# Canon's Rumored 75mp Camera To Have a Non Bayer Multilevel Sensor?



## Canon Rumors Guy (Jul 23, 2013)

```
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<p><strong>Non Bayer Multilevel Sensor

</strong>[<a href="http://www.northlight-images.co.uk/cameras/Canon_1D_Xs.html" target="_blank">NL</a>] has been told that the <a href="http://www.canonrumors.com/2013/07/canon-testing-a-75-megapixel-eos-1-body-cr1/" target="_blank">rumored 75mp image sensor</a> Canon is testing is a “totally usable photosite count” and is a non bayer multilevel sensor. This patent for such technology appeared back in May of 2013.</p>
<p><strong>Source: [<a href="http://www.northlight-images.co.uk/cameras/Canon_1D_Xs.html" target="_blank">NL</a>]</strong></p>
<p><strong><span style="color: #ff0000;">c</span>r</strong></p>
```


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## Drizzt321 (Jul 23, 2013)

So something sorta like the Foveon X3 sensor? Or are they doing some other kind of tricks?


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## clicstudio (Jul 23, 2013)

Finally someone gets the idea of multi sensors...one for highlights and one for shadows or even a third one for mid tones...
Instant Dynamic Range heaven!
I can't wait for a camera that sees what my eyes see... 
Canon has to beat everyone else.
Progress in technology has been made with the dual pixel AF on the 70D. 
multiple sensors is the way to go. 
200 years later cameras haven't changed much, only in the past 15 years.
I can't wait for the future!


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## neuroanatomist (Jul 23, 2013)

Canon Rumors said:


> “totally usable photosite count”



Which means the "75 MP" sensor is really a 25 MP sensor in terms of spatial resolution.


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## rs (Jul 23, 2013)

clicstudio said:


> Finally someone gets the idea of multi sensors...one for highlights and one for shadows or even a third one for mid tones...
> Instant Dynamic Range heaven!
> I can't wait for a camera that sees what my eyes see...
> Canon has to beat everyone else.
> ...


More likely to be foveon-like than high DR, so a genuine 25MP output. This looks like the patent which is mentioned from May 2013:

http://www.canonrumors.com/2013/05/patent-canon-foveon-sensor/


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## Drizzt321 (Jul 23, 2013)

clicstudio said:


> Finally someone gets the idea of multi sensors...one for highlights and one for shadows or even a third one for mid tones...
> Instant Dynamic Range heaven!
> I can't wait for a camera that sees what my eyes see...
> Canon has to beat everyone else.
> ...



Doesn't necessarily mean that, it might be stacked photosites to detect R, G, and B separately, but specially the same so that you get the true color at that pixel, instead of having to interpolate by de-bayering. Sorta like what they do with 3CCD cameras, except stack the photosites so you have a single chip.


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## Snaps (Jul 23, 2013)

clicstudio said:


> Finally someone gets the idea of multi sensors...one for highlights and one for shadows or even a third one for mid tones...
> Instant Dynamic Range heaven!
> I can't wait for a camera that sees what my eyes see...
> Canon has to beat everyone else.
> ...



So if I'm undestanding this correctly, it's a sensor with 75 million diodes which are split up into three parts for the highlights, midtones, and shadows?


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## neuroanatomist (Jul 23, 2013)

Snaps said:


> clicstudio said:
> 
> 
> > Finally someone gets the idea of multi sensors...one for highlights and one for shadows or even a third one for mid tones...
> ...



You're correctly understanding clicstudio's desire, but not the patent on which this rumor is based. That patent is for a Foveon-like sensor, where the three layers (different depths in the silicon wafer) are detecting blue/green/red.


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## bchernicoff (Jul 23, 2013)

neuroanatomist said:


> You're correctly understanding clicstudio's desire, but not the patent on which this rumor is based. That patent is for a Foveon-like sensor, where the three layers (different depths in the silicon wafer) are detecting blue/green/red.



Isn't Sigma's 46 megaphotosite sensor supposed to have the equivalent spatial resolution as a 30mp bayer sensor? I wonder how a 75mps sensor from Canon would compare under ideal circumstances with one of their bayer sensors.


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## Snaps (Jul 23, 2013)

neuroanatomist said:


> Snaps said:
> 
> 
> > clicstudio said:
> ...



Gotcha! I just did a quick read on the Foveon X3 sensor. Quite interesting tech I must say, although the Sigma Foveon cameras seem to fall short of what's possible with those sensors.


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## Mt Spokane Photography (Jul 23, 2013)

The reference patent is for a Foveon type sensor. It proposes to overcome the light loss in the deepest layer of photo sites by making the photo site three dimensional and resonant at the wavelength of the color (apparently red). By making the photosite resonant, the sensitivity to that color of light is greatly increased, which makes tiny photosites more practical.

This is one of the big drawbacks with existing Foevon Sensors, they have poor light sensitivity due to light loss or diffusion of light traveling to the lower layer. It gets very bad as photo sites get smaller.

Its very likely that the sensor is being tested, but that's normal, you have to test to verify that a new technology works and that its practical. The big question is still whether it overcomes the inherent weaknesses of a Foveon type sensor. They have issues with color accuracy, high ISO noise, and reduced DR. We want more of all those, so it would be a big breakthrough if that actually happened.


