Final output of the Foveon X3 ?

Boris

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Up to this point in this age of digital technology I found that all things being equal go with more pixels if you want to print your pictures larger. That is the reason I have a 6mp DSLR. So my 6mp file is 3024x2016 if I want to print a 18x12in. (Epson 1280) my printing resolution is 168 pixel/inch.... barely acceptable. So here is the question, the Sigma Foveon is 2268x1512 so if I want to print 18x12in. will be at 125pixels/inch. Will the Foveon X3 CMOS produce a much better 18X12in. print compared to the present 6mp DSLR?

Boris
 
... Will the Foveon X3 CMOS
produce a much better 18X12in. print compared to the present 6mp
DSLR?
Seems to me that the way to get some insight into this is to do your own
comparisons of your images from a Bayer CFA camera with images
in which you make nearly ideally "real pixels" by downsizing a very
high-res capture of a scene. It shouldn't be hard to simulate a small
X3 sensor, say 1 MP, by downsizing a 6 MP image, and then reframe
and see how many of your pixels you need to use to match the
sharpness and quality, say on 5x7 or 8x10 prints.

Has anyone tried that?

B.S. Cutter, consultant
 
Up to this point in this age of digital technology I found that all
things being equal go with more pixels if you want to print your
pictures larger. That is the reason I have a 6mp DSLR. So my 6mp
file is 3024x2016 if I want to print a 18x12in. (Epson 1280) my
printing resolution is 168 pixel/inch.... barely acceptable. So
here is the question, the Sigma Foveon is 2268x1512 so if I want to
print 18x12in. will be at 125pixels/inch. Will the Foveon X3 CMOS
produce a much better 18X12in. print compared to the present 6mp
DSLR?
There are some samples floating around here. They probably will give you very optimistic "preview" but never the less you can do you tests now. And tell us the answer...
 
Up to this point in this age of digital technology I found that all
things being equal go with more pixels if you want to print your
pictures larger. That is the reason I have a 6mp DSLR. So my 6mp
file is 3024x2016 if I want to print a 18x12in. (Epson 1280) my
printing resolution is 168 pixel/inch.... barely acceptable. So
here is the question, the Sigma Foveon is 2268x1512 so if I want to
print 18x12in. will be at 125pixels/inch. Will the Foveon X3 CMOS
produce a much better 18X12in. print compared to the present 6mp
DSLR?
There are some samples floating around here. They probably will
give you very optimistic "preview" but never the less you can do
you tests now. And tell us the answer...
I haven't found any full resolution 2268x1512 from the Sigma Foveon.....
Boris
http://public.fotki.com/borysd/
 
Hi Boris

It's the wrong question.

When you are using a bayer pattern sensor the camera is interpolating UP for you to get that 6MP file.

The Sigma is not doing this interpolation

Your D100 or D60 is ALSO interpolating the colors.

Neither of these takes place (or at least not to the same degree in the Foveon chip).

So to get the enlargement you are seeking you would have to interpolate your Sigma image up and you would also being interpolating your Canon or Nikon Up, but in that case you would be starting with an interpolated image.

Dave
Up to this point in this age of digital technology I found that all
things being equal go with more pixels if you want to print your
pictures larger. That is the reason I have a 6mp DSLR. So my 6mp
file is 3024x2016 if I want to print a 18x12in. (Epson 1280) my
printing resolution is 168 pixel/inch.... barely acceptable. So
here is the question, the Sigma Foveon is 2268x1512 so if I want to
print 18x12in. will be at 125pixels/inch. Will the Foveon X3 CMOS
produce a much better 18X12in. print compared to the present 6mp
DSLR?
There are some samples floating around here. They probably will
give you very optimistic "preview" but never the less you can do
you tests now. And tell us the answer...
I haven't found any full resolution 2268x1512 from the Sigma
Foveon.....
Boris
http://public.fotki.com/borysd/
 
I haven't found any full resolution 2268x1512 from the Sigma
Foveon.....
I saw some just yesterday. They's samples on the website were full resolution at some point in time and some people still have them. I saw posted saples recently. If I would have them saved I would send them to you. But...
 
