What would the Ideal MP be for a FF 1:1:1 Foveon DSLR?

Chris, your statement about a wider sensor gives me an idea. Since 4K (and surely 8K) screens are 16:9 format, why NOT make the sensor wide enough to fit that format best? They can make it taller, for people who want to shoot 3:2 and even for people who want to shoot 4:3 and 5:4, but why not make the sensor wider, to take best advantage of the image circle with a 16:9 format?

I guess it all depends on the production facilities a the time, but if it's feasible to make a 24x36 sensor, why not a 30x40 sensor? Leica did it, right? (Maybe it would be cost prohibitive, but maybe not. Maybe it wouldn't cost much more than a standard full-frame sensor size.) I can tell you for sure that Sigma does things differently, and THAT would REALLY make them stand out, huh? Imagine the huge viewfinder? lol

Hi, Scott -

Not sure whether a 40 x 30 would be cost-prohibitive, as "eating" so much of a wafer, but I thought that with this 16:9 ratio shaping our world more and more, a 38.4 x 21.6 mm might do, not requiring such a tall camera. I am aware of our field of vision, fans of the square format(Rollei, Hasselblad, etc...), yet it looks like most screens including smart phones tend towards 16:9 as well. Looking at all the paintings at the Louvre, it's also a minority that's square, as if the golden number had been a precursor to our letterboxed civilization !

How about a Peregrine Systems Silicon On Sapphire rainbow sensor (UltraCMOS) for Sigma, and a joint venture with Ushio to realize a stacked rainbow display, maybe with a DLP color wheel, or at least someone like Sharp that would have the patent coverage ?

Chris

cquarksnow said:

Hi, Scott -

Not sure whether a 40 x 30 would be cost-prohibitive, as "eating" so much of a wafer, but I thought that with this 16:9 ratio shaping our world more and more, a 38.4 x 21.6 mm might do, not requiring such a tall camera. I am aware of our field of vision, fans of the square format(Rollei, Hasselblad, etc...), yet it looks like most screens including smart phones tend towards 16:9 as well. Looking at all the paintings at the Louvre, it's also a minority that's square, as if the golden number had been a precursor to our letterboxed civilization !

Click to expand...

Not to mention the Panasonic models GH1 and GH2 which have aspect ratio options but all with the same diagonal size afforded by an over-sized sensor. I find the 1:1 quite useful (2992x2992px) but rarely use the 16:9.

Truman Prevatt said:

xpatUSA said:

Truman Prevatt said:

Can't speak for Laurence, however, in my case my workflow is judged by what is best hanging on the wall.

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So, may I ask the relevant questions - what size is the picture hanging on the wall and from how far away do you view it?

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I remember reading a long article some time (and I mean some time ) back by Ansel Adams on this subject based of the capabilities of the eye at different viewing angles. While the angle of view of the eye is large, the ability to differentiate a different levels what is seen varies greatly in angle. For example to differentiate and read text, the angle in which that can be down is on the order of 10 degrees. For differentiating shapes, it opens up to approximately 30 degrees. For differentiating color it was approximately 60 degrees. That means unless you only want to look at a small portion of a photography and be able assimilate the meaning the photographer communicating, you need to be back so that the diagonal of the print falls within a 30 degree angle that is +/- 15 degrees from the gaze point on the image.

There is a rule of thumb you can find on the Internet which is 1.5 to 2 times the diagonal. However, that results in a required angle of 50 to 66 degrees which is too wide. However, I guess if you are more interesting in the color 50 to 60 degrees might be fine. I don't do color so the ability to differentiate is what matters. For a B&W print I like a viewing distance of approximately 4 feet for an 8x10, 6 feet for a 11x14 and 8 feet for an 16x20 is what I consider optimal. That turns out to be 3.73 (=1/tan(15 degrees)) times the length of the diagonal.

I find that if I view a 8x10 at 1.5 the diagonal ( which would be a foot and 1/2) I have to "scan" the image to take it all in and in doing so it is difficult to take in the full meaning of the image and it loses something.

However, the perceptions of each person will vary. It might vary in color vs. B&W. Some want to be go close and examine one area of a print with no interest in seeing the holistic image as the photographer saw it. For me I want to see the print as a holistic image - not by scanning it.

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Thanks for the comprehensive response and good to see you're not one of those who goes up to a mural armed with a magnifying glass ;-)

I tried viewing my 19" (5:4) monitor at 48 inches but was thwarted by my bad eyesight in seeing any detail and neither pair of glasses helped. Could see what you mean by 'holistic image' though.

