3x3, which increases your sensitivity, and reduces your resolution by 4x or 9x...and your never the wiser when looking at the final blended result). It buys into the very misleading hype that Sigma spews, which I believe is ultimately, in the long term, going to damage their reputation and hurt Foveon (because as more people try to produce images with a 4.7mp or 15mp Foveon sensor that compare to even the regular old D800, let alone the D800E or the 645D, and realize they simply cannot...they are either going to ditch Foveon and go back to bayer type sensors, or they are going to begin badmouthing Foveon.)

Nobody said the first generation Foveon sensor is equal to 39 MP. Jrista, again you learn about what you're interested in, but this leaves a lot of facts for you to miss.

When I mentioned the "new DP2", I was referring to this...it's called the Quattro.

http://www.sigma-global.com/en/cameras/dp-series/

...And it's most definitely more resolution than the SD-1...it's a new sensor with more pixels. Just exactly how many pixels it is, is kind of unclear. I think Sigma don't mind that it is unclear...lol. The actual pixel dimensions of the RAW image, might be 19 MP, or might be more. For some reason it can produce JPEGs that are 7680 x 5120 = 38.3 MP.

To argue about what outresolves what, on such a new product, is a waste of time in any case.

I try to speak about what I have had experience with. I've owned the original DP2, and it most certainly had more resolution than its native 4.6 MP image. As I said, it could easily scale to about 25 MP, and still look sharp enough to me for a print at 300 ppi.

So there's no reason to start bashing Sigma, and talking about what "TROUNCES" what. Nobody thinks a crop sensor is ever going to be "better" than a full frame sensor...other than you and your 7D . Everybody knows nothing compares to the mighty 7D!

I don't know where you guys are getting your info. On your own site, the DP2 is listed as having 29mp effective (non-masked) "photo detectors", which are the same thing as a photodiode. From the dp-series link:

Color Photo Detectors Total Pixels: Approx.33MP, Effective Pixels: Approx.29MP

That is 29 million PHOTODIODES. That means, from a SPATIAL standpoint (actual resolving power), you have 29/3 million PIXELS (actual square areas on the sensor that are light sensitive), or 9.7mp. The DP2 that you are referring to is a TEN MEGAPIXEL sensor. Not only that, it is a 10mp APS-C sized sensor, so were talking pretty small pixels.

I'm sorry, but it doesn't matter how good those pixels are...there is no way, physically, that they could ever compare to the 36.3mp of a D800 nor the 40mp of the 645D. Spatially, from a luminance (detail) perspective, there is no loss of data or resolution in a bayer array. There is only, ONLY, a loss of color data or color spatial resolution. The loss of spatial color detail is a bit of a detractor for bayer type sensors, it hurts their color fidelity a little bit, however it is not enough of a detractor to warrant calling a 9.7mp Foveon as good as a 39mp bayer. The FULL detail luminance from a bayer is more than enough to offset the loss in color detail.

Neuro has explained how a properly designed OLPF (which is usually the case these days, even leaning towards the slightly weak side more often than not), despite blurring high frequency data, is not a huge detractor for bayer sensors as OLPF's blur predictably and consistently across the area of the sensor, meaning a light sharpening filter in post usually reverses the softening impact of an OLPF.

The whole "eqivalent megapixels" deal that Sigma uses is also very misleading. Currently, today, megapixel counts are based on output image widthxheight. A 15mp Sigma Foveon is 15mp, in terms of actual megapixels stored in the output JPED image or a JPEG that you can create from RAW. It may have 45 million photodiodes, but that is not the same as megapixels, and I really wish Sigma would stop being so misleading.

No more misleading than stating a sensor has so many megapixels, when each photodiode samples one color, and the other two are interpolated in the JPEG.

Your misunderstanding. Every bayer pixel may have only one color, but regardless of color, every pixel receives "light". This is why the spatial resolution of a bayer sensor is so high, and why a D800 is capable of resolving so much detail. If you convert a bayer sensor's data to monochrome, you effectively have just the full detail luminance. Advanced demosaicing algorithms like AHDD are explicitly designed to preserve as much luminance detail as possible, while effectively distributing color data to avoid mazing artifacts and other demosiacing quirks. A bayer sensor needs no interpolation from a luminance standpoint, they only need interpolation from a color standpoint. Bayer sensors have nearly their full resolution in terms of luminance, and since luminance is really what carries your fine detail, they DO have FAR more resolution than any Foveon on the market today, including the SD1.

