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Sigma Digital SLR Cameras.



 
 
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  #21  
Old June 27th 04, 01:16 AM
Steven M. Scharf
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Default Sigma Digital SLR Cameras.

"Phil Wheeler" wrote in message
...

Georgette Preddy wrote:


I don't know of anyone who knows anything about digital who shoots
above the lowest ISO setting.


Which simply proves that you know no one who knows anything about
digital. We already have concluded that you are in that category,

Giorgio.

Notice the implicature in GP's statement. Advertisers will often go the
"play dumb" route, with statements like: "we know of no other product as
good as ours."

With the Sigma SLRs you'd better not try to shoot at higher ISOs. It's one
reason that the Sigma SLRs are solidly in the sub-amateur category, EXCEPT,
for landscapes and studio portraits. No one would buy one for any sort of
action photography or low light photographt, where higher ISO settings are
necessary.

GP knows no one who knows anything about digital--including himself.


  #22  
Old June 27th 04, 04:43 AM
Steven M. Scharf
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Default Sigma Digital SLR Cameras.


wrote in message
...
In message ,
(Georgette Preddy) wrote:

http://www.outbackphoto.com/artofraw/raw_05/essay.html

Why does the vertical chart (horizontal resolution) fail to resolve at
all with the SD9? I see noise more than I see lines.


That link is not a very convincing sell for Sigma! They show that it is
possible to fool a Bayer sensor, but the Sigma images are worse that the
Bayer images.


  #23  
Old June 27th 04, 01:52 PM
Bart van der Wolf
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Default Sigma Digital SLR Cameras.


"Laurence Matson" wrote in message
m...
SNIP
Well, if non-delivery pertains to poor character, then I guess he is
sharing good company with dear Steven, who claims the SD10 only has
3.34 MP of resolution. Whether this is true or not could be cleared up
quickly if he will just nominate whatever image from a 3.5 MP CFA
camera he wants.


I'm not sure whether you really don't understand how meaningless such a
comparison is, or that you hope someone else is that stupid. Bayer CFA
sensors are (almost without exception) fitted with anti-aliasing filters
that reduce the modulation of the finest details, to avoid the inevitable
aliasing of any regularly sampled (high spatial frequency) signal. Comparing
that to an unfiltered image for resolution is nonsensical.

Also your 'suggestion' that the SD-10 has more than the resolution allowed
by the Nyquist limit is ludicrous. A sampling system *cannot* exceed the
Nyquist frequency without adding aliasing to the signal, often at a higher
modulation than the original signal. You are almost certainly looking at
lower frequency aliases that mimick some sort of fake detail.

Bart

  #24  
Old June 27th 04, 05:44 PM
Steven M. Scharf
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Default Sigma Digital SLR Cameras.


"Bart van der Wolf" wrote in message
...

"Laurence Matson" wrote in message
m...
SNIP
Well, if non-delivery pertains to poor character, then I guess he is
sharing good company with dear Steven, who claims the SD10 only has
3.34 MP of resolution. Whether this is true or not could be cleared up
quickly if he will just nominate whatever image from a 3.5 MP CFA
camera he wants.


I'm not sure whether you really don't understand how meaningless such a
comparison is, or that you hope someone else is that stupid.


I'm fairly certain that it's the latter. GP understands more than he lets on
in his posts.


  #25  
Old June 27th 04, 06:19 PM
Phil Wheeler
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Default Sigma Digital SLR Cameras.



Steven M. Scharf wrote:


I'm not sure whether you really don't understand how meaningless such a
comparison is, or that you hope someone else is that stupid.



I'm fairly certain that it's the latter. GP understands more than he lets on
in his posts.


He'd have to or he would not be able to operate a computer :-)

Phil

  #26  
Old June 27th 04, 06:22 PM
Laurence Matson
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Default Sigma Digital SLR Cameras.