Ted some people have 20/20 vision. Some people have even better vision than that. In Peter Lik's galleries I have seen people step right up to the photo and inspect the fine detail from less than 12 inches away. I myself have done this. I did this when I visited Clyde Butcher's gallery too. In fact, I think I do this every time I see a large photo print . . . or painting (when I see fine detail). I remember looking very closely at the fine detail in Christian Lassen's paintings in his gallery in Las Vegas.

I think it's just something that people do. You really can't blame them, can you?

cquarksnow said:

Hi, Scott -

Not sure whether a 40 x 30 would be cost-prohibitive, as "eating" so much of a wafer, but I thought that with this 16:9 ratio shaping our world more and more, a 38.4 x 21.6 mm might do, not requiring such a tall camera. I am aware of our field of vision, fans of the square format(Rollei, Hasselblad, etc...), yet it looks like most screens including smart phones tend towards 16:9 as well. Looking at all the paintings at the Louvre, it's also a minority that's square, as if the golden number had been a precursor to our letterboxed civilization !

How about a Peregrine Systems Silicon On Sapphire rainbow sensor (UltraCMOS) for Sigma, and a joint venture with Ushio to realize a stacked rainbow display, maybe with a DLP color wheel, or at least someone like Sharp that would have the patent coverage ?

Chris

Click to expand...

I like the way you think Chris. Sigma obviously thinks out of the box, and we have to applaud them for that. Maybe they will add a fourth color to their sensor at some point. I hope they can experiment with such technology. I don't know about SOS, but it looks interesting. I wonder if it would make a difference or work at all. UltraCMOS would be good for marketing, right? lol

Scottelly said:

Ted some people have 20/20 vision.

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Such as those with a visual acuity of 0.3 mrad (1 minute of arc on the Snellen chart).

Scottelly said:

Some people have even better vision than that.

Click to expand...

Such as those with 0.1 mrad

Scottelly said:

In Peter Lik's galleries I have seen people step right up to the photo and inspect the fine detail from less than 12 inches away. I myself have done this. I did this when I visited Clyde Butcher's gallery too. In fact, I think I do this every time I see a large photo print . . . or painting (when I see fine detail). I remember looking very closely at the fine detail in Christian Lassen's paintings in his gallery in Las Vegas.

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$cott, I really don't know why I'm being told this. Have I said anywhere that people should not?

Scottelly said:

I think it's just something that people do. You really can't blame them, can you?

Click to expand...

Was I blaming them?

I've said again and again and again, ad nauseam, in this Forum that I DO NOT PRINT. I use a cheap NEC 1990 SX 1280x1024px monitor with 0.294mm dot pitch to view images at about 0.55m distance. Therefore, a 12MP FF is more than good enough for my purposes and I will NOT be persuaded otherwise. In fact, even the original 3.4MP is good enough for me in the original sensor size. I'm sure that my Polaroid x530, should it ever arrive, will perfectly adequate too.

--

Cheers,
Ted

Laurence Matson said:

On an Epson printer, an image looks great at 180 dpi, better at 360 dpi, even better at 720 dpi, etc.

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I didn't think the human eye could see more than 300dpi?

JackM said:

Laurence Matson said:

On an Epson printer, an image looks great at 180 dpi, better at 360 dpi, even better at 720 dpi, etc.

Click to expand...

I didn't think the human eye could see more than 300dpi?

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It depends on the viewing distance, because the average human eye acuity is defined as an angle. This fact is avoided at all costs in photography to dumb it down for the average Joe. So, for every dpi number, a viewing distance must also be quoted.

When I was a myopic kid, I could focus down to 4" from a subject. At that distance, I could distinguish things perhaps 0.005 degrees wide; that would be close to 2880 dpi !

Today, at 74, still myopic, I can't focus closer than about a foot, 90 dpi at best :-(

--
Cheers,
Ted

Scottelly said:

Ted some people have 20/20 vision. Some people have even better vision than that. In Peter Lik's galleries I have seen people step right up to the photo and inspect the fine detail from less than 12 inches away. I myself have done this. I did this when I visited Clyde Butcher's gallery too. In fact, I think I do this every time I see a large photo print . . . or painting (when I see fine detail). I remember looking very closely at the fine detail in Christian Lassen's paintings in his gallery in Las Vegas.

Click to expand...