This isn't missleading, it's how the physics and mathematics of interpolation work. Interpolation algorithms like AHDD are actually capable of producing crisper, smoother, sharper results with a bayer than your standard, basic demosaicing algorithm, and AHDD is pretty ubiquitous these days (LR/ACR use it, Adobe Aperture uses it, and it's a demosaicing option in most Linux RAW editors like RawThearapy and Darktable.) AHDD is even used in lower level tools, often used for astrophotography, like DeepSpaceStacker, Iris, and PixInsight.

The only loss with a bayer type sensor is in terms of color spatial resolution and color fidelity. The most obvious of those is really color fidelity, as when chrominance is blended with luminance, our eyes can't really tell the difference, or at least the difference is small enough that it isn't an issue unless you are directly comparing, side-by-side, a Foveon and Bayer image with the same image dimensions (in other words, if you had a 10mp bayer and a 10mp Foveon, then you would be able to tell that the Foveon had slightly better color microcontrast and better color fidelity...however when comparing a 35 or 40mp bayer to a 10mp Foveon, the only visible difference MIGHT be sharpness...that would depend on the strength or presence of an AA filter.)

 

[Sporgon]

If you convert a bayer sensor's data to monochrome, you effectively have just the full detail luminance.

If you can just expand on that a little Jon. When you say 'you' are you referring to the manufacturers setting it up this way ( like the Leica monochrome), or the user converting the RAW to B&W ?

 

[jrista]

@jrista

Yepp, you mixed some things. The first FoveOns were 5Mpixel on three Layers, which (could) be summed up to 15MPixel. The next generation was the Merrill, where about 15MPixel on 3 Layers can be counted to 45MPixel. The new Quatto Design ist again 3layered, but just the blue one get's 19MPixel, where the other 2 are just about 5 MPixel each. Now happy counting

At the End, the results are crucial.

Actually, the results aren't all that crucial. You don't have a 19mp sensor just because the blues are higher resolution. You get something around the average of the spatial resolutions of all three colors. Red has the lowest weight, green actually has the highest weight because it is where the bulk of light entering a camera usually comes from. Blue has the second highest weight. You can increase luminance detail in blue, but since blue is inherently a lesser component of visible light, and since our eyes are less sensitive to blues, green dominates. The bulk of the luminance detail is going to come from green, and since that is a lower resolution than the blues, you don't have a 20mp sensor. If you just take the averages, you have 9.7mp. You might have somewhere between 10-15mp, depending on exactly how the Foveon color information is processed and, for lack of a better word, interpolated, to produce a final image. Either way, you still aren't getting any more spatial resolution than the SD1 had years ago, and honestly I'd prefer the SD1 design, rather than the quattro design (becase at least with the SD1, your spatial resolution was exact, not some blend of higher and lower frequency pixel spacing.)

Sigma is still being very misleading by saying that you get 39mp. They are working some quirky imaginary mathematical magic as well, because assuming you just added up the resolutions of each pixel, you get 19.6+4.9+4.9, which is 29.4mp. How they get to 39mp is beyond me, however I suspect they are using some arbitrary means of measuring an upscaled image in relation to bayer images like they have done in the past. Simple fact of the matter is, upscaling and bayer interpolation (especially with AHDD) are NOT the same thing, and do NOT produce the same results. Sigma is probably comparing images demosaiced with your standard 2x2 intersection-based demosaicing to upscaled Foveon images, which is intentionally putting bayer at a significant disadvantage that ignores the most common and effective means of demosaicing.

It may have 45 million photodiodes, but that is not the same as megapixels, and I really wish Sigma would stop being so misleading.

This is of course confusing, but it's not a lie, because... let's define a pixel. You refer to it as a Pixel is the Picture which comes out from the cam. The Pixels from the Sensor are something different... you could also count each layer as a single Pixel, because it has an own wired output and the information is capsulated within this *single* Lighttrap. Remember the Nikon D2X (or was it the D1x?), there the Pixels were halfsized, so what do you count? It's some kind of definition. The Sigmapeople have the same "problem" as Intel had 10 years ago... recognizing that Megahertz has nothing to do with speed, but the people don't know this. So you have to catch them with Numbers they understand.

A pixel is a spatial measure, two dimensional, not three dimensional. You can define pixels in many ways, however as far as bayer is concerned, it's all the same. You can measure the individual r, g, and b pixels in a sensor. Assuming you ignore the masked pixels, you will usually get one extra row and column at the edges of the RAW image data as compared to the interpolated image. So, if you have a camera with 5184x3456 (i.e. 1D X) pixels, that is the EXACT pixel count as far as exported TIFF or JPEG images go. The actual RAW pixel count, ignoring the masked border pixels, would be 5186x3458, as you need that extra set of rows and columns on the outer edge in order to perform interpolation. The actual true RAW pixel dimensions are greater, around 5212x3466 when you do include the masked border pixels (which are used for sensor black and white point calibration).