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## bchernicoff (Jul 23, 2013)

Mt Spokane Photography said:


> Its very likely that the sensor is being tested, but that's normal, you have to test to verify that a new technology works and that its practical. The big question is still whether it overcomes the inherent weaknesses of a Foveon type sensor. They have issues with color accuracy, high ISO noise, and reduced DR. We want more of all those, so it would be a big breakthrough if that actually happened.



It sure would be neat if Canon released info on their sensor desigm/testing/manufacturing lifecycle on the Canon Museum site. It would be interesting to read about their "process". It might also give us some insight into how long after a "being tested" rumor surfaces we can expect a new product release.

UPDATE: it seems like it sorta exists, but is terrible(cheesy/marketing BS): http://www.canon.com/camera-museum/design/making/index.html


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## neuroanatomist (Jul 23, 2013)

bchernicoff said:


> neuroanatomist said:
> 
> 
> > You're correctly understanding clicstudio's desire, but not the patent on which this rumor is based. That patent is for a Foveon-like sensor, where the three layers (different depths in the silicon wafer) are detecting blue/green/red.
> ...



A Foveon-type "75 MP" filter is giving you a spatial resolution based on 25 MP (because they're separately counting three stacked photosites that are in the same physical location on the image sensor. But it's not a simple relationship, because it depends on the strength of the AA filter of a sensor with a Bayer CFA. So a 'regular' 25 MP sensor (with a CFA and an AA filter) isn't giving you 25 MP of real spatial resolution, but something less.


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## Mt Spokane Photography (Jul 23, 2013)

bchernicoff said:


> Mt Spokane Photography said:
> 
> 
> > Its very likely that the sensor is being tested, but that's normal, you have to test to verify that a new technology works and that its practical. The big question is still whether it overcomes the inherent weaknesses of a Foveon type sensor. They have issues with color accuracy, high ISO noise, and reduced DR. We want more of all those, so it would be a big breakthrough if that actually happened.
> ...


 
Thanks for the link, I'd forgotten where I'd seen it.

The big issue is that you have to kiss a lot of frogs to find that prince. 

I doubt if one in a hundred test designs makes it to production, but they need to be done to identify weaknesses that can't be discovered in a lab environment, and that allows for a chance to fix them, or go to plan B.

Canon now has their robotic manufacturing targets in place, so I'd expect the capability to be robotically assembled is a new factor in designs. I'm suspecting that every sub assembly will have to be redesigned, since so much is now hand assembled, and its difficult. Even more modular design and throw away assemblies that can't be repaired. I was thinking that their new packaging for sensors on the SL1 may be part of that, they needed a smaller package, so why not kill two birds with one stone?


http://www.robots-dreams.com/2012/05/canon-building-new-robotic-factories-in-japan.html


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## bchernicoff (Jul 23, 2013)

neuroanatomist said:


> A Foveon-type "75 MP" filter is giving you a spatial resolution based on 25 MP (because they're separately counting three stacked photosites that are in the same physical location on the image sensor. But it's not a simple relationship, because it depends on the strength of the AA filter of a sensor with a Bayer CFA. So a 'regular' 25 MP sensor (with a CFA and an AA filter) isn't giving you 25 MP of real spatial resolution, but something less.



Maybe I was using the term spatial resolution wrong. I understand that an AA filter and the debayering algorithm reduce actual resolved detail compared to an ideal 25mp sensor with no color or AA filters at all. The problem is that we have gotten used to relating resolved detail to mp count with today's sensors. What I am wondering is what current-technology equivalent mp value would a 75 megaphotosite sensor maps to in terms of resolved detail? The Sigma cameras certainly resolve more detail than a camera with a traditional 15mp sensor does (like the 50D). I doubt it's comparable to 30mp as they claim, but it's surely better then 15mp.


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## neuroanatomist (Jul 23, 2013)

bchernicoff said:


> What I am wondering is what current-technology equivalent mp value would a 75 megaphotosite sensor maps to in terms of resolved detail?



No idea. How about we say 37 MP? Not because it's close to half of 75, but because it's one more than 36.


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## comsense (Jul 23, 2013)

neuroanatomist said:


> Canon Rumors said:
> 
> 
> > “totally usable photosite count”
> ...


Its true only in terms of sensor architecture. In terms of image spacial resolution situation is far more complicated. While bayer and anti-aliasing filter leads to image spacial resolution loss in bayer sensors, its scattering of red photons in foveon. The reality is somewhere halfway for each. At the least, 25 MP foveon is going to be far superior to 25 MP bayer sensor in terms of spatial resolution of image.


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## RLPhoto (Jul 23, 2013)

If there is a company to get this style of sensor correct and make it well, it's canon.


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## Pi (Jul 23, 2013)

bchernicoff said:


> What I am wondering is what current-technology equivalent mp value would a 75 megaphotosite sensor maps to in terms of resolved detail?



Hard to say because there is no single measure or resolution and therefore, no way to compare different sensors based on a single number.