You can go as close as you want to a Clyde Butcher print. A 16x20 is only enlarged by only 2 X!. It's almost a contact print. That sucker still lugs around his 8x10 slugging through the South Florida swamp and as of yet to be ate by an alligator ;-).

I don't know if you have seen his dark room in Venice. It is truly amazing.

xpatUSA said:

Was I blaming them?

I've said again and again and again, ad nauseam, in this Forum that I DO NOT PRINT. I use a cheap NEC 1990 SX 1280x1024px monitor with 0.294mm dot pitch to view images at about 0.55m distance. Therefore, a 12MP FF is more than good enough for my purposes and I will NOT be persuaded otherwise. In fact, even the original 3.4MP is good enough for me in the original sensor size. I'm sure that my Polaroid x530, should it ever arrive, will perfectly adequate too.

--

Cheers,
Ted

Click to expand...

Today with direct digital capture - images can easily be viewed directly on electronic displays. That is relatively new, however, in the history of photography. I still think it makes sense to break the forums up based on what the final display output one seeks. It actually makes little sense to talk about "viewing in 100%" if you final output device is the printer unless that small part of the image is how you are going to crop a print.

It really makes no sense to talk about "holistic meaning of the whole image" if one wants to view it from half a meter away on a large monitor at 72 dpi. The final output does matter in all aspects of photography.

The choice of the final output permeates all the decisions that are to be made about an image.

Long ago, I held my only show ever at a small gallery in Hanover, NH. The title was The End of Viewing Distance. It garnered some attention, in particular from some members of this forum as well as a couple of museum directors, some guy and his family from Foveon, and local, prominent photographers. For me, the more important thing was watching the attendees put their noses on the prints.

An example of this is the second image from the top in Lawrence's report.


The print is 17 feet wide, so the "normal" viewing distance should be pretty far back.

We can argue all we want about viewing distance. However, I have been working on another approach since the 1970s, and the relatively recent adoption of Sigma digital cameras, with their higher degree of pixel-level acuity, make it easier to achieve a different image in print than in the film days.

My first step in the digital age was to learn to print without or with a minimum of visible artifacts. When Dominic and I did the large photokina show ten years ago (many prints), we focussed on this problem. During the show, we noticed that people invariably moved towards the prints for a "closer look" as if the concept of viewing distance as determined by print size was gone.


As I refined my printing skills and started making large panorama-matrix images, I also noted that these huge images attracted viewers to take a closer look rather than pushing them away. However, in some cases, the images at 180 dpi were much larger than I could print.

This image is 2 meters x 2.4 meters at 180 dpi.


Obviously, that is too large for a 44-inch printer, so instead of resampling, I changed the dpi to 360. The result was a print that has even greater "attraction" than the 180 prints.

I continued to follow that tack and found that smaller 720 dpi prints exhibit this attraction even more. I have these prints hanging around the house and have watched people's viewing patterns and proximity for six years now.

My conclusions based on consistent viewing habits are:

- good clean pixels always draw people closer
- greater density seems to have a greater attraction
- a complete lack of artifacts combined with high density pixels is exceptionally attractive

As a counter observation, I had an interesting experience at the Epson booth for Digigraphie at the Paris show a while back. The prints there looked great as I approached the booth. But once inside, I could see how horrible they really were and said so to the Epson rep there. He admitted as much as said that he had to put them up for "marketing reasons." They had been done by one of the world's most famous aerial photographers and a well-known sailing photographer. Since he knew who I was, he asked if we could go to the Sigma booth to look at what was there that year.

All of this is not to bristle my buttons but rather to encourage those who want to print to try to get their heads around the concept of maximum information for prints. It is easy to understand that in terms of spatial location counts. However, consider how much information is in each location and in what form. Most people understand the information difference between 8 bit and 16 bit. However, there is also a tremendous information difference between a Foveon spatial location and a Bayer spatial location.

In principle, one should maintain the highest level of clean information possible for as long as possible in a march to a fine print.

Laurence Matson said:

On an Epson printer, an image looks great at 180 dpi, better at 360 dpi, even better at 720 dpi, etc.

The more information I can provide to a fixed-dimension output space (a print as opposed to a monitor), the better. Anyone who claims otherwise is just settling for "good enough."

The print is all about information: as much information as possible processed correctly.

Punkt!

xpatUSA said:

I'm talking real geometric pixel resolution, not the X3 obfuscation

Respondents should consider the following assertion:

"Only few output media like large fine art printers support resolutions in excess of 10 MP."