I understand the color interpolation, but please tell me why you think the camera is interpolating resolution as well? There are 6Mp worth of datasites on the sensor, unlike a SuperCCD where there are 6Mp but the output file has 12Mp. As far as I know the other CCD/CMOS cameras do not interpolate resolution. But please tell me if I am wrong here.

The Sigma print at its' native resolution would be of poorer quality at the 12x18 size vs the 6Mp, time will tell if the SD-9 image will look better when upresed to 6Mp.
It's the wrong question.

When you are using a bayer pattern sensor the camera is
interpolating UP for you to get that 6MP file.

The Sigma is not doing this interpolation

Your D100 or D60 is ALSO interpolating the colors.

Neither of these takes place (or at least not to the same degree in
the Foveon chip).

So to get the enlargement you are seeking you would have to
interpolate your Sigma image up and you would also being
interpolating your Canon or Nikon Up, but in that case you would be
starting with an interpolated image.

Dave
Up to this point in this age of digital technology I found that all
things being equal go with more pixels if you want to print your
pictures larger. That is the reason I have a 6mp DSLR. So my 6mp
file is 3024x2016 if I want to print a 18x12in. (Epson 1280) my
printing resolution is 168 pixel/inch.... barely acceptable. So
here is the question, the Sigma Foveon is 2268x1512 so if I want to
print 18x12in. will be at 125pixels/inch. Will the Foveon X3 CMOS
produce a much better 18X12in. print compared to the present 6mp
DSLR?
There are some samples floating around here. They probably will
give you very optimistic "preview" but never the less you can do
you tests now. And tell us the answer...
I haven't found any full resolution 2268x1512 from the Sigma
Foveon.....
Boris
http://public.fotki.com/borysd/
--
Valliesto
'A hero is no braver than an ordinary man, but he is brave five
minutes longer.'
  • R.W. Emerson
 
That is the reason I have a 6mp DSLR. So my 6mp
file is 3024x2016 if I want to print a 18x12in. (Epson 1280) my
printing resolution is 168 pixel/inch.... barely acceptable. So
here is the question, the Sigma Foveon is 2268x1512 so if I want to
print 18x12in. will be at 125pixels/inch. Will the Foveon X3 CMOS
produce a much better 18X12in. print compared to the present 6mp
DSLR?
According to Phil, he sees a 4:1 differences, one would need to downsample a 6mp Bayer image down to 1.5mp in order to see the same level of detail Foveon offers.
http://www.dpreview.com/forums/read.asp?forum=1014&message=3432204

--
jc
Sony F707
http://www.reefkeepers.org/gallery/f707
http://www.reeftec.com/gallery
 
Hi Valliesto

It's my understanding that in fact it takes twice as many sensors to make one image pixel then with the Foveon. On a D100 for example, you are in effect having a 3MP camera. It then interpolates up to get the 6MP.

In addition there is also the color interpolation of the bayer pattern sensor.

Jump into the following thread:

http://www.dpreview.com/forums/read.asp?forum=1000&message=3423799

My cheif contribution to this thread is a constant high pitch whinning that they aren't explaining this in layperson terms. But in fact such is the case - Previous rating systems are "false." The Foveon sensor is going to force the science writers to rethink the way they write about this.

Dave
The Sigma print at its' native resolution would be of poorer
quality at the 12x18 size vs the 6Mp, time will tell if the SD-9
image will look better when upresed to 6Mp.
It's the wrong question.

When you are using a bayer pattern sensor the camera is
interpolating UP for you to get that 6MP file.

The Sigma is not doing this interpolation

Your D100 or D60 is ALSO interpolating the colors.

Neither of these takes place (or at least not to the same degree in
the Foveon chip).

So to get the enlargement you are seeking you would have to
interpolate your Sigma image up and you would also being
interpolating your Canon or Nikon Up, but in that case you would be
starting with an interpolated image.