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## bchernicoff (Jul 23, 2013)

Pi said:


> bchernicoff said:
> 
> 
> > What I am wondering is what current-technology equivalent mp value would a 75 megaphotosite sensor maps to in terms of resolved detail?
> ...



I think line pairs per millimeter is pretty standard and directly comparable.


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## Drizzt321 (Jul 23, 2013)

bchernicoff said:


> Pi said:
> 
> 
> > bchernicoff said:
> ...



Except the problem is most reviewers don't (or can't) compare using the exact same lens, much less the exact same physical lens (due to different lens mounts).


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## Lawliet (Jul 23, 2013)

bchernicoff said:


> What I am wondering is what current-technology equivalent mp value would a 75 megaphotosite sensor maps to in terms of resolved detail?



Theoretically thats dependent on what you shoot - gray gets picked up by all sites and you get the full resolution. Pure colored red fabrics for example otoh are a nightmare, only a quarter of the sites and repeating patterns that can cause artifacts.
Practically: Even at ISO100 whether a 5D3 or D800 give you more usable resolution depends on about everything but the sensor... 
25MP RGB and a sync speed that avoids motion blur and cuts ambient light enough to avoid narrow apertures/shortens flash duration plus a Canons current glass/AF? Sounds great!


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## neuroanatomist (Jul 23, 2013)

Pi said:


> ... no way to compare different sensors based on a single number.



Shhhhhh....whatever you do, don't tell DxOMark! :


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## Drizzt321 (Jul 23, 2013)

neuroanatomist said:


> Pi said:
> 
> 
> > ... no way to compare different sensors based on a single number.
> ...



I knew you couldn't resist! I was just waiting to see what you would post.


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## Pi (Jul 23, 2013)

neuroanatomist said:


> Pi said:
> 
> 
> > ... no way to compare different sensors based on a single number.
> ...



I will not, I promise!


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## Pi (Jul 23, 2013)

bchernicoff said:


> Pi said:
> 
> 
> > bchernicoff said:
> ...



At what loss of contrast (MTF)? Measured in what way: slanted edge or something else? If so, how slanted is the slanted edge? Demosaiced or not? At what channel (color)? Vertical, horizontal resolution, or something else?

DXO used to publish much more "diversified" data. The numbers/curves depended a lot on the color, for example, not to mention on the MTF value.


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## bchernicoff (Jul 23, 2013)

Pi said:


> At what loss of contrast (MTF)? Measured in what way: slanted edge or something else? If so, how slanted is the slanted edge? Demosaiced or not? At what channel (color)? Vertical, horizontal resolution, or something else?
> 
> DXO used to publish much more "diversified" data. The numbers/curves depended a lot on the color, for example, not to mention on the MTF value.



I think MTF 50 is fairly standard. As to what color channel, the final demosaiced RGB image of a black and white subject is fine. Color artifacts from demosaicing affects contrast, so that is taken into account.

I think you are WAY over thinking what I was asking. I will rephrase. "Asking semi-rhetorically, I wonder what megapixel class of bayer filter camera this new camera will compare to in terms of line pairs per millimeter at MTF 50. 30-ish? 40-ish? 50-ish?"


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## unfocused (Jul 23, 2013)

This is fun to speculate about, but honestly, if past performance is any indicator of future accuracy, I wouldn't be putting any money on predictions from Northlight Images.


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## Lawliet (Jul 23, 2013)

bchernicoff said:


> I wonder what megapixel class of bayer filter camera this new camera will compare to in terms of line pairs per millimeter at MTF 50. 30-ish? 40-ish? 50-ish?"


For "close enough" something in the D800-Range, about 35MP or so would give you a stable and close approximation. For an accurate solution your looking more in the PhaseOne IQ bracket.


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## Pi (Jul 23, 2013)

bchernicoff said:


> Pi said:
> 
> 
> > At what loss of contrast (MTF)? Measured in what way: slanted edge or something else? If so, how slanted is the slanted edge? Demosaiced or not? At what channel (color)? Vertical, horizontal resolution, or something else?
> ...



Until recently, DXO considered MTF 10 to be "the standard", measured on the G channel, at 5 degrees slope, not demosaiced. So you see that their definition of what was standard differed a lot from yours. As a result, there was very clear jump in resolution, from, say 12m to 15mp, then to 18mp, same lens. Then they decided to change the metric. Now, a 36mp sensor does not look that different from a 21/22mp one. The new (secret) metric seems to emphasize more higher MTF values, and might react differently to, say, aliasing; or the angle.

I am afraid that you are the one oversimplifying it.


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## dtaylor (Jul 23, 2013)

bchernicoff said:


> Maybe I was using the term spatial resolution wrong. I understand that an AA filter and the debayering algorithm reduce actual resolved detail compared to an ideal 25mp sensor with no color or AA filters at all. The problem is that we have gotten used to relating resolved detail to mp count with today's sensors.



That is indeed the problem. Not trying to pick on anyone here because everyone does it, but it's incorrect to say that a sensor with X MP yields less then X MP. MP is nothing more then the output of the photo sites on the sensor. It's not actually a statement of the sensor's resolution, only a statement of the sensor's physical dimensions which are generally a decent proxy for resolution.