Found in Section 1.3.1 here:

http://falklumo.blogspot.com/2012/06/true-reasons-full-frame.html

Those respondents who check 'More' should at least tell us where to find SA mount lenses to match ;-)

Click to expand...

Click to expand...

Truman Prevatt said:

The choice of the final output permeates all the decisions that are to be made about an image.

Click to expand...

Amen to that

Laurence Matson said:

The print is 17 feet wide, so the "normal" viewing distance should be pretty far back.

--

Click to expand...

I don't think there is a "best" viewing distance. In many respect it depends on the object. It really doesn't matter if it is painting, drawing, sculpture or photography. For example it makes no sense to say one has to view the images of Michelangelo in the Sistine Chapel ceiling the same relative distance that one would view the Mona Lisa. If you go to a Museum you may not view huge painting by Salvador Dali at some distance dictated by the diagonal. That is simply because a Dali painting does not consist of a single painting - or even a single subject but he tells a story within a painting. However, using Dali again, he has one painting called Gala Contemplating the Mediterranean Sea. When viewed up close the painting makes absolutely no sense. However, when viewed much farther then the "normal" viewing distance - at least 20 feet away - it is a image of Abraham Lincoln. It was the impetus of a lithograph Lincoln in Dalivation.


Try an experiment - stand back about 2 feet and put your glaze point at the center of the center of the image. Now keeping your glaze point fixed describe details of the wall or objects, etc. 10 degrees off, 15 degrees off, 20 degrees off, etc. What you will, not batter if you are 20/20 or not the ability to desert even shape declines with angle.

From the line to the gazing point to the center of the nose, what is more important that the total filed of view is the differentiable angle. Plus and minus 5 degrees humans can differentiate text. Up to +/- 15 degrees they can differentiate shape. Up to +/-30 degrees they can differentiate color. Beyond this is the peripheral vision - something is there better look. Here is an interesting article on how MIT is working to expand the human visual perception system.


The total field of view of the eye of a person looking at a piece of artwork is often obtained by scanning the glazing point around. Hence if you want to get a holistic view of the message of the photographer, you need to be where your vision can support that with a gaze point so that you brain does not have to reassemble the image. If you want to peer at detail then you have to get close. However, in doing so you will lose the impression of the image in its whole.

What you want to see is a personal perspective. If your goal of looking at an image is to see the local detail - then you want to go close (no matter how large the image) and inspect the detail. If on the other hand you want to see the holistic message. I've hung work in galleries that would limit the distance between the viewers - the distance depending on the format. If you want to inspect a print they they will get one for you to inspect.

However, my preference is I don't want to look at the brush stories on the Mona Lisa. I want to stand back and take in the woman's beauty. I don't want to look at the Moonrise or Immigrant Mother in my living room with my nose against the glass with a lope. I want to stand back and enjoy the wonderful message iconic message that Adams was sending with Moonrise and the message on the human condition that Lange was communicating.

To each their own.

Truman
www.pbase.com/tprevatt

xpatUSA said:

Scottelly said:

Ted some people have 20/20 vision.

Click to expand...

Such as those with a visual acuity of 0.3 mrad (1 minute of arc on the Snellen chart).

xpatUSA said:

Some people have even better vision than that.

Click to expand...

Such as those with 0.1 mrad

xpatUSA said:

In Peter Lik's galleries I have seen people step right up to the photo and inspect the fine detail from less than 12 inches away. I myself have done this. I did this when I visited Clyde Butcher's gallery too. In fact, I think I do this every time I see a large photo print . . . or painting (when I see fine detail). I remember looking very closely at the fine detail in Christian Lassen's paintings in his gallery in Las Vegas.

Click to expand...

$cott, I really don't know why I'm being told this. Have I said anywhere that people should not?

xpatUSA said:

I think it's just something that people do. You really can't blame them, can you?

Click to expand...

Was I blaming them?

I've said again and again and again, ad nauseam, in this Forum that I DO NOT PRINT. I use a cheap NEC 1990 SX 1280x1024px monitor with 0.294mm dot pitch to view images at about 0.55m distance. Therefore, a 12MP FF is more than good enough for my purposes and I will NOT be persuaded otherwise. In fact, even the original 3.4MP is good enough for me in the original sensor size. I'm sure that my Polaroid x530, should it ever arrive, will perfectly adequate too.

--

Cheers,
Ted

Click to expand...

