Fovean Sensors

BustedFrog wrote:

There is nothing wrong with the way they describe the chip's pixel count.

That is as long as there would be nothing wrong with a car manufacturer
releasing a model with a dashboard clock running at half the rate of a
conventional clock and claiming that their car was twice as fast when
compared to other cars, because it could cover the same distance in half
the time.

Unless they make a point of how their chip is different and how they are
assessing the capabilities of their chip,

-- which they do --

they are being dishonest,
there is no other way to regard what they are doing.

Better automotive analogies would be the well-known problems assessing
how to describe the engine cylinder capacity for performance
comparison purposes of cars which don't use the conventional
four-stroke cycle, or which don't even have cyclinders. In those cases
there have been disputes just as endlessly complicated as the Foveon
pixel count dispute.

--
Chris Malcolm DoD #205
IPAB, Informatics, JCMB, King's Buildings, Edinburgh, EH9 3JZ, UK
[http://www.dai.ed.ac.uk/homes/cam/]

Ray Fischer wrote:
2SQUID wrote:
Ray Fischer wrote:
2SQUID wrote:
Ray Fischer wrote:
2SQUID wrote:
Ray Fischer wrote:
measekite boyhowdy wrote:
Ray Fischer wrote:
The problem is that Sigma has a reputation of dishonesty
Explain what you mean about a reputation of dishonesty.
They are liars.

As long as they continue to be brazen liars then I will continue to
heap scorn and criticism upon them.
What do you mean abouit brazen liars. Can you cite some examples.
Yes. They call the SD14 a 12MP camera when it's really only a 3.5MP
camera.
But that's only your opinion Ray.
No, it is not just my opinion.

Measekite asked you cite some evidence
No, moron, he asked for an EXAMPLE.

Given your limited ability to read I'm not surprised to see that
you believe that Sigma is telling the truth.

The bit you overlook is that a Sigma SD14 image is sharper and clearer
than a 10 or 12 Mp image from a Bayer sensor
Where's your evidence? I say you're full of ****.

Surprise, surprise, the SD14 image actually enlarges (Interpolates) to
larger sizes
I can do the same to ANY image using Photoshop. So what?

and with more sharpness and less blurred detail than those
from a 10 or 12 Mp bayer sensor.

Bull****.

Megapixel was invented to measure flat, single layer sensors.
Bull****. The word "pixel" goes back some decades and describes a
single picture element. A single dot in an image. The number of bits
used to represent it is wholly irrelevant.

The thing photographers should be looking at instead or arguing about
irrelevant issues like you are, is the quality of photographs a camera
can produce when printed at the calculated size of the sensor.
Then why does Sigma lie about their cameras? Because the tests that
have been done show it to be equivalent to a 7mp camera?

Sad thing Ray, that you try to score points by insulting those who have
Listen, asshole: When oyu start LYING to me then I take offense.
Don't like it? Don't lie.
How did you know my name?

So tell us the size (measurement) of a pixel Ray.
A pixel is a point.

A couple of decades ago eh? Hmm lets see now. Judging by your language
and immature responses I'd say that was before you were born.
You're just whining that you got caught lying in order to support a
position you don't even understand.

So come on Ray... Sigma Photo just offered me a full size image from a
SD14.
So what? Most of the camera makers do the same.

I already have a 40D Canon and 1:1.5 macro set-up.
LOL! You didn't even spend your own money on one!

I think that that says everything that we need to know.
Showing your yellow streak Ray?

Like the way you ran away from my request that you provide EVIDENCE
for YOUR claims, hypocrite? YOU claimed that an SD14 is sharper than
a 12MP Canon 40D. Where's your evidence?

Missing.


Weren't you the one who failed to come up with a file? The challenge was
after all that you provide a Canon file and I'll supply the SD14 file.

What happened? Chicken out?

Ray Fischer wrote:


I did and they sent me some very nice raw files.

How do you know that they weren't altered?

When I processed them in Sigma's converter, they run rings around those
converted with Adobe ACR.


Actually I have no knowledge of the files Sigma sent me having been
altered or not altered but the images I got from a fellow Sigma owner
(Who also owns a Canon 5D) are absolutely guaranteed not have been
altered. It is one of these I used for the exercise in processing.

If you hadn't been so lily livered and actually coughed up an image to
compare, like I asked you to, you'd see first hand the difference. As it
is, all we have from you is a load of foul mouthed accusations.

Tell me Ray, does it give you a hard on to keep using the word liar?
Water off a ducks back when you try it on me because very clearly you
have not a clue about the person you so frequently try to insult. Pity
it has no effect. Why don't you try a different approach? It couldn't
have any less effect, now could it?

Chris Malcolm wrote:
BustedFrog wrote:

There is nothing wrong with the way they describe the chip's pixel count.

That is as long as there would be nothing wrong with a car manufacturer
releasing a model with a dashboard clock running at half the rate of a
conventional clock and claiming that their car was twice as fast when
compared to other cars, because it could cover the same distance in half
the time.

Unless they make a point of how their chip is different and how they are
assessing the capabilities of their chip,

-- which they do --

they are being dishonest,
there is no other way to regard what they are doing.