> What I am wondering is what current-technology equivalent mp value would a 75 megaphotosite sensor maps to in terms of resolved detail? The Sigma cameras certainly resolve more detail than a camera with a traditional 15mp sensor does (like the 50D). I doubt it's comparable to 30mp as they claim, but it's surely better then 15mp.



It's going to vary with target detail color. It's going to vary at different MTF points. And it's going to vary based on RAW converter and whether or not you sharpen the Bayer file and by how much.

That said, Imaging Resource got 2,200 LPH of "strong detail" (MTF50?) out of the Sigma DP1 Merrill. They said complete extinction (MTF10?) did not occur even at 4,000 LPH. By comparison on their test, the 50D hit 1,800 / 2,600. (I put a question mark by the MTF values because I'm not sure if those are the values IR actually uses.) So for strong detail this would suggest the Foveon is 20% better, but for extinction resolution it would suggest over 50% better.

It should be noted that later versions of ACR yield higher extinction resolution numbers. Redoing the test with the 50D and the latest version of ACR may yield higher numbers, though there is clearly some advantage to Foveon in any case.

Of course, the Foveon advantage is nothing like the 14 stop DR advantage of the Nikon D800. If you haven't already done so, burn all your other equipment in a fire and purchase the D800 ;D


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## Mt Spokane Photography (Jul 24, 2013)

unfocused said:


> This is fun to speculate about, but honestly, if past performance is any indicator of future accuracy, I wouldn't be putting any money on predictions from Northlight Images.


 
They, like CR report rumors from sources that have been right in the past, as well as ones from new sources. The rumor sites protect their sources very carefully, some of them do have inside information.

At any given time, lots of different prototypes of cameras and lenses are being tested by Canon employees. Once a prototype is given to photographers to test, then the odds of it being eventually released rise, but are still not high.


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## neuroanatomist (Jul 24, 2013)

Pi said:


> I am afraid that you are the one oversimplifying it.



Perhaps not eventually. Certainly for now, it's speculation and WAGs. But should Canon actually come out with a 75 MP (25 MP) Foveon-type sensor, we could measure LP/mm and/or SQF directly (i.e., with Imatest), and compare that to Bayer sensors with the exact same lens. Or maybe not - I'm assuming data from existing FF sensors can be plotted and extrapolated to simulate higher MP sensors that don't exist, but I haven't actually tried it.


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## CarlTN (Jul 24, 2013)

dtaylor said:


> bchernicoff said:
> 
> 
> > Maybe I was using the term spatial resolution wrong. I understand that an AA filter and the debayering algorithm reduce actual resolved detail compared to an ideal 25mp sensor with no color or AA filters at all. The problem is that we have gotten used to relating resolved detail to mp count with today's sensors.
> ...



That last comment is humorous, thank you. Especially since you're saying 14 stop _advantage_, as in the notorious proponents of the D800's sensor, are so vigorous in their zealousness, that it is almost as if they're saying there is an _additional _ 14 stops advantage over Canon counterparts. 13+14= 27 stops !!

I hadn't considered that the 75mp sensor could be a "foveon" type sensor. Does Sigma not hold the patent on the technique? Or can Canon develop such a sensor without infringing anything, if it never goes into production? I recall the rumor about Canon's possible development of one.

I've owned both the 50D and a Sigma DP2 (4.6 MP). I have no doubt the Merrill sensor can out-resolve the 50D, as you just pointed out in the test results above. The generation 1 sensor came quasi-close to the 50D's resolution. I used ACR 6.4 to develop the RAW files. It was about 12 to 14mp before things got slightly soft, but I scaled one file up to 80 MP, and to me it might be usable for a print at 240 dpi, if you didn't view it closer than 30 inches or so. Of course there were color anomalies, but they weren't obvious. 

If any of you would like me to attempt to post that 80 MP jpeg, let me know. (Or if you would like me to scale it to a lesser extreme like 40 MP). It's an infinity focus shot done from atop a local mountain. Compositionally it's not mind blowing...I just snapped it while I was visiting someone.


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## Lawliet (Jul 24, 2013)

CarlTN said:


> Does Sigma not hold the patent on the technique?


That would depend on what exactly was patented. The more you go into detail the easier its to do the same thing just different enough, the other way around you have to deal with prior art or significance.
Patents protect someones commercial interests, in research you still can use everything in there - one reason some inventions aren't patented: you gamble on the actual secret staying a secret instead of telling them exactly what they aren't allowed to do...for a while.


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## bchernicoff (Jul 24, 2013)

dtaylor said:


> That said, Imaging Resource got 2,200 LPH of "strong detail" (MTF50?) out of the Sigma DP1 Merrill. They said complete extinction (MTF10?) did not occur even at 4,000 LPH. By comparison on their test, the 50D hit 1,800 / 2,600. (I put a question mark by the MTF values because I'm not sure if those are the values IR actually uses.) So for strong detail this would suggest the Foveon is 20% better, but for extinction resolution it would suggest over 50% better.
> 
> It should be noted that later versions of ACR yield higher extinction resolution numbers. Redoing the test with the 50D and the latest version of ACR may yield higher numbers, though there is clearly some advantage to Foveon in any case.



This is very interesting and why I asked my question in the first place. Even if this camera never comes to market it would be _very_ interesting to see what the advantages and disadvantages were. 