Dave
Up to this point in this age of digital technology I found that all
things being equal go with more pixels if you want to print your
pictures larger. That is the reason I have a 6mp DSLR. So my 6mp
file is 3024x2016 if I want to print a 18x12in. (Epson 1280) my
printing resolution is 168 pixel/inch.... barely acceptable. So
here is the question, the Sigma Foveon is 2268x1512 so if I want to
print 18x12in. will be at 125pixels/inch. Will the Foveon X3 CMOS
produce a much better 18X12in. print compared to the present 6mp
DSLR?
There are some samples floating around here. They probably will
give you very optimistic "preview" but never the less you can do
you tests now. And tell us the answer...
I haven't found any full resolution 2268x1512 from the Sigma
Foveon.....
Boris
http://public.fotki.com/borysd/
--
Valliesto
'A hero is no braver than an ordinary man, but he is brave five
minutes longer.'
  • R.W. Emerson
 
No.

The advantages are in better reproduced colour and lack of moiré patterns in certain situations.

There is no real gain in sharpness or picture resolution.
Up to this point in this age of digital technology I found that all
things being equal go with more pixels if you want to print your
pictures larger. That is the reason I have a 6mp DSLR. So my 6mp
file is 3024x2016 if I want to print a 18x12in. (Epson 1280) my
printing resolution is 168 pixel/inch.... barely acceptable. So
here is the question, the Sigma Foveon is 2268x1512 so if I want to
print 18x12in. will be at 125pixels/inch. Will the Foveon X3 CMOS
produce a much better 18X12in. print compared to the present 6mp
DSLR?

Boris
--
Derek
 
It's my understanding that in fact it takes twice as many sensors
to make one image pixel then with the Foveon.
People are quibbling over the exact numbers. Some say 1.4x some say 2x. (Some say > 3x or better, but are not credible.)

Answering this with actual cameras and sensors is the $64M question.....
On a D100 for
example, you are in effect having a 3MP camera. It then
interpolates up to get the 6MP.
First, there is no single way to do de-mosiacing. You just have to look at Phils side-by-side tests of cameras that use the same Sony sensor to see that how different mfgs do better/worse. But even in gross outline, your description is inaccurate. The image is NOT resampled down and then upsampled. Each sensor site can be calculated independently with wieghted information from neighboring pixels. Even the SuperCCD is similar, except that the calculated sites do not correspond exactly with pixel sites. SuperCCD does NOT generate a 6MP image and then upsize it.
In addition there is also the color interpolation of the bayer
pattern sensor.
Here is your mistake. It's no "in addition". It's the only interpolation that goes on.

--
Erik
 
Hi Eric

I am not writing as a tech, but as a layperson. Your post seems at least to contradict itself.
It's my understanding that in fact it takes twice as many sensors
to make one image pixel then with the Foveon.
People are quibbling over the exact numbers. Some say 1.4x some say
2x. (Some say > 3x or better, but are not credible.)
What I've been able to get out of listening to techs is that the Foveon chip gives you true data and the bayer chip does much more interpolation. So reading the above seems to confirm that - i.e. higher resolution.
On a D100 for
example, you are in effect having a 3MP camera. It then
interpolates up to get the 6MP.
First, there is no single way to do de-mosiacing. You just have to
look at Phils side-by-side tests of cameras that use the same Sony
sensor to see that how different mfgs do better/worse. But even in
gross outline, your description is inaccurate. The image is NOT
resampled down and then upsampled. Each sensor site can be
calculated independently with wieghted information from neighboring
pixels. Even the SuperCCD is similar, except that the calculated
sites do not correspond exactly with pixel sites. SuperCCD does NOT
generate a 6MP image and then upsize it.
Well here you lose me. My point is that the standard rating exagerates the existing bayer pattern chip. How different companies assemble their mosaic is beside the point. If for example (and yes this example is not accurate) it takes two sensors on a bayer chip to make one image pixel and it takes one sensor on a Foveon chip to make a pixel, then the resulting 2 pixels on the bayer sensor is a result of interpolation. IOW the ratings are misleading.
In addition there is also the color interpolation of the bayer
pattern sensor.
Here is your mistake. It's no "in addition". It's the only
interpolation that goes on.
The top of your post and the bottom of your post are in contradiction. I realise you disagree, but that's the way it reads.
Dave
 
The way I read it, it depends :-)

Technically, the Foveon X3 has an 'equivalent' color resolution of 3x3.54Mp=10.62Mp compared to a Bayer sensor. However, you basically have three pixels (RGB) occupying the same physical two-dimensional space on the image plane. While this can provide a 'truer' image, it may or may not automatically translate into increased resolution.