Lionel wrote in message . ..
Kibo informs me that (Laurence Matson) stated that:

Well, if non-delivery pertains to poor character, then I guess he is
sharing good company with dear Steven, who claims the SD10 only has
3.34 MP of resolution.


Which is 100% correct. The *fact* is that its sensor has 3.34 million
pixels of resolution. This has been pointed out to you innumerable
times, yet you keep on coming up with increasingly silly arguments in an
attempt to justify your belief that this is not the case.
OTOH, you are welcome to claim that the 3.34 million Foveon sensor
pixels are *superior in quality* to the equivalent number of
Canon/Nikon/Fuji pixels, & I (& others here) might well agree with you,
particularly in terms of chroma detail.
However, in terms of resolution (digital resolution, not optical
resolution, which is a separate issue again), a pixel is a pixel is a
pixel, & pixel resolution is simply the number of pixels in a row,
multiplied by the number of pixels in each column. Each of those pixels
could be luma only, RGB (eg; Foveon), CFA (eg; Bayer) or even more
exotic varieties, but none of that relates to the resolution of the
sensor array, only to the colour depth or *quality* of that pixel.


Lionel, oh patient one,

I am not sure where I said much about resolution - yet. What I tried
to point out - and I believe it was you who really helped out - is
that Foveon could have a legitimate case on the pixel count. Given
that a pixel is the smallest part of an image and each of the sensors
collects information which contributes to the final image, each is
called a pixel. No doubt about that in my mind.

However, if you want to go straight to the resolution issue, fine.
Just nominate a 3.5 or so MP image (preferably from a DSLR; therefore
we'll settle for a D30 image), and we'll take it from there. We might
want to explore how you are defining resolution relating to pixels;
then again, I suspect you might not. However, the 3 MP image would be
a good starting point.
  #27  
Old June 27th 04, 06:47 PM
Laurence Matson
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Default Sigma Digital SLR Cameras.

"Steven M. Scharf" wrote in message hlink.net...
"Lionel" wrote in message
...
Kibo informs me that (Laurence Matson) stated that:

Well, if non-delivery pertains to poor character, then I guess he is
sharing good company with dear Steven, who claims the SD10 only has
3.34 MP of resolution.


Which is 100% correct. The *fact* is that its sensor has 3.34 million
pixels of resolution. This has been pointed out to you innumerable
times, yet you keep on coming up with increasingly silly arguments in an
attempt to justify your belief that this is not the case.


3.43 actually.

See "http://sigmaphoto.com/html/Cameras_sd9.htm." Sigma hasn't yet fully
applied their new math to the SD9 page, and they still distinguish between
photodetectors and pixels.

It's not me that claims that the Foveon sensor is 3.43 megapixels, this is
an incontravertible fact, that even Sigma and Foveon admitted, until very
recently. I don't care if LM/GP/OW/SG/SQ/DG wants to assert that 10.29
megaphotodetectors are more than 6 megaphotodetectors, just as long as they
don't mislead people by equating a pixel and a photodetector.

LM/GP/OW/SG/SQ/DG also keeps claiming that Sigma is tha largest lens
manufacturer in the world, something that even Sigma is careful to avoid
claiming. Sigma accurately states: "As the world's largest independent
manufacturer of zoom and fixed focal length lenses... ." The qualifier of
"independent" is key, since they manufacture less lenses than Canon or
Nikon, but Nikon and Canon only manufacture lenses for their own lens
mounts. It wasn't until I saw the virtual identical wording in posts from
LM and GP, that I realized that they were likely one in the same.

Hard to understand the agenda of LM/GP/OW/SG/SQ/DG. Certainly they haven't
been successful in misleading anyone on rec.photo.digital, despite their
best efforts.


Steven,

I gotta hand it to you. You sure know how to dodge the issue. For the
moment, I couldn't care less what the pixel count is on the Foveon
sensor. For the moment, I'll accept your statement that it is 3.34 MP.
What I am disputing - here comes the point so please pay attention -
is your claim that it only has the resolution of a 3.34 MP camera.