Warning, somewhat off topic:
I know it will never happen, but it would be so cool to see digital bodies become more film like. I'm talking about interchangeable sensors. Obviously, sensors work in concert with other integrated circuits so it would have to be an interchangeable sensor/processor board with a common bus to work with various bodies. But how neat would it be if you could have a light compact body (including mirror assembly, af, light metering, lcd, etc) as well as something 1DX style for high fps, weather sealing, etc. AND then have different sensor cards that worked with either body to choose from based on what you were shooting... a large megapixel sensor for landscapes and studio work or something with big photosites for low-light work. New sensors could bring new imaging features while new bodies would bring new AF, metering, wifi, gps, etc features. 

Suppose this were how it worked today. Imagine this scenario: You have the choice of a 5D Mk II, 5D Mk III, 6D, 1DsMk III, or 1D X body independent of your choice among those sensors. Imagine you have bought into the Canon system in 2008 with 5D Mk II body and its 21.1mp sensor. Now the 5D Mk III line launches as body only, sensor only, or as a kit. You could choose to only upgrade the body and use the existing sensor to gain improved AF, construction, light metering with the trade off being you would still be limited to 3.9fps (I realize this sensor did 6fps in the 1Ds Mk3, but even in my imagined scenario Canon software locks some features out of non 1D bodies). I think a lot of people who upgraded from 5D Mk II to III would choose this path to save some money. Now imagine this hypothetical 75megaphotosite sensor comes out and it's S___ past ISO 400. If that's the actual case, Canon may well decide it's not ready to go on the market, that it couldn't really survive as a whole product. However, it might succeed just as a sensor card upgrade.

I DO realize there are a ton of challenges with what I am suggesting but this is not pie in the sky stuff. Honestly, the biggest challenge might be how it would shake up the pricing/shopping paradigm we currently have. Difficulty forecasting how many of each component they would sell and calculating a break even price on their development costs, etc... that sort of thing.


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## Lawliet (Jul 24, 2013)

bchernicoff said:


> I know it will never happen, but it would be so cool to see digital bodies become more film like. I'm talking about interchangeable sensors. Obviously, sensors work in concert with other integrated circuits so it would have to be an interchangeable sensor/processor board with a common bus to work with various bodies.



Actually you can buy just that, even trade in outdated sensors at a vastly more attractive rate then their retail cost. 
Thats how things work in 645, even rather cross brand friendly. But try to explain that to the average store chain customer who is already uneasy with the interchangeable lens paradigm.


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## Pi (Jul 24, 2013)

neuroanatomist said:


> Pi said:
> 
> 
> > I am afraid that you are the one oversimplifying it.
> ...



Perhaps you can then tell me which is sharper: the 5D or the 60D? I have seen a comparison on dpreview which can support either conclusion, depending what you are looking at (and it is not AF or DOF problem).


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## Pi (Jul 24, 2013)

dtaylor said:


> That said, Imaging Resource got 2,200 LPH of "strong detail" (MTF50?) out of the Sigma DP1 Merrill. They said complete extinction (MTF10?) did not occur even at 4,000 LPH.


What they actually measure is aliasing:


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## M.ST (Jul 24, 2013)

You are on the right track. The big megapixel sensor IS a non Bayer pattern sensor like the Sigma sensor. Every pixel can have every color and IS sensible for the RGB Colors.


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## Drizzt321 (Jul 24, 2013)

Lawliet said:


> bchernicoff said:
> 
> 
> > I know it will never happen, but it would be so cool to see digital bodies become more film like. I'm talking about interchangeable sensors. Obviously, sensors work in concert with other integrated circuits so it would have to be an interchangeable sensor/processor board with a common bus to work with various bodies.
> ...



Wasn't there some announcement a while ago that had a lens+sensor module that was interchangeable? The way they were talking you could put in a FF with a wide/super-wide or with a very fast lens for landscape or low light, and then a moderate focal length with a very small sensor for super-telephoto at much less than a FF + 400/500/600mm lens. Or was it just an idea announcement and never got any attraction or went anywhere?


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## dtaylor (Jul 24, 2013)

Pi said:


> What they actually measure is aliasing:



The pattern is resolved. It's not perfect and there is aliasing, but it's there.


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## Pi (Jul 24, 2013)

dtaylor said:


> Pi said:
> 
> 
> > What they actually measure is aliasing:
> ...



What if there is no pattern but fine detail, like in landscape photos? 

Look at the resolution chart. It is an aliasing/moire fest, you can get dizzy just by looking at it.

EDIT: Here: http://www.sigma-sd.com/SD1/sample-photo/img/SDIM8118AA.jpg is an extreme (IMO) case of aliasing, taken directly from the Sigma webpage. Look the highlights in the hair, on (our) right of the chin and the neck. Is that resolution? How many "Bayer mp" of it?


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## neuroanatomist (Jul 24, 2013)

Pi said:


> neuroanatomist said:
> 
> 
> > Pi said:
> ...



That's why I stated 'existing FF sensors' - I'm takling about comparing resolution values from the same size sensor.