That said, the Bayer must conversely have a lower resultant resolution, necessitated by the fact that you're using adjacent pixels of differing colors that are crunched using complex imaging algorithms in an attempt to derive a final image that more or less approximates the original source. The success or failure seems to depend more on the quality of the algorithm than the sensor resolution, as we see with the Canon G2's apparent better image quality using a 4Mp sensor than some cameras using 5 or even 6Mp.

As far as final output on paper, one would think one could upsample the Foveon image using a dithering algorithm and achieve a similar result to a conventional 'higher resolution' sensor.

-gl
Up to this point in this age of digital technology I found that all
things being equal go with more pixels if you want to print your
pictures larger. That is the reason I have a 6mp DSLR. So my 6mp
file is 3024x2016 if I want to print a 18x12in. (Epson 1280) my
printing resolution is 168 pixel/inch.... barely acceptable. So
here is the question, the Sigma Foveon is 2268x1512 so if I want to
print 18x12in. will be at 125pixels/inch. Will the Foveon X3 CMOS
produce a much better 18X12in. print compared to the present 6mp
DSLR?

Boris
 
I am not writing as a tech, but as a layperson. Your post seems at
least to contradict itself.
OK. For the lay person:
1. More MP does not equal more quality

2. X3 and Bayer sensors are different enough that there is no simple description of how they relate to each other on a MP x MP basis.
3. Buy the one that produces the images that look best to you.
What I've been able to get out of listening to techs is that the
Foveon chip gives you true data and the bayer chip does much more
interpolation.
First X3 does not give you "true" data. It only gives you data from 3 different color channels from a single location. Mosaic sensors use data from a single location plus some additional nearby locations. However, for comparable price, you can currently get twice as many mosaic locations.

Which produces better photos? See 1, 2, & 3 above.
Well here you lose me. My point is that the standard rating
exagerates the existing bayer pattern chip.
Since the standard rating is for mosaic sensors, it better to say that the X3 technology is "underrated". I'm not going to get into a discussion as exactly by how much because the only reasonable answer is "it depends."
How different companies assemble their mosaic is beside the point.
No, it's precisely the point. Theoretical cameras can only take theoretical pictures. Exactly how much data a camera recovers from its sensor depends on the implementation. It even depends on the type of scene that you are photographing.
IOW the ratings are misleading.
That's like saying a car's engine displacement is misleading because it does not tell you how fast it goes. (X3 = turbo? ;-). It's only misleading if you don't know what it means.
The top of your post and the bottom of your post are in
contradiction. I realise you disagree, but that's the way it reads.
The point I was trying to clarify is that there is only one "interpolation" step performed. Your description implied that both resolution and color were interpolated separately and that was inaccurate.

--
Erik
 
Thank you, and I think you are saying that theoretically the 3.54Mp Foveon should produce a print that is equal to the 6Mp Bayer? That is darn good......can't wait for the 6Mp Foveon...without the Sigma mount.
Pretty exiting times for Photo Buffs!
Boris
Technically, the Foveon X3 has an 'equivalent' color resolution of
3x3.54Mp=10.62Mp compared to a Bayer sensor. However, you
basically have three pixels (RGB) occupying the same physical
two-dimensional space on the image plane. While this can provide a
'truer' image, it may or may not automatically translate into
increased resolution.

That said, the Bayer must conversely have a lower resultant
resolution, necessitated by the fact that you're using adjacent
pixels of differing colors that are crunched using complex imaging
algorithms in an attempt to derive a final image that more or
less approximates the original source. The success or failure
seems to depend more on the quality of the algorithm than the
sensor resolution, as we see with the Canon G2's apparent better
image quality using a 4Mp sensor than some cameras using 5 or even
6Mp.

As far as final output on paper, one would think one could upsample
the Foveon image using a dithering algorithm and achieve a similar
result to a conventional 'higher resolution' sensor.

