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Sigma SD 14

 
 
Chris Malcolm
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      01-08-2008
Alfred Molon <(E-Mail Removed)> wrote:
> In article <X9bgj.73571$(E-Mail Removed)> , david-
> http://www.velocityreviews.com/forums/(E-Mail Removed)-this-bit.nor-this-bit.co.uk says...
>> Alfred Molon wrote:
>> > In article <gC8gj.73474$(E-Mail Removed)> ,
>> > (E-Mail Removed)-this-bit.nor-this-bit.co.uk says...
>> >
>> >> The
>> >> jagged edges on straight lines are another effect.
>> >
>> > But this is not aliasing. Aliasing is caused by sampling a signal
>> > which
>> > has not properly been filtered at the Nyquist frequency and therefore
>> > the samples contain a Moir? pattern.

>>
>> Alfred, you are trying my patience. It /is/ aliasing. A Moir? pattern is
>> but one effect of aliasing, as both the article you cited and others here
>> have been trying to tell you. Yes, lack of filtering is the cause, but
>> there can be other results than Moir? patterning.
>>
>> You can think what you want, but it doesn't make it right. Sorry.

>
> See this image section (a crop of a photo taken with the Sony R1):
> http://www.ddde.de/test/img1a.png


> Full of jagged lines, which you would call aliasing. But the Sony R1
> does have an AA filter, so why would this image have aliasing?


> See the same image section with less sharpening:
> http://www.ddde.de/test/img1b.png


> Suddenly all the jagged lines are gone. Jagged lines are not aliasing -
> they are a sharpening artifact.


AA filters aren't perfect. You have to make a compromise between how
much less visible you make aliasing artefacts and how much sharp
detail you lose by doing so in images in which the effect of the
aliasing is not visually noticeable. There are images in which nobody
would say there was any aliasing present, but if you managed to shift
the camera by half a pixel and took the photograph again, you'd see
some differences in luminance in some edge details in an image flip
test of the kind astronomers use. Strictly speaking that would be an
aliasing effect, but since it's so hard to make it visually obvious
nobody is bothered trying to remove it.

In the R1 the Sony engineers have chosen to risk a little more visible
aliasing in those occasional images whose repeated frequency structure
makes it visible in order to capture a bit more sharp detail in
general.

The problem IMHO is that since very few camera reviewers understand
aliasing and the compromises necessary in a world of imperfect
engineering to remove it, if a camera reviewer happens to photograph a
textile pattern or something that brings out a Moire effect they're
liable to scream "Idiotic incompetents haven't done proper
anti-aliasing! This camera is a dud!" So I suspect that fear of
ignorant outrage in reviewers affecting sales to ignorant customers
makes some camera makers put in stronger AA filtering than is really
sensible from the point of view of a photographer interested in best
high resolution sharpness.

It's rather like the dihedral angle on aircraft wings. The more
dihedral the more stable the aircraft is and the easier it is to fly,
but the cost is that it can't be thrown about so quickly. It's a
compromise between foolproofing and performance.

That's one of the things I like about my Sony R1: more good
engineering for your money, less obeisance to marketing prejudices

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

 
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Mr. Strat
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      01-08-2008
In article <4782e15e$0$14095$(E-Mail Removed)> , Michael
Tuthill <(E-Mail Removed)> wrote:

> It's a shame that over that 41 years you seem to have developed such a
> closed mind to new technology. Sigma may not be the best company out
> there (and it's a shame that bigger company didn't pick up the x3
> sensor) and may not produce a state of the art body but anyone with an
> eye for quality images can see that the x3 doesn't produce