Better automotive analogies would be the well-known problems assessing
how to describe the engine cylinder capacity for performance
comparison purposes of cars which don't use the conventional
four-stroke cycle, or which don't even have cyclinders. In those cases
there have been disputes just as endlessly complicated as the Foveon
pixel count dispute.


I guess as long as there are those who do things differently, there will
always be those who try to force rules of measurement on the different
people. I like the comparison with to Wankle engines. It is a typical
scenario when American engine makers altering the measurement method to
suit their own purpose and it actually backfired on them.

In article , Mark Thomas
wrote:

Just out of interest, I have sent an email to Sigma asking if they wish
to comment on the painted-out-background-on-sample-images issue. I'll
let you know if they reply.

it'll be interesting to know what they say.

In article , 2SQUID
wrote:

Sigma's web site is probably not the best place to look for
representative examples of what a Sigma camera does, any more than
Canon's site is the best place to look for representative examples of a
Canon image. While on the subject of Canon.

How come you haven't mentioned Canon having touched up images for
display? They do it too you know and in fact got "caught out" as you put
it doing it to clean up 20D images for display.

which images and how were they touched up? if canon got caught, then
where can one read about it?

It is a widely know fact that no RGB devise can produce pure black. The
black information is carried in the green channel and all 3 colours
mixed to make a "video" black.

uh, sure.

Maybe the background of Sigma's image had
someone or something in it they needed to be removed?

like noise or blotches? if something was removed, then it was
manipulated. you're catching on.

Is there any
evidence they altered the subject? NO!

sigma didn't alter it, the photographer did. it's her style and she
has many images with a pure black background and some with pure white.
there's nothing wrong with that, but it's not a representative sample
of what the *camera* can do in normal use.

In article , 2SQUID
wrote:

Better automotive analogies would be the well-known problems assessing
how to describe the engine cylinder capacity for performance
comparison purposes of cars which don't use the conventional
four-stroke cycle, or which don't even have cyclinders. In those cases
there have been disputes just as endlessly complicated as the Foveon
pixel count dispute.

I guess as long as there are those who do things differently, there will
always be those who try to force rules of measurement on the different
people. I like the comparison with to Wankle engines. It is a typical
scenario when American engine makers altering the measurement method to
suit their own purpose and it actually backfired on them.

so, what measurement method did they use, if not displacement and
horsepower?

2SQUID wrote:
nospam wrote:
In article , measekite
wrote:

1. The Bayer camp
What is the Bayer camp? Does it include CCD and CMOS?

both

2. That unlike the Bayer cameras, the Sigma does very little
"in-camera" processing and relies substantially on a 'real'
computer running Sigma's own Photo Pro software to finalise the image.
If that is the case is this Sigma software operating system
dependent. By that I mean only Windows and Mac. If that is the
case then the camera is a poor choice and a very expensive choice.

most camera companies only provide mac and windows software, and sigma
is no exception. however, for linux and other platforms, dcraw can be
used for sd9/10/14, but it has not been updated for the dp1 (and
probably won't any time soon).

DC RAW is worse than Adobe Camera raw on Sigma images. Either you use
the Sigma software or put up with poor quality de-mosaicing and the
inevitable whining from those who refuse to use the only program that
does it properly.

And that means you cannot rely on a Linux system if you want Sigma.
That means more than maintaining $1,000 of Windows software or Mac
software. I would rather get fine images from (Canon or Nikon) my
choice or some other mainstream camera and spend that $1,000 on a couple
of lenses.

2SQUID wrote:
measekite wrote:
Everything said is nice and the argument appears to be a moot point.

Sigma is claiming their new technology is able to produce better
color resulting in a higher quality print. It does not make a
difference if it is a 1MP or a 20MP camera. It is the results that
count.

So the real question that everybody is skirting in place of pixel
count or numerical resolution is does this technology produce
significantly better color that results in a groundbreaking better
printing photograph other things like ink and paper set aside to
warrant an industrial shift to a different technology? That is what
this discussion should be about. That is what at least I am
interested in finding out.

According to Sigma the answer is yes. So if that is the case then
you would expect deep pockets Canon or even well healed Nikon to be
doing research along those lines and you may have read (leaks to the
press) about something in that direction by know. There has been no
mention of that to my knowledge.


And why would anyone want to try and develop someone else's product
that has iron tight patents to it? Why do you thing it has taken Nikon
so long to come up with a CMOS sensor?

For that matter, how come no one is doing any development on Fuji's
ground breaking "dual sensor" technology? Same reason. Fuji have iron
clad patents.
Because many times there is another way of getting similar results and
sometimes that method is even better.

2SQUID writes:

The SD9/10 resolve as well or better than any other 3.5 MP Bayer camera,
but they're not at all comparable to a 10 MP or 14 MP Bayer camera in
real resolution.

Is this from your personal experience Dave? It doesn't sound like it.

I don't own one of the SD cameras. But my opinion is based on examining
a number of full-size images posted by Sigma owners, and the sample
images on the dpreview pages.