Regardless of how you slice it, a "pixel" in bayer is a direct unit of two-dimensional SPATIAL measure. A "pixel" in Foveon, the way Sigma defines it, is a three-dimensional measure of both spatial detail and color depth. If you want to compare Foveon to Bayer, you have to remove that third color depth dimension, otherwise you are comparing apples to oranges. Spatially, Foveon sensors have, historically, been significantly lower resolution than bayer sensors. This is no myth, no trickery, there isn't even any anti-Foveon here. As I've said, I love the Foveon concept, I just think that Foveon in the hands of Sigma is in the wrong hands, and I think the way Sigma markets Foveon is so misleading that it ramps up prospective buyers hopes to levels that simply cannot be met. (Either that, or you get gullible saps who buy so fully into Sigma's misleading concept that they are missing the forest for the trees, and therefor missing out on the kind of raw, unmitigated resolving power you can get with some current bayer sensors...which actually includes both the 5D III and D800, probably also the 6D, and for sure all current medium format sensors on the market without question.)

Furthermore, the D800 and 645D both have more information to start with. They are resolving details that are not even present in the SD1 image at all, despite it's sharpness

No, they DON'T, that's what the image should have told you. I could resize the Sigma-Picture 4 Times and have more resolution, but not more information.

Your conflating two separate concepts. Resolution is an overloaded word, and some of it's "overloads" are invalid. I try to be very specific when I use words like resolution. When I say resolution in this context, I try to always make it very clear that I am talking about resolving power and spatial resolution. These terms refer to very well understood concepts in the world of imaging, and describe a very specific process where by something with a given area is divided into certain discrete elements...such as a real image projected onto a sensor by a lens being "resolved" by each pixel.

What you are referring to is one of the invalid uses of resolution, which refers to image dimensions. Simply upscaling an image does not give you more resolution...it gives you more pixels, but your resolution has not actually increased. By upscaling, you enlarge everything, including the smallest discernible element of detail, such that those smallest elements are also larger. That is not increasing resolution...it is simply increasing the total number of pixels and enlarging your images dimensionally. I rarely ever use the word "resolution" to refer to changes in image dimensions. I usually use the term "image dimensions", or refer to concepts like upscaling or downsampling, to refer to changes in image dimensions.

The resolution I am talking about is not the "resolution" your are talking about. Upscaling an image does not give you more resolution...it simply gives you more pixels, and changes the ratio of pixels to detail. Luminance detail, I might add...when you upscale a Foveon image, you aren't just blurring chrominance information (as is the case with bayer interpolation)...you are ALSO blurring luminance information (which is NOT the case with bayer interpolation...you keep your full luminance information at each pixel.)

So you are correct about not having more information after upscaling.

A light sharpening filter can deal with the softness in a few seconds, and then the SD1 is at a real disadvantage.

Please try and proove me wrong, the RAW-Data is available for download @dpreview.com

By the way, the Size of the photodiodes are of course really important, especially on lowlight, but the technology solves some of the problems. On the paper no one could beat my old 5D with ca. 8.2 Microns, but in reality your 1DX would run circles around it 8)

Your argument is a classic fallacy...to claim that technological improvements will only benefit one type of technology. Technological improvements can indeed help Foveon, but at the same time, MASSIVE strides have been and will continue to be made for bayer type sensors as well. Foveon isn't going to be gaining technological advancements in leaps and bounds and suddenly end up well ahead of bayer...it just isn't going to happen.

In this case, the reason the 1D X would run circles around the 5D does not actually have anything to do with pixel size. The 5DC is actually still an excellent performer. I know a few wedding photographers who LOVE their 5DCs, they still produce wonderful images. Technologically, they have high read noise (actually quite high), so the images from a 5DC cannot be pushed around like those from a 1D X or even a 5D III or 6D. The CDS technology used in the 5DC isn't as good as it is today. The individual color filters in the bayer CFA are stronger in the 5DC, which improves native color fidelity, but reduces total sensor Q.E.

So yes, technology does solve some problems. If the Foveon was in the hands of Canon or Sony, I believe it could rapidly become a major contender in the sensor market. I do not believe it would ever offer as much spatial resolution (i.e. true resolving power) as any bayer...as Foveon improves, so too will bayer sensors, and bayer will always have the lead in terms of spatial resolution, assuming your aim is to keep Foveon noise levels as low as bayer levels. Spatially, Foveon could compete directly with bayer if you simply ignored noise levels, however because the red layer is at the bottom, despite silicon's greater transparency to red, your still losing a lot of light by the time the red photodiode senses anything. A spatially-equivalent Foveon is going to be a very noisy sensor.