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## dgatwood (Jul 24, 2013)

neuroanatomist said:


> ... a 75 MP (25 MP) Foveon-type sensor ...



I find that wording curious. I believe the original rumor said 75 million photosites, not 75 MP. A photosite is, by definition, a pit on the surface of the chip, not a subpixel. Thus, you would not divide by three, but rather optionally multiply by three to get an arguably disingenuous megapixel count.


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## neuroanatomist (Jul 24, 2013)

dgatwood said:


> neuroanatomist said:
> 
> 
> > ... a 75 MP (25 MP) Foveon-type sensor ...
> ...



True. I was merely echoing the title of the topic, "Canon's Rumored *75mp* Camera To Have a Non Bayer Multilevel Sensor?"


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## Pi (Jul 24, 2013)

neuroanatomist said:


> Pi said:
> 
> 
> > neuroanatomist said:
> ...



I tried that once but I do not keep the result. If I remember well, each decent lens can at least double or triple its resolution with a super high mp sensor, in the (old) DXO units, for example. It was not just interpolation, it was based on a approximate formula how lens and sensor resolution act together. When I have more time, I will do it more carefully, with more data, if I can dig up the old DXO MTF tables. 

Visual examples have been posted here, I believe. Pentax Q can do wonders with an EF lens. I do not have the time now to compute its pixel density, but it is certainly more than 75mp on FF.


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## jrista (Jul 24, 2013)

Pi said:


> neuroanatomist said:
> 
> 
> > Pi said:
> ...



Looks like the Pentax Q has 1.54µm pixels in a 1/2.3" sensor (6.17mm x 4.55mm). A 36x24mm sensor with the same pixel pitch would have around 23380x15600 pixels, which comes out to 365mp.


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## CarlTN (Aug 1, 2013)

Lawliet said:


> CarlTN said:
> 
> 
> > Does Sigma not hold the patent on the technique?
> ...



Interesting point.


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## CarlTN (Aug 1, 2013)

Pi said:


> dtaylor said:
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> > Pi said:
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I'm not seeing where the aliasing in the hair is. In the part that goes out of focus behind the focal plane? I guess there is some. It's a remarkably sharp picture, though. She should have trimmed her nose hairs...!


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## AlanF (Aug 1, 2013)

[/quote]

Looks like the Pentax Q has 1.54µm pixels in a 1/2.3" sensor (6.17mm x 4.55mm). A 36x24mm sensor with the same pixel pitch would have around 23380x15600 pixels, which comes out to 365mp.
[/quote]

The Powershot SX50 has basically the same size sensor (6.16mm x 4.62mm) with 1.54 µM pixels. Stitch 5x5 together to get an FF with about a 400MB file size for each RAW image.


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## Pi (Aug 4, 2013)

CarlTN said:


> Pi said:
> 
> 
> > I'm not seeing where the aliasing in the hair is. In the part that goes out of focus behind the focal plane? I guess there is some. It's a remarkably sharp picture, though. She should have trimmed her nose hairs...!



What you consider a remarkably sharp (hair) is a classical example of aliasing, with blown pixels, etc.


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## jrista (Aug 4, 2013)

Pi said:


> CarlTN said:
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> > Pi said:
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Hmm, I see aliasing if I view the image at the scaled down size in my browser. When I click it to view at 100% size, that horrible aliasing disappears. The photo IS remarkably sharp, and there is only noticeable aliasing in a few areas where the highlights on each strand blow out. I would also point out that its "clean" aliasing...not the kind of color moire you get with a bayer sensor.

If you are trying to use that photo as an example of how bad layered sensor designs are...then at their worst, they are pretty darn good! I'm now completely sold on the approach. I can't wait to see a 3-layer sensor from Canon!


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## Pi (Aug 4, 2013)

jrista said:


> Pi said:
> 
> 
> > What you consider a remarkably sharp (hair) is a classical example of aliasing, with blown pixels, etc.
> ...




Here is what I am talking about:







As if she suffers from dandruff. Looks horrible to me.



> If you are trying to use that photo as an example of how bad layered sensor designs are...then at their worst, they are pretty darn good! I'm now completely sold on the approach. I can't wait to see a 3-layer sensor from Canon!



My remark has nothing to do with layered sensors. They need AA filters (at the current pixel densities) as well, just weaker ones.


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## jrista (Aug 5, 2013)

Pi said:


> jrista said:
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> > Pi said:
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Hmm, I guess I wouldn't call what I see in that crop moire or aliasing. The edges of the hairs outside of the specular highlights are quite smooth...you can BARELY see some jagged edges in a couple of them, but for the most part, they appear to be fairly crisp, clean, and smooth. I think the issue there is just the nature of the lighting and the nature of her hair. I've seen similar issues with the D800 (non-E version WITH the AA filter). I would be willing to bet that some softening of the light would reduce the harshness of those highlights, and eliminate what you are calling aliasing.


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## Pi (Aug 5, 2013)

jrista said:


> Hmm, I guess I wouldn't call what I see in that crop moire or aliasing. The edges of the hairs outside of the specular highlights are quite smooth...you can BARELY see some jagged edges in a couple of them, but for the most part, they appear to be fairly crisp, clean, and smooth. I think the issue there is just the nature of the lighting and the nature of her hair. I've seen similar issues with the D800 (non-E version WITH the AA filter). I would be willing to bet that some softening of the light would reduce the harshness of those highlights, and eliminate what you are calling aliasing.