I put this page together an hour or so ago:
http://www.auspub.com.au/squids/SD14.htm

There's very little to look at in the 100% scale image, but the fine
hair detail is a mess. Individual strands show bad "staircase"
artifacts at some angles. Now, have you tried comparing this to the
image from a 10 MP Bayer camera resized down to match the Sigma's image
size?

You might not agree with my opinion or that I believe a "real"
photographer needs to separate themselves from everything except the
photography but this quick and dirty exercise proves 3 things to me.

1. The Bayer camp have done a fine job of fooling people for far too
long. Many 10 and 12 megapixel cameras produce absolutely shocking
images that need an on-board computer to patch up their images before
saving them as some engineers idea of a RAW file.

You have said nothing about what you mean by "shocking", so I'll ignore
that as content-free. Similarly, both Bayer and Sigma cameras store
"some engineers idea of a RAW file", so that's content-free too. In
fact, you don't describe what "patch up" means, so the entire paragraph
is pointless.

2. The Sigma SD14 is every bit the equal to a 10 or 12 megapixel Bayer
image in sharpness and clarity when de-mosaiced to the same size using
Sigma's own Photo Pro software.

Equal in what way? The Sigma image may *look* sharp, but examination
of the resolution test images and real photographs show plenty of
artifacts and less resolution for real fine detail. Now, for some
subject matter, the Sigma actually produces better images overall at
the same number of megapixels. But comparing a 3.5 MP Sigma to a 10 or
12 MP Bayer, the Sigma just always loses, unless you really like the
sort of image mistakes it makes. (And you can get most of those by
downsampling using nearest neighbor in Photoshop; you don't need a Sigma
camera for that effect).

2. That unlike the Bayer cameras, the Sigma does very little "in-camera"
processing and relies substantially on a 'real' computer running Sigma's
own Photo Pro software to finalise the image.

If you want, you can have Bayer cameras write raw data and do the
processing on a host computer too. It does give more control. The
difference is that the Bayer cameras can *also* produce decent JPEGs, or
both RAW and JPEG at the same time if that works better for you. I
don't know if this is because Sigma can't afford a decent signal
processor for the camera, or their algorithms are just too expensive to
run in any available processor, but this is definitely a place where the
Sigma cameras lose to all of the competition.

I also believe that before any meaningful discussion of the resolution
of different types of sensors can be had, we really do need to recognise
that a Bayer sensor absolutely need three times the number of pick-up
sites, just to capture the same colour information as a Foveon sensor
does. This results in the Bayer camp accusing Foveon of fobbing the figures.

First, the colour response of the Foveon sensors is notoriously bad,
because the three channels are not as spectrally independent of each
other as they ought to be (and not compared to Bayer sensor filters).
So the colour transforms involve a lot of cancellation, which boosts
noise. And the cameras are also notorious for blotchy colour and yellow
casts. So Foveon colour is nothing to aspire to.

Second, even in a theoretically perfect world, the real advantage of
sensing colour at every pixel is that it gives you colour-difference
resolution that matches luma resolution. This is nice if you can get
it, but not really necessary for pictorial photography since the human
eye's resolution for colour-only difference is *one tenth* of its
B&W resolution. Bayer sensors effectively have a colour resolution that
is half their luminance resolution - which is better than it needs to be
to satisfy the eye in prints where the luminance seems acceptably sharp.
So the Foveon's colour resolution advantage isn't as significant as it
might seem.

I also make a guess that most of the knockers of the SD14 have never
held one in their hand, much less spent any time using one. I used a
handed down SD10 for several years while I was doing my studies. I got
pasted by everyone and sundry until they saw the life size portraits it
took and the 36" wide seascapes I made from it's images. You simply
couldn't do this if it were resolving to 4 mega pixels.

Handwave all you want, but the sensor physically has only 2268x1512
light-measuring locations.

Your experience is evidence that you can produce pretty good images of
certain subjects with less than 4 MP - because that's all the camera
does have. On the other hand, the image from a 12 MP Bayer camera
downsampled to 4 MP using a decent algorithm will *also* look pretty
good, without the Sigma's artifacts. And if you leave the Bayer image
at 12 MP, it can look even better.

There seems to be a collision going on between photographers and
technocrats that never existed in the days of film. I can't find any
discussion like this about the resolution of film, the way there is in
how a manufacturer measures their camera's resolution.

As I remember it, even in the days when everyone used film, there were
those who liked films with coarse but very sharp grain, and those who
liked finer but "mushier" grain. And there was some controversy about
how to measure resolution. And video cameras didn't look like film
cameras.

Sigma SD14 cameras are on an equal par with any 10 or 12 megapixel Bayer
or CCD sensor. And I'll add this in parting. Backlit subjects are a
Bayer's worst nightmare and a Foveon's playground for exciting images.

It seems to be a matter of preference. Some people look at Sigma images
and think they're beautiful, other photographers look and say "yuck".
Sometimes even when both are looking at the same image.

But, objectively looking at tests, it's clear that (a) Foveon sensors
are not competitive in resolution due to low pixel count, (b) the lack
of an anti-aliasing filter results in various image artifacts in fine
detail. You may *like* the images anyway, but not everyone does.

Dave