I think the only way your going to get a true "full color fidelity per pixel" sensor that is actually better than bayer would be if something like TriCCD came along again. Three separate sensors with single-color color filters on them, which receive light from a special prism where each sensor gets a FULL compliment of light of it's given color. You then have full sensitivity, full spatial resolution, in three (or, as should be possible, more) full colors. You would then simply need to convert each RAW color layer into R,G, and B pixels in an output image, no interpolation required (like Foveon, but without the sensitivity and noise issues.) Such a system would be rather bulky, but I do think it would be ideal for those who want everything to be the absolute best. Foveon is just another compromise....spatial resolution for color fidelity, just like bayer is a compromise: color fidelity for spatial resolution.

 

[jrista]

If you convert a bayer sensor's data to monochrome, you effectively have just the full detail luminance.

If you can just expand on that a little Jon. When you say 'you' are you referring to the manufacturers setting it up this way ( like the Leica monochrome), or the user converting the RAW to B&W ?

I mean you as in the "you" who is reading my words.

You can use astrophotography editors to read RAW images directly. If you used something like LR or ACR, if you convert to grayscale that is post-demosaicing, so you really wouldn't gain the same benefit. With something like Iris, you can simply read out a RAW image as monochrome data. You might get slight artifacting this way...silicon really is not very sensitive to blue at all, so depending on the exact camera you are using, the blue pixels might end up a bit darker. I recently purchased a tool called PixInsight, an astrophotography processing tool (exceptionally powerful). PixInsight has something called PixelMath, which allows you to run just about any algorithm you can imagine on your images. If you have a blue darkening problem when converting a RAW image directly to luminance, you could easily apply some pixel math to reweight some luminance information, stealing a little bit from green and adding it to blue. Or you could artificially apply some digital amplification to just the blue pixels, which would make them a little noisier, but normalize the brightness.

Regardless of how you correct any blue deficiencies (which, BTW, would also be present in a Foveon sensor, as silicon is silicon), Bayer sensors generally gather roughly the same average amount of light at every sensor pixel. Absent any color, that is your full resolution DETAIL...and it really doesn't need any interpolation, all it might need is some massaging to normalize luminance levels in post. Blue is just a noisy channel because of lower natural sensitivity levels...we've all been living with that fact ever since we started using digital cameras. Everyone knows about it from the noise in their blue skies or the blue paint on that car or the blue dye in that girls hair.

 

[neuroanatomist]

...or the blue dye in that girls hair.

Does it have to be a girl?


EOS 5D Mark II, EF 70-200mm f/2.8L IS II USM @ 70mm, 1/400 s, f/2.8, ISO 100
Taken on Shamian Island in Guangzhou, China.

 

[jrista]

...or the blue dye in that girls hair.

Does it have to be a girl?


EOS 5D Mark II, EF 70-200mm f/2.8L IS II USM @ 70mm, 1/400 s, f/2.8, ISO 100
Taken on Shamian Island in Guangzhou, China.

Clearly not! That is some badass blue hair, too! Strait out of an anime into real life kind of blue hair.

 

[PVS]

My girlfriend bought 5Dc couple of years ago and I bought 5Dmk3 couple of months ago. We print mostly on fuji machines on fuji luster paper. We have bunch of Lenses. Shitloads of MF& 135 cameras too. 2 MF/Lf scanners and one dedicated 35mm scanner. Both of us make our living from photography and live photography everyday. On assignments both of us shoot nikons, canons. We love every camera which shuffles in our hands, be it fuji, sony, olympus or canikon.
In our bedroom we never discuss the issues posted on previous page of this thread. In our kitchen we never discuss the very same issues. When we have drinks with our colleagues we never discuss these same issues.
What have this world come to?

Haven't seen much girls around this forum.

 

[CarlTN]

My girlfriend bought 5Dc couple of years ago and I bought 5Dmk3 couple of months ago. We print mostly on fuji machines on fuji luster paper. We have bunch of Lenses. Shitloads of MF& 135 cameras too. 2 MF/Lf scanners and one dedicated 35mm scanner. Both of us make our living from photography and live photography everyday. On assignments both of us shoot nikons, canons. We love every camera which shuffles in our hands, be it fuji, sony, olympus or canikon.
In our bedroom we never discuss the issues posted on previous page of this thread. In our kitchen we never discuss the very same issues. When we have drinks with our colleagues we never discuss these same issues.
What have this world come to?

Haven't seen much girls around this forum.

True, there aren't many "girls" on this forum. But what does that have to do with anything? And I'm not surprised you wouldn't discuss the science behind the hardware of the cameras you use every day. It's because you aren't curious about it, it doesn't fascinate you. Or at least not both of you.