Sorry Ted. I guess my point is that we are nowhere near the resolution we SHOULD be at, for all situations (the whole reason people want more than 8 MP cameras, even in their cell phones, is because they don't JUST want to view their photos full-screen on a low resolution screen). In 10 years there very well might be 100 MP point-and-shoot cameras . . . maybe even 200 MP cameras. As we all seem to know, Sigma makes cameras for those who care about how much detail is clearly visible in their photos. Your argument that what you get from an old camera is penty for you just doesn't apply here, does it? If it did, why wouldn't you suggest we go back to sensors that produce a 4.7 MP image? Certainly a 4.7 MP (4.7 x 3) full-frame Foveon sensor would capture incredibly noise-free images, right? I don't see the point in making a full-frame sensor like that, but the camera would surely work very quickly, and the photos would write to the memory card like lightning.

Truman Prevatt said:

Laurence Matson said:

The print is 17 feet wide, so the "normal" viewing distance should be pretty far back.

--

Click to expand...

I don't think there is a "best" viewing distance. In many respect it depends on the object. It really doesn't matter if it is painting, drawing, sculpture or photography. For example it makes no sense to say one has to view the images of Michelangelo in the Sistine Chapel ceiling the same relative distance that one would view the Mona Lisa. If you go to a Museum you may not view huge painting by Salvador Dali at some distance dictated by the diagonal. That is simply because a Dali painting does not consist of a single painting - or even a single subject but he tells a story within a painting. However, using Dali again, he has one painting called Gala Contemplating the Mediterranean Sea. When viewed up close the painting makes absolutely no sense. However, when viewed much farther then the "normal" viewing distance - at least 20 feet away - it is a image of Abraham Lincoln. It was the impetus of a lithograph Lincoln in Dalivation.

http://en.wikipedia.org/wiki/Lincoln_in_Dalivision

Try an experiment - stand back about 2 feet and put your glaze point at the center of the center of the image. Now keeping your glaze point fixed describe details of the wall or objects, etc. 10 degrees off, 15 degrees off, 20 degrees off, etc. What you will, not batter if you are 20/20 or not the ability to desert even shape declines with angle.

From the line to the gazing point to the center of the nose, what is more important that the total filed of view is the differentiable angle. Plus and minus 5 degrees humans can differentiate text. Up to +/- 15 degrees they can differentiate shape. Up to +/-30 degrees they can differentiate color. Beyond this is the peripheral vision - something is there better look. Here is an interesting article on how MIT is working to expand the human visual perception system.

http://www.technologyreview.com/vie...lity-interface-exploits-human-nervous-system/

The total field of view of the eye of a person looking at a piece of artwork is often obtained by scanning the glazing point around. Hence if you want to get a holistic view of the message of the photographer, you need to be where your vision can support that with a gaze point so that you brain does not have to reassemble the image. If you want to peer at detail then you have to get close. However, in doing so you will lose the impression of the image in its whole.

What you want to see is a personal perspective. If your goal of looking at an image is to see the local detail - then you want to go close (no matter how large the image) and inspect the detail. If on the other hand you want to see the holistic message. I've hung work in galleries that would limit the distance between the viewers - the distance depending on the format. If you want to inspect a print they they will get one for you to inspect.

However, my preference is I don't want to look at the brush stories on the Mona Lisa. I want to stand back and take in the woman's beauty. I don't want to look at the Moonrise or Immigrant Mother in my living room with my nose against the glass with a lope. I want to stand back and enjoy the wonderful message iconic message that Adams was sending with Moonrise and the message on the human condition that Lange was communicating.

To each their own.

Truman
www.pbase.com/tprevatt

Click to expand...

Truman, I think pretty much everyone would agree with you . . . and Ted . . . for NORMAL viewing. But people don't JUST view images in a normal way from a normal viewing distance. Their view changes. They zoom in and out of the image or walk up to the print and view it from close-up. It happens all the time. When I watch movies, I like to sit in one spot and see the whole thing, but when I look at a still image, I treat it differently. I look at the whole thing, and then I look at one part . . . and then another. Then I might look more closely, by moving my head in toward the screen or print . . . or if it is in a magazine I might bring the magazine closer to my face, to inspect various elements of the image. I'm sure YOU do this too. It is THIS type of viewing that makes me and most other people want more resolution, even though today we have 4 times the resolution (or twice as much horizontally) than we had when digital cameras were good enough for most people to buy one and stop shooting with film cameras.

Scottelly said:

xpatUSA said:

Scottelly said:

Ted some people have 20/20 vision.