It is not "what I call aliasing", _it is_ aliasing. The latter is not just moire of jagged lines. Extreme contrast between pixels is an artifact, always. Or maybe the model just needs to take a shower, I do not know.  In any case, what I see looks awful. 

EDIT: here is a computer generated aliased image, with no regular patterns. Bad hair or ... aliasing? 






Source: http://www.howtogeek.com/73704/what-is-anti-aliasing-and-how-does-it-affect-my-photos-and-images/


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## jrista (Aug 5, 2013)

Pi said:


> jrista said:
> 
> 
> > Hmm, I guess I wouldn't call what I see in that crop moire or aliasing. The edges of the hairs outside of the specular highlights are quite smooth...you can BARELY see some jagged edges in a couple of them, but for the most part, they appear to be fairly crisp, clean, and smooth. I think the issue there is just the nature of the lighting and the nature of her hair. I've seen similar issues with the D800 (non-E version WITH the AA filter). I would be willing to bet that some softening of the light would reduce the harshness of those highlights, and eliminate what you are calling aliasing.
> ...



Well, if we are going to get technical, technically speaking every pixel in an image is an alias of the real image the sensor resolved. Artifact or not, to me, the girls hair just looks crisp and sharp, maybe a bit oily or loaded with some kind of hair product, with some harsh specular highlights.

Comparing the results of a layered sensor without an AA filter to a bayer sensor with an AA filter, I think there is a definite sharpness *benefit *with the layered/no-AA approach, mostly offered by the fact that 100% of the image is being fully sampled at every photosite, vs. bayer which is sparsely sampled. If one finds it too sharp, there are a variety of ways that could be addressed....a mesh filter on the lens, post-process desharpening, etc. 

Maybe this is just me, but I could never complain about too much sharpness. I am far more likely to complain about to little sharpness, as you really can't fabricate additional real detail in post.


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## Pi (Aug 5, 2013)

jrista said:


> Well, if we are going to get technical, technically speaking every pixel in an image is an alias of the real image the sensor resolved.



Google "sampling theory". 



> Comparing the results of a layered sensor without an AA filter to a bayer sensor with an AA filter, I think there is a definite sharpness *benefit *with the layered/no-AA approach, mostly offered by the fact that 100% of the image is being fully sampled at every photosite, vs. bayer which is sparsely sampled.



As I said, this is not a layered vs. Bayer sensor discussion. 



> If one finds it too sharp, there are a variety of ways that could be addressed....a mesh filter on the lens, post-process desharpening, etc.



Why not an AA filter instead of a mesh filter? PP cannot remove effects of improper sampling. 



> Maybe this is just me, but I could never complain about too much sharpness. I am far more likely to complain about to little sharpness, as you really can't fabricate additional real detail in post.



It is not detail. So you actually prefer this:






to that:


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## jrista (Aug 5, 2013)

Well, I think your last comparison there is a bit unrealistic. You are comparing something on the order of 100x100 pixels to a photo with millions of pixels. I don't see the same thing (that rogue aliasing) in the original photo...its crisp and sharp, but not hideously aliased like your mock example. I've seen far worse examples of real-world aliasing and moire.

I'll see if I can find some examples of the D800 portraits I saw last year that were EXTREMELY sharp like that...and it seemed to be exactly what the photographer wanted. Sure, maybe its "aliased", but if that aliasing falls within the threshold of the photographers tolerance, I am not sure I would call it "incorrectly sampled".

I think at this point we are just debating personal preference, not any kind of real-world IQ-debilitating issue. Differing degrees of how sharp is sharp enough.

(CAVEAT: I just realized that I am looking at that photo on a MacBook 15" Retina. The pixel density may be changing how I perceive the photo. With this pixel density, it looks rather phenomenal...I'll admit it may look worse on a lower density screen. This screen is much closer to what a print would look like, and I would be quite happy with this kind of sharpness in a print.)


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## Pi (Aug 5, 2013)

jrista said:


> Well, I think your last comparison there is a bit unrealistic. You are comparing something on the order of 100x100 pixels to a photo with millions of pixels. I don't see the same thing (that rogue aliasing) in the original photo...its crisp and sharp, but not hideously aliased like your mock example. I've seen far worse examples of real-world aliasing and moire.



Actually, the Sigma photo is not less aliased, both compared at 100%. Think of this example as a crop of a wide angle shot with a lot of people there. Also, the Sigma photo looks unnatural even downsized a lot. Anyway, which image do you prefer?



> I'll see if I can find some examples of the D800 portraits I saw last year that were EXTREMELY sharp like that...and it seemed to be exactly what the photographer wanted. Sure, maybe its "aliased", but if that aliasing falls within the threshold of the photographers tolerance, I am not sure I would call it "incorrectly sampled".
> 
> I think at this point we are just debating personal preference, not any kind of real-world IQ-debilitating issue. Differing degrees of how sharp is sharp enough.



We are talking about sampling theory. Is is a personal preference whether you like aliased images or not but sampling theory is not a preference.