 

[CarlTN]

So arguing that the DP2, which itself is still just a 4.7mp camera (or even the SD1, which is a much higher resolution Foveon), is potentially equivalent to a 39mp camera, is gravely missing the point of having a truly higher resolution sensor (in luminance terms...luminace is where detail comes from, color CAN be of much lower spatial resolution so long as your luminance information is high...as a matter of fact, this is actually a standard practice in astrophotography, to image at high resolution in luminance, then when you switch to RGB filters, you bin 2x2 or 3x3, which increases your sensitivity, and reduces your resolution by 4x or 9x...and your never the wiser when looking at the final blended result). It buys into the very misleading hype that Sigma spews, which I believe is ultimately, in the long term, going to damage their reputation and hurt Foveon (because as more people try to produce images with a 4.7mp or 15mp Foveon sensor that compare to even the regular old D800, let alone the D800E or the 645D, and realize they simply cannot...they are either going to ditch Foveon and go back to bayer type sensors, or they are going to begin badmouthing Foveon.)

Nobody said the first generation Foveon sensor is equal to 39 MP. Jrista, again you learn about what you're interested in, but this leaves a lot of facts for you to miss.

When I mentioned the "new DP2", I was referring to this...it's called the Quattro.

http://www.sigma-global.com/en/cameras/dp-series/

...And it's most definitely more resolution than the SD-1...it's a new sensor with more pixels. Just exactly how many pixels it is, is kind of unclear. I think Sigma don't mind that it is unclear...lol. The actual pixel dimensions of the RAW image, might be 19 MP, or might be more. For some reason it can produce JPEGs that are 7680 x 5120 = 38.3 MP.

To argue about what outresolves what, on such a new product, is a waste of time in any case.

I try to speak about what I have had experience with. I've owned the original DP2, and it most certainly had more resolution than its native 4.6 MP image. As I said, it could easily scale to about 25 MP, and still look sharp enough to me for a print at 300 ppi.

So there's no reason to start bashing Sigma, and talking about what "TROUNCES" what. Nobody thinks a crop sensor is ever going to be "better" than a full frame sensor...other than you and your 7D . Everybody knows nothing compares to the mighty 7D!

I don't know where you guys are getting your info. On your own site, the DP2 is listed as having 29mp effective (non-masked) "photo detectors", which are the same thing as a photodiode. From the dp-series link:

Color Photo Detectors Total Pixels: Approx.33MP, Effective Pixels: Approx.29MP

That is 29 million PHOTODIODES. That means, from a SPATIAL standpoint (actual resolving power), you have 29/3 million PIXELS (actual square areas on the sensor that are light sensitive), or 9.7mp. The DP2 that you are referring to is a TEN MEGAPIXEL sensor. Not only that, it is a 10mp APS-C sized sensor, so were talking pretty small pixels.

I'm sorry, but it doesn't matter how good those pixels are...there is no way, physically, that they could ever compare to the 36.3mp of a D800 nor the 40mp of the 645D. Spatially, from a luminance (detail) perspective, there is no loss of data or resolution in a bayer array. There is only, ONLY, a loss of color data or color spatial resolution. The loss of spatial color detail is a bit of a detractor for bayer type sensors, it hurts their color fidelity a little bit, however it is not enough of a detractor to warrant calling a 9.7mp Foveon as good as a 39mp bayer. The FULL detail luminance from a bayer is more than enough to offset the loss in color detail.

Neuro has explained how a properly designed OLPF (which is usually the case these days, even leaning towards the slightly weak side more often than not), despite blurring high frequency data, is not a huge detractor for bayer sensors as OLPF's blur predictably and consistently across the area of the sensor, meaning a light sharpening filter in post usually reverses the softening impact of an OLPF.

The whole "eqivalent megapixels" deal that Sigma uses is also very misleading. Currently, today, megapixel counts are based on output image widthxheight. A 15mp Sigma Foveon is 15mp, in terms of actual megapixels stored in the output JPED image or a JPEG that you can create from RAW. It may have 45 million photodiodes, but that is not the same as megapixels, and I really wish Sigma would stop being so misleading.

No more misleading than stating a sensor has so many megapixels, when each photodiode samples one color, and the other two are interpolated in the JPEG.

Your misunderstanding. Every bayer pixel may have only one color, but regardless of color, every pixel receives "light". This is why the spatial resolution of a bayer sensor is so high, and why a D800 is capable of resolving so much detail. If you convert a bayer sensor's data to monochrome, you effectively have just the full detail luminance. Advanced demosaicing algorithms like AHDD are explicitly designed to preserve as much luminance detail as possible, while effectively distributing color data to avoid mazing artifacts and other demosiacing quirks. A bayer sensor needs no interpolation from a luminance standpoint, they only need interpolation from a color standpoint. Bayer sensors have nearly their full resolution in terms of luminance, and since luminance is really what carries your fine detail, they DO have FAR more resolution than any Foveon on the market today, including the SD1.