Click to expand...

Such as those with a visual acuity of 0.3 mrad (1 minute of arc on the Snellen chart).

Scottelly said:

Some people have even better vision than that.

Click to expand...

Such as those with 0.1 mrad

Scottelly said:

In Peter Lik's galleries I have seen people step right up to the photo and inspect the fine detail from less than 12 inches away. I myself have done this. I did this when I visited Clyde Butcher's gallery too. In fact, I think I do this every time I see a large photo print . . . or painting (when I see fine detail). I remember looking very closely at the fine detail in Christian Lassen's paintings in his gallery in Las Vegas.

Click to expand...

$cott, I really don't know why I'm being told this. Have I said anywhere that people should not?

Scottelly said:

I think it's just something that people do. You really can't blame them, can you?

Click to expand...

Was I blaming them?

I've said again and again and again, ad nauseam, in this Forum that I DO NOT PRINT. I use a cheap NEC 1990 SX 1280x1024px monitor with 0.294mm dot pitch to view images at about 0.55m distance. Therefore, a 12MP FF is more than good enough for my purposes and I will NOT be persuaded otherwise. In fact, even the original 3.4MP is good enough for me in the original sensor size. I'm sure that my Polaroid x530, should it ever arrive, will perfectly adequate too.

--

Cheers,
Ted

Click to expand...

Sorry Ted.

Click to expand...

That's OK.

Scottelly said:

I guess my point is that we are nowhere near the resolution we SHOULD be at, for all situations (the whole reason people want more than 8 MP cameras, even in their cell phones, is because they don't JUST want to view their photos full-screen on a low resolution screen). In 10 years there very well might be 100 MP point-and-shoot cameras . . . maybe even 200 MP cameras. As we all seem to know, Sigma makes cameras for those who care about how much detail is clearly visible in their photos.

Click to expand...

Your point is well made on the behalf of 'people'.

Scottelly said:

Your argument that what you get from an old camera is plenty for you just doesn't apply here, does it?

Click to expand...

WTF do you mean "just doesn't apply here"? And it was not an 'argument'. I am not trying to persuade anybody of anything on this subject. Just a simple statement of what I do and, more importantly, why I do it.

Scottelly said:

If it did, why wouldn't you suggest we go back to sensors that produce a 4.7 MP image?

Click to expand...

Again, I make no suggestions in this thread as to what 'we' should or should not do. I put up a poll to see what people think.

Scottelly said:

Certainly a 4.7 MP (4.7 x 3) full-frame Foveon sensor would capture incredibly noise-free images, right?

Click to expand...

Wrong. IMHO, the Foveon sensor is inherently noisy, almost irrespective of pixel size.

Scottelly said:

I don't see the point in making a full-frame sensor like that

Click to expand...

Fine. Pardon my pique.

Hi, Scott -

Tom Shum certainly had a point, and here is the transmittance of sapphire, that is over 75% in the visible spectrum in comparison with silicon. There would be so little noise that alternative developers like Rawdigger would not need to spend time on denoising, and the aggregate with an heptachrome sensor would also be negligible.


SOI / SOS transmittance comparison

Peregrine Systems (just acquired by Murata) , Sensonetics, Soitec (France), Silanna (Australia) are big players in the SOS world....

Chris

cquarksnow said:

<..>

How about a Peregrine Systems Silicon On Sapphire rainbow sensor (UltraCMOS) for Sigma . .

Chris

Click to expand...

Quite an intriguing thought that . . . but what is the thickness of the UltraCMOS silicon layer?

WikiPedia says "Silicon on sapphire (SOS) is a hetero-epitaxial process for integrated circuit manufacturing that consists of a thin layer (typically thinner than 0.6µm) of silicon grown on a sapphire wafer."

Whereas don't the Foveon layers need a total of at least 10 times that thickness?

Hi, Ted -

I don't know what it would be for a visible light sensor application, but I was mainly referring to Psemi Ultra-Thin-Silicon (UTSi®) on sapphire substrates, part of their UltraCMOS® technology.
For RF applications, they wind up with 0.5 µm and 0.25 µm gates.
I can imagine that besides patent issues, it would be a long empirical R&D, and I am not sure yet whether it has been looked at by the photographic industry, besides aerospace and military applications. Maybe someone like Eric Fossum would know ?

I have not found depth of penetration curves, like the ones in that white paper http://www.aphesa.com/downloads/download2.php?id=1 on silicon.



Chris