-gl
Up to this point in this age of digital technology I found that all
things being equal go with more pixels if you want to print your
pictures larger. That is the reason I have a 6mp DSLR. So my 6mp
file is 3024x2016 if I want to print a 18x12in. (Epson 1280) my
printing resolution is 168 pixel/inch.... barely acceptable. So
here is the question, the Sigma Foveon is 2268x1512 so if I want to
print 18x12in. will be at 125pixels/inch. Will the Foveon X3 CMOS
produce a much better 18X12in. print compared to the present 6mp
DSLR?

Boris
 
Hi Eric

I'm still confused. There's another thread on this subject (did I say another thread, perhaps twenty or thirty)

Bob Williams is the man I vaguely understood. Perhaps you can check out these posts and explain them to me:

http://www.dpreview.com/forums/read.asp?forum=1000&message=3423799

Dave
I am not writing as a tech, but as a layperson. Your post seems at
least to contradict itself.
OK. For the lay person:
1. More MP does not equal more quality
2. X3 and Bayer sensors are different enough that there is no
simple description of how they relate to each other on a MP x MP
basis.
3. Buy the one that produces the images that look best to you.
What I've been able to get out of listening to techs is that the
Foveon chip gives you true data and the bayer chip does much more
interpolation.
First X3 does not give you "true" data. It only gives you data from
3 different color channels from a single location. Mosaic sensors
use data from a single location plus some additional nearby
locations. However, for comparable price, you can currently get
twice as many mosaic locations.

Which produces better photos? See 1, 2, & 3 above.
Well here you lose me. My point is that the standard rating
exagerates the existing bayer pattern chip.
Since the standard rating is for mosaic sensors, it better to say
that the X3 technology is "underrated". I'm not going to get into a
discussion as exactly by how much because the only reasonable
answer is "it depends."
How different companies assemble their mosaic is beside the point.
No, it's precisely the point. Theoretical cameras can only take
theoretical pictures. Exactly how much data a camera recovers from
its sensor depends on the implementation. It even depends on the
type of scene that you are photographing.
IOW the ratings are misleading.
That's like saying a car's engine displacement is misleading
because it does not tell you how fast it goes. (X3 = turbo? ;-).
It's only misleading if you don't know what it means.
The top of your post and the bottom of your post are in
contradiction. I realise you disagree, but that's the way it reads.
The point I was trying to clarify is that there is only one
"interpolation" step performed. Your description implied that
both resolution and color were interpolated separately and that was
inaccurate.

--
Erik
 
OK. For the lay person:
1. More MP does not equal more quality
2. X3 and Bayer sensors are different enough that there is no
simple description of how they relate to each other on a MP x MP
basis.
1. Nope, more MP for mosaic sensors does not mean better quality, and Foveon has proven this to be the case.

2. Correct, and this is why we now need to think of pixels as image pixels, and not photsite pixels.
First X3 does not give you "true" data. It only gives you data from
3 different color channels from a single location. Mosaic sensors
use data from a single location plus some additional nearby
locations. However, for comparable price, you can currently get
twice as many mosaic locations.
X3 does give you true data in term of the RGB color space. Each pixel within the Foevon chip can store the full range RGB value between (0,0,0) to (255,255,255). So each pixel is a true RGB representation w/o any guess work. Whereas mosaic sensors cannot do this. A mosaic sensor requires a min of 2x2 photosites to generate the same RGB color space, and even that requires some guess work as each photosite only capture one portion of the RGB, not all three. This little detail by itself means a 2x2 Foveon photosite area can contain four totally unrelated RGB color data, whereas a mosaic sensor cannot. So by this alone, a Foveon sensor can resolve details down to the photosite level, whereas the mosaic sensor can only resolve down to the 2x2 photosite area as anything smaller requires guess work. This differences alone means Foveon resolves better and is more sharp then mosaic sensors when we compare MP vs MP.

If you think of the mosaic sensor as four small cups placed next to each other and are inter-connected, like the ASCII graphic below,

0-0
X
0-0

Then you will see that when you pour different color paint into each O cup, the color of each cup will also leak into the other 3 O cups, hence mixing all of the colors together.

The X3 do not have the interconnection, so each cup will only contain whatever color that is in that cup and not be effected by the other three cups.