This isn't missleading, it's how the physics and mathematics of interpolation work. Interpolation algorithms like AHDD are actually capable of producing crisper, smoother, sharper results with a bayer than your standard, basic demosaicing algorithm, and AHDD is pretty ubiquitous these days (LR/ACR use it, Adobe Aperture uses it, and it's a demosaicing option in most Linux RAW editors like RawThearapy and Darktable.) AHDD is even used in lower level tools, often used for astrophotography, like DeepSpaceStacker, Iris, and PixInsight.

The only loss with a bayer type sensor is in terms of color spatial resolution and color fidelity. The most obvious of those is really color fidelity, as when chrominance is blended with luminance, our eyes can't really tell the difference, or at least the difference is small enough that it isn't an issue unless you are directly comparing, side-by-side, a Foveon and Bayer image with the same image dimensions (in other words, if you had a 10mp bayer and a 10mp Foveon, then you would be able to tell that the Foveon had slightly better color microcontrast and better color fidelity...however when comparing a 35 or 40mp bayer to a 10mp Foveon, the only visible difference MIGHT be sharpness...that would depend on the strength or presence of an AA filter.)

It's not "my own" website. If you calculate the RAW image dimensions, it is 5424 x 3616 = 19.61 MP. Obviously there is some processing and/or interpolation involved to arrive at this image size, but there it is.

I never claimed it would outresolve a D800 "spatially", I just asked if he had seen it, and that it looked interesting...especially considering it's a crop sensor. The fair comparison would be, what is the resolving power of this camera, compared to the 70D and the Exmor 24 MP 1.5x crop sensor's best output, with its best lens mounted. To compare it to a full frame, is not a fair comparison, for various obvious reasons.

You're claiming that this new Sigma camera and sensor, could not resolve more than 10 MP worth of (equivalent "bayer"?) spatial information. I submit that you are jumping to conclusions, and they are quite possibly in error. Let's wait and see how it does when tested, rather than approaching a new product with a closed mind, and conclusions drawn...because of an unapologetic bias against the design, and the manufacturer.

It's not as if Canon have not explored their own foveon-type sensor ideas, all mockery aside.

 

[jrista]

It's not "my own" website.

I know it wasn't your own...but it was the one "you" linked.

If you calculate the RAW image dimensions, it is 5424 x 3616 = 19.61 MP. Obviously there is some processing and/or interpolation involved to arrive at this image size, but there it is.

That would only be the dimensions of the blue channel. The red and green channels are 4.9mp. When you actually render the RAW to screen, your effective resolution is going to be much closer to the average of those three channels, which is ~10mp.

I never claimed it would outresolve a D800 "spatially", I just asked if he had seen it, and that it looked interesting...especially considering it's a crop sensor. The fair comparison would be, what is the resolving power of this camera, compared to the 70D and the Exmor 24 MP 1.5x crop sensor's best output, with its best lens mounted. To compare it to a full frame, is not a fair comparison, for various obvious reasons.

True, you personally did not. I was kind of trying to respond to the whole group of you stating that the DP2 had an effective resolution of "39mp" and that the DPR sample images somehow proved that. I wasn't exactly trying to single you out like that. That said, I do think the "evidence" that has been put forward so far by everyone defending Foveon is grossly misinterpreting the information they have at their fingertips, especially the DPR sample images. One need not up or down sample anything to know, from those same images, that the D800 and 645D TROUNCE the DP2 when it comes to spatial resolution. UTTERLY TROUNCE. Splat!

You're claiming that this new Sigma camera and sensor, could not resolve more than 10 MP worth of (equivalent "bayer"?) spatial information. I submit that you are jumping to conclusions, and they are quite possibly in error. Let's wait and see how it does when tested, rather than approaching a new product with a closed mind, and conclusions drawn...because of an unapologetic bias against the design, and the manufacturer.

It isn't closed minded, it's just how the math and the theory works out. Same as the fact that the D800 gets more DR than the 5D III at ISO 100, but that the differences are negligible above ISO 400, and meaningless (either way) above ISO 800. You don't need to compare results to know that, because it's all based on the concrete, theoretical LIMITS imposed by physics.

It's not as if Canon have not explored their own foveon-type sensor ideas, all mockery aside.