To quote:

"it's an image with a resolution of 3.4 megapixels"

I don't want to go into any of your other nonsense now ("No upgrade
path"; got any plans for Photokina 2004?). Just this: If this camera
has only 3.34 MP of effective pixels producing resolution, then let's
see how it stacks up against the competition.

On another note: If you are so linguistically stupid that you cannot
tell one writer apart from another, then perhaps you should read a
little. Literature! I am not the same person as the others on your
list. And my agenda is rather short at the moment (see above). If you
are still over-loaded by that, fine. We can move on to another issue
on your "site" (I just love the list of great authoritative
references; boy, I guess that settles that: You sure know how to
Google! Well done, Steven!)

Oh, and I noticed that you are a Nat Semi shareholder. Great. Welcome
aboard.
  #28  
Old June 27th 04, 07:02 PM
Laurence Matson
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Default Sigma Digital SLR Cameras.

John McWilliams wrote in message news:OhWCc.116181$0y.112976@attbi_s03...
Laurence Matson wrote:

John McWilliams wrote in message news:BJhCc.96372$Sw.89183@attbi_s51...


You left out an important bit...
" He, the imposter/Troll/whatever "Mr. Preddy" believes that:
The current implementation of the Foveon chip is superior to all other chip
technologies.



John,

I am not sure that "Preddy" is really going out on a limb with a claim
like that. In terms of technology, there are a lot of people -
including many inside Canon and Sony - who believe the *technology* is
superior. Whether the current implementation is superior is something
one could debate about.

That's been "debated" to death. Only you and GP claim a ~3.3 MP Foveon
chip gives results as good as a ~6.3 MP Nikon or Canon.


Oh really. Apparently you limit your reading to Classics Illustrated
and The National Enquirer. Ever read this:

"What's clear to see from these comparisons is that the X3 sensor
technology achieves amazing levels of detail and resolution pixel per
pixel compared to the six megapixel sensor of the EOS 10D. Indeed it's
fair to say that the EOS 10D doesn't truly exhibit any more visible
detail than the SD10 (just a larger image, which we'll examine more on
the next pages). Tone and color wise I preferred the EOS 10D's output,
although it's worth remembering that the EOS 10D's internal processing
systems have tweaked the tone, color and sharpness of the image, the
SD10 image is 'Default'. We managed to produce a much better SD10
image with some subtle parameter changes in Photo Pro 2.0 (see
below)."

From this:

http://www.dpreview.com/reviews/sigmasd10/page15.asp

Of course, he doesn't know what he's talking about. So let's compare.
Obviously the Foveon sensor is only 3.34 MP (according your resident
authority, Dr. Steven). Therefore, nominate an image and let's take it
from there. Remember, play fair! You may only nominate a ca. 3 MP
image.

I'd be happy to test out any new Foveon based dSLR when one is made
whose end product is as good as or better than prosumer cameras from the
Bayer tech. folks.


I'm sure you would. The last I checked, however, your name was just
above Steven's (and below Ken Rockwell, can you believe that?) on the
list for test cameras. However, I will put in a good word for you.
With your open mind it should be no problem.

Moreover, "Mr." "Preddy" has claimed to be a photographer (pro!), but
cannot bring himself to post a single picture with EXIF info that he
shot himself, in spite of repeated requests and challenges to do so.



Well, if non-delivery pertains to poor character, then I guess he is
sharing good company with dear Steven, who claims the SD10 only has
3.34 MP of resolution.


But that's exactly what it has! Kill the Marketing Dept.!


Great! Then let's make a little comparison and PROVE you are right.

Please don't bring another into this conversation. He's more than able
to join if he wishes, and I do believe that it's clear my non-delivery
clause relates to "GP"'s inability to make images and post them.