To further show the point ...

Here is a resolution chart of a 2048x2048 X3 chip ...



vs a 3072 x 2048 Canon D60



vs a 3000x2000 Nikon D100



vs a 3024 x 2016 Fuji S2 Pro at 6mp



vs a 4256 x 2848 Fuji S2 Pro at 12mp



It is clear that a 4mp Foveon resolves much better then any 6mp mosaic chips, and even beats the so call Fuji "12mp".

--
jc
Sony F707
http://www.reefkeepers.org/gallery/f707
http://www.reeftec.com/gallery
 
X3 does give you true data in term of the RGB color space. Each
pixel within the Foevon chip can store the full range RGB value
between (0,0,0) to (255,255,255).
First off, the F7 sensor will report 12-bits per pixel, so the value will be in the range 0 .. 4097 for each channel. Of course so do most DSLR mosaic sensors.
So each pixel is a true RGB representation w/o any guess work.
Wow, you are claiming the X3 will be perfect? Get real; it's this kind of overstatement that turns many off of Foveon hype.

It will return 3 values per photosite based on estimates of how the absorbtion rate per depth for their doped silicon formula. The absorbtion will produce an analog voltage that must be converted to a digital value. None of these steps are perfect; for example you are completely ignoring noise. You are also ignoring any issues in color separation. What happens to a photon that is absorbed exactly halfway between two of the color layers (say green and blue.) Will it be counted as green, blue, neither, both? This was the problem that stymied other attempts to use this effect for imagers. Foveon has managed to tame it enough to make it useful - we'll just have to wait and see exactly how well.
This differences alone means Foveon resolves
better and is more sharp then mosaic sensors when we compare MP vs
MP.
I think that most people would agree that this is likely. The debate is over how will a 6MP mosaic compare to a 3.5MP X3. Personally, I think that the answer will be mixed and will depend on both the implementation details, personal perference, and the scene type.
It is clear that a 4mp Foveon resolves much better then any 6mp
mosaic chips, and even beats the so call Fuji "12mp".
Sigh. No it shows that a 2048 pixel high X3 has better resolution than a 2048 pixel high D60/D100. In other words, if the X3 sensor used had the same 2/3 aspect ratio of the other sensors, it would also be 6MP. Perhaps you missed the part where Phil says....
the chip I tested has more vertical resolution and will therefore perform better on this resolution chart.
Personally, I don't take photos of resolution targets, so I find this measurement only mildly interesting. Actual samples under varying conditions is far more interesting. (After all, a 6 MP single color sensor would whup X3 ass on this one test. However, that doesn't make an interesting camera for me.)

I've never said X3 = bad. I only comment when people grossly misstate the likely advantages or disadvantages of either.

--
Erik
 
http://www.dpreview.com/forums/read.asp?forum=1000&message=3427587
Up to this point in this age of digital technology I found that all
things being equal go with more pixels if you want to print your
pictures larger. That is the reason I have a 6mp DSLR. So my 6mp
file is 3024x2016 if I want to print a 18x12in. (Epson 1280) my
printing resolution is 168 pixel/inch.... barely acceptable. So
here is the question, the Sigma Foveon is 2268x1512 so if I want to
print 18x12in. will be at 125pixels/inch. Will the Foveon X3 CMOS
produce a much better 18X12in. print compared to the present 6mp
DSLR?
There are some samples floating around here. They probably will
give you very optimistic "preview" but never the less you can do
you tests now. And tell us the answer...
I haven't found any full resolution 2268x1512 from the Sigma
Foveon.....
Boris
http://public.fotki.com/borysd/
 
I'm still confused. There's another thread on this subject (did I
say another thread, perhaps twenty or thirty)
Like I said, I refuse to get into a discussion on about how many angels can dance on the surface of a sensor. There are simply too many variables. If all mosiac sensors were alike then Phil would not bother doing comparative testing and would just describe camera features. We'll find out about 1st gen X3 in several weeks. It may be better, it may be worse, it may be both.

If you want to get a taste how many different ways there are to do de-mosiacing, try googling "Bayer Interpolation" and reading some of the papers.

--
Erik
 

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