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## jrista (Aug 5, 2013)

Pi said:


> jrista said:
> 
> 
> > Well, I think your last comparison there is a bit unrealistic. You are comparing something on the order of 100x100 pixels to a photo with millions of pixels. I don't see the same thing (that rogue aliasing) in the original photo...its crisp and sharp, but not hideously aliased like your mock example. I've seen far worse examples of real-world aliasing and moire.
> ...



Just talking sampling theory, I guess I would prefer that frequencies below/around nyquist be removed or otherwise softened (most people hate the 7Ds AA filter, but personally I find it quite ideal for bird photography, it definitely avoids a lot of nasty color moire and other artifacts that are frequently caused by the overlap of birds feathers, without severely softening the results). I don't like moire in particular. I usually don't like jagged edges either, however I think whether it is "acceptable" often depends on the actual image (I do like crisp, sharp images, and the sharper they are out of the camera the less I have to boost sharpening (and therefor halos) in post). 

I don't really see any jagged edges in the original photo of the girl (however that may simply be a benefit of the Retina display...will have to check on my home computer in a little bit here to see what everyone else is seeing.)


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## jrista (Aug 6, 2013)

Here is one of the D800 (non-E) images I was talking about earlier (warning, the file is HUGE, and the server is slow):

http://www.bezergheanu.com/TestNikon/Test-Nikon-D800/i-BN6QTnD/0/O/LAN1776.jpg

Between the sharp strands of hair in this, and the sharp strands of hair in the SD1 shot, I personally don't notice any appreciable difference. I'm at home now, on my 30" CinemaDisplay...lower pixel density than the Retina, and I do notice aliasing a bit more in both photos...but I guess the extreme sharpness doesn't bother me as much as more pronounced jaggies that one might get with the D800E, or moire (color moire especially).

Here is the EXIF, just to be clear this is a D800, not a D800E, photo...so an AA filter was in place:

_Orientation of image: 1
File change date and time: 2012:03:25 19:15:54
*Image input equipment manufacturer: NIKON CORPORATION
Image input equipment model: NIKON D800*
Software used: Adobe Photoshop CS5 Windows
Copyright holder: 
Exposure time: 0.004
F number: 8
Exposure program: 1
ISO speed rating: 100
Shutter speed: 7.96578
Aperture: 6
Exposure bias: -0.333333
Maximum lens aperture: 1
Metering mode: 5
Light source: 4
Flash: 16
Lens focal length: 85
Sensing method: 2
Custom rendered: 0
Exposure mode: 1
White balance: 1
Digital zoom ratio: 1
Focal length in 35 mm film: 85
Scene capture type: 0
Gain control: 0
Contrast: 0
Saturation: 0
Sharpness: 2
Subject distance range: 0_

Even despite the AA filter, I would actually call the sampling of the sharp strands of hair worse than with the SD1. Where it lays along her shoulder, and a bit along the back left side, you can see what looks like stippling. That is an artifact that is absent from the SD1 photo.


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## Pi (Aug 6, 2013)

jrista said:


> Even despite the AA filter, I would actually call the sampling of the sharp strands of hair worse than with the SD1.



I find it much better. It also looks good downsized. The Sigma photo is a disaster, IMO. The Nikon is very good, with some faults.


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## jrista (Aug 6, 2013)

Pi said:


> jrista said:
> 
> 
> > Even despite the AA filter, I would actually call the sampling of the sharp strands of hair worse than with the SD1.
> ...



Well, like I said before. I think we are firmly within the realm of personal preference now, taking the debate out of the realm of sampling theory and into the realm of unwinnable or otherwise pointless argument!


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## CarlTN (Aug 6, 2013)

Pi said:


> CarlTN said:
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> > Pi said:
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That's a tad presumptive, you don't know what I consider sharp or not. You're just seeking argument, but then, so does Jrista. You two should get forum married...


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## Pi (Aug 6, 2013)

CarlTN said:


> That's a tad presumptive, you don't know what I consider sharp or not.



Aliasing does not exclude sharpness, it is just not a sharp image of the original, it is something else (some call it false detail). Add noise, for example, and it will get even sharper (it will increase the high frequency component). 

I never argued about what you, or somebody else, should like. I just call it what it is. Liking aliased images is perfectly legal in this country.


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## CarlTN (Aug 6, 2013)

Pi said:


> CarlTN said:
> 
> 
> > That's a tad presumptive, you don't know what I consider sharp or not.
> ...



I didn't say I liked aliases images, I said I couldn't see aliasing in the image. Obviously to you it sticks out, to me it does not. Since you're saying the image "fails", what is it it fails at? You're saying it couldn't be printed larger than 4x6 or something? Or even postage stamp size?

On a side note, you're probably not the one to ask (since you seem to think most people other than you are complete idiots...again something you share with your counterpart)...Anyhoo...in images that don't have enough pixel resolution, but still have "detail" (as in those I've done with the Foveon Generation "1" DP2 camera I used to own)...what is the correct technique for removing the "pixel blocking" that is still apparent after I scale up the image (either in PS or Perfect Resize 7)?

You will probably say there is no way, but it seems like there ought to be.


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