Sure. As I've said, I have nothing against the concept, at all. I've said as much in several of my prior posts. I've loved the general idea of Foveon since I first read about it in one of the first couple of books I purchased on photography...years and years ago, I think before I even purchased a DSLR. My problem is really less with Foveon and the whole concept of layered photodiodes, and more with Sigma's execution and missleading statements about resolution. I understand WHY Sigma has taken the advertising route they have taken, they think it's the only way to compete with the high megapixel counts of bayer sensors, so they count each photodiode as a "pixel" (which is arguably a mendacious), in order to jack up their "megapixel" counts to comparable numeric levels.

I truly, honestly believe that does Foveon a disservice. Not everything is about megapixel count. That has clearly been demonstrated by the 1D X, which produces STELLAR results with a "mere" 18 megapixels. I really think Foveon, if marketed properly, could stand on it's own despite it's lower spatial resolution. The color fidelity benefit is nothing to shake a stick at, it's really Foveon's greatest strength, and Sigma's current advertising hardly does it justice. High resolution photography isn't even what everyone wants these days. Too many pros came out of the woodwork during the 1D III/5D II days to COMPLAIN about "too many megapixels", which is the very reason why the 1D X has a reduction in megapixel count compared to the 1Ds III.

Sigma should be marketing their DP series of cameras on the STRENGTHS of Foveon, instead of fabricating fanciful "megapixel equivalency" numbers and the like. They are undermining Foveon that way, when it IS such amazing technology. It doesn't matter that it can't produce the same kind of spatial resolution as a D800 or 645D, or even a 5D III. It has color fidelity and native sharpness our the ass, and strait out of the camera, Foveon images are better than any DSLRs with similar megapixel counts. On a same-megapixels basis, Foveon wins, and THAT is what I think is the important fact. All this trying to make it sound like Foveon is "as good as" much higher resolution bayer cameras is glossing over those strengths.

IF, someday, a Foveon with 35 real megapixels (spatially) does hit the streets, it would produce better images than a D800. Granted, by the time that day arrives, we'll probably all be using 70 megapixel bayer sensors, so Foveon still wouldn't be winning the resolution contest. But by that time, it wouldn't matter, either, as 70mp is really getting up there, and fewer people actually need that kind of resolution (maybe landscape and architectural photographers).

 

[vscd]

@jrista
I really like to interchange information with you on this objective way, but I think you're to bent to think on your decisions, you once made. I know what you're talking about and I mostly agree, but there is more than just theory... there is practice use. Even if we get out the AA-Filter of the formula, which we always did (because we choosed the D800E to compare) and we think of an optimal lense (which are rarely seen!) to serve a D800E... the result is something you have to explain after all. So I took the time, went to http://www.dpreview.com/reviews/sigmasd1/19 and got both RAW-Files, from the Nikon D800E (http://movies.dpreview.com.s3.amazonaws.com/nikon_d800e/DSC_0087.NEF.zip) and from the SD1M (http://movies.dpreview.com.s3.amazonaws.com/sigma_sd1m/SDIM6084.X3F.zip).

Your misunderstanding. Every bayer pixel may have only one color, but regardless of color, every pixel receives "light". This is why the spatial resolution of a bayer sensor is so high, and why a D800 is capable of resolving so much detail. If you convert a bayer sensor's data to monochrome, you effectively have just the full detail luminance.

I take you literally, ok? I converted the NikonFile with CaptureOne7 to a stock b/w TIFF and the SigmaFile with SigmaPhotoPro5.5 to a b/w TIFF, too. So, here are the results (as png, to loose no pixelinformation):

NikonD800E:

Sigma SD1:

Sigma SD1, (normal) resized to fit the Nikonsize:

There are no tricks, no JPG Artefacts, no Color, no catch. You can repeat this by your own. Now, if you speak scientifically (as you apparently like), your theory has to get prooved. One counter evidence prooves a theory wrong, you know... this is my try. Explain the results as we speak from a 15MP against a 38MP. In my humble opinion the Sigma clearly outperforms the Nikon, and this is not just a pixelpeeping Testchart, this is my daily experience. I don't speak about the disadvantages (AF, HighISO, Accu...), they are all clear and bespoken.

 

[CarlTN]

Sure. As I've said, I have nothing against the concept, at all.

I truly, honestly believe that does Foveon a disservice. Not everything is about megapixel count.

Sigma should be marketing their DP series of cameras on the STRENGTHS of Foveon, instead of fabricating fanciful "megapixel equivalency" numbers and the like. They are undermining Foveon that way, when it IS such amazing technology.

If you were being honest here, you would own one yourself. You obviously are trying to have it both ways, trying to appear unbiased. You frankly have everything against this concept, when it comes to this manufacturer. Admit it, you don't like Sigma as a company, you would not buy any of their lenses or cameras. But The difference between you and me is, I've owned a foveon camera, the one with the sensor you deride most (and I currently own 2 Sigma lenses at the moment). It simply had more resolution than its native 4.6 MP dimensions...I'm sorry but it just did. You can rely on math all you like, but the proof is in the using, and viewing. To say that it only had 4.6 MP of resolution is utter nonsense. Plenty of reviews have backed me up on this.

As for the Quattro sensor, I have no idea why it has fewer photodiodes for the other color channels...but frankly, if they are making the camera produce a 39 MP jpeg, then logic would dictate that it is resolving at least somewhat more than 10 MP.

With a bayer array, you don't have 18 MP of all three colors of photodiode in your 7D. You have far less than that. And yet you're happy with the results you get.

Again, the proof is in the using, and the images, and less so the math. Math can be used to predict things like a rise of 10 feet in sea level over the next 20 years due to that nasty old capitalism, but how accurate, honest, and complete is that math?

 

[Sporgon]

Sure. As I've said, I have nothing against the concept, at all.

I truly, honestly believe that does Foveon a disservice. Not everything is about megapixel count.

Sigma should be marketing their DP series of cameras on the STRENGTHS of Foveon, instead of fabricating fanciful "megapixel equivalency" numbers and the like. They are undermining Foveon that way, when it IS such amazing technology.

If you were being honest here, you would own one yourself. You obviously are trying to have it both ways, trying to appear unbiased. You frankly have everything against this concept, when it comes to this manufacturer. Admit it, you don't like Sigma as a company, you would not buy any of their lenses or cameras. But The difference between you and me is, I've owned a foveon camera, the one with the sensor you deride most (and I currently own 2 Sigma lenses at the moment). It simply had more resolution than its native 4.6 MP dimensions...I'm sorry but it just did. You can rely on math all you like, but the proof is in the using, and viewing. To say that it only had 4.6 MP of resolution is utter nonsense. Plenty of reviews have backed me up on this.

As for the Quattro sensor, I have no idea why it has fewer photodiodes for the other color channels...but frankly, if they are making the camera produce a 39 MP jpeg, then logic would dictate that it is resolving at least somewhat more than 10 MP.

With a bayer array, you don't have 18 MP of all three colors of photodiode in your 7D. You have far less than that. And yet you're happy with the results you get.

Again, the proof is in the using, and the images, and less so the math. Math can be used to predict things like a rise of 10 feet in sea level over the next 20 years due to that nasty old capitalism, but how accurate, honest, and complete is that math?

Carl: shouldn't you be in bed at this time ?

 

[CarlTN]

Sure. As I've said, I have nothing against the concept, at all.

I truly, honestly believe that does Foveon a disservice. Not everything is about megapixel count.

Sigma should be marketing their DP series of cameras on the STRENGTHS of Foveon, instead of fabricating fanciful "megapixel equivalency" numbers and the like. They are undermining Foveon that way, when it IS such amazing technology.

If you were being honest here, you would own one yourself. You obviously are trying to have it both ways, trying to appear unbiased. You frankly have everything against this concept, when it comes to this manufacturer. Admit it, you don't like Sigma as a company, you would not buy any of their lenses or cameras. But The difference between you and me is, I've owned a foveon camera, the one with the sensor you deride most (and I currently own 2 Sigma lenses at the moment). It simply had more resolution than its native 4.6 MP dimensions...I'm sorry but it just did. You can rely on math all you like, but the proof is in the using, and viewing. To say that it only had 4.6 MP of resolution is utter nonsense. Plenty of reviews have backed me up on this.

As for the Quattro sensor, I have no idea why it has fewer photodiodes for the other color channels...but frankly, if they are making the camera produce a 39 MP jpeg, then logic would dictate that it is resolving at least somewhat more than 10 MP.

With a bayer array, you don't have 18 MP of all three colors of photodiode in your 7D. You have far less than that. And yet you're happy with the results you get.

Again, the proof is in the using, and the images, and less so the math. Math can be used to predict things like a rise of 10 feet in sea level over the next 20 years due to that nasty old capitalism, but how accurate, honest, and complete is that math?

Carl: shouldn't you be in bed at this time ?

I'm a night owl, I stay up late to take long exposure pictures of owls farting, hoping to see a rainbow by starlight... !! I actually need to move my hours a bit earlier, but I will still be awake until about this time, for the immediate future anyway.

What time is it in the world? Where you are? I assume you're in...ahh yes Yorkshire, how could I forget? Do you know the Top Gear lads? I'd love to watch them film someday!

 

[Sporgon]

;D

You seem to have been posting throughout the night ! I'm in England, it's 10 am here, a much more civilised time for posting