Well in my mind, non-delivery also relates to not delivering the goods
to support your argument. If this is so clear, why the waffling? Are
you Belgian? After all, you cannot accuse me of not delivery plenty of
images for you to tear apart. They are all over the Web and on display
in New York, California, Japan and soon in Germany.
  #29  
Old June 27th 04, 07:10 PM
Laurence Matson
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Default Sigma Digital SLR Cameras.

John McWilliams wrote in message news:9c3Dc.155920$3x.65592@attbi_s54...
MarkH wrote:

John McWilliams wrote in
news:OhWCc.116181$0y.112976@attbi s03:


That's been "debated" to death. Only you and GP claim a ~3.3 MP Foveon
chip gives results as good as a ~6.3 MP Nikon or Canon.



Actually I have seen numerous claims by the idiot Preddy that the 3.43

MPix
Foveon blow away the 11.1 MPix Canon 1Ds. Obviously claims like

that
make it easy to see that anything GP claims can be taken with a grain o

f
salt.

On the review at dpreview.com for the Sigma SD10 the comparison to the


Canon 10D suggests that the resolution is about the same between the tw

o.
Obviously when each sensor only senses one of the three colours, then t

he
data is interpolated, there must be some loss of resolution compared to


sampling 3 times the data at each location. GPs contention that the Si

gma
is vastly superior is not at all supported by this review, the review s

ays
that they are very close in image detail.

However when the Sigma SD-10 is compared to the Canon 10D and all facto

rs
are considered - dpreview agrees with me that the Canon is the better
choice. If some Sigma lenses are so good that they have no equal in an

y
other brand, then OK I can buy them for my 10D, I don t need a Sigma

camera
to use Sigma lenses. But the Sigma SD-10 is very limited on what lense

s
are available for it to use. At higher ISO I think that my 10D is also

way
better than the Sigma.

I don't think more than 4 people would disagree with what you say here.
It's too bad there's been so much chaff to cut through, and I do hope
the foveon chip makes it over the long haul.


John,

You are obviously one of the four:

"That's been "debated" to death. Only you and GP claim a ~3.3 MP Foveon
chip gives results as good as a ~6.3 MP Nikon or Canon."
John McWilliams

So what is the deal?
  #30  
Old June 27th 04, 07:18 PM
Laurence Matson
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Default Sigma Digital SLR Cameras.

wrote in message . ..
In message ,
(Laurence Matson) wrote:

I am not sure that "Preddy" is really going out on a limb with a claim
like that. In terms of technology, there are a lot of people -
including many inside Canon and Sony - who believe the *technology* is
superior. Whether the current implementation is superior is something
one could debate about.


So, now you are starting to admit that there are problems with the
current Foveon sensor. That's a measure of progress, but just remember
that most of the emotion you saw from Foveon nay-sayers when you
appeared here had to do with your assertion that the current Foveon was
superior technology (and your fore-runners here, like "George Preddy"
and Guido V.).


John,

I am not sure about your command of the English language. Is it not
your mother tongue? Do you need a translation?

Being willing to debate about something is not saying that the issue
to be debated is good or bad. It is only expressing a willingness to
debate the issue.

And do you have any idea who Guido really is?


At the end of the day, the current X3 does not have very accurate color;


Says you!

it only has higher resolution per pixel of certain color pairs than the
Bayers. The extra sharpness is due more to aliasing than real
sharpness, due to a lack of proper alias filtering in the Sigma cameras.


Not quite right.

Not even the most vehement Foveon detractor here would argue that full
RGB at each pixel would not be better than a CFA capture, all other
things being equal. They are not equal. The better Bayer DSLRs have
more accurate color than the X3; just at a lower resolution.


Do I need to dish up another group of images to show what nonsense
this statement is?

The
AA-filtered bayer images, even though they tend to be soft out of the
camera, are much better at giving information about where points of
light and edges are actually located in an image, with sub-pixel
precision. The Sigmas snap everything in sharp focus to a grid of
inaccurate sharpness, and often doubles things that are almost that
sharp (the hollow hairs and such that you often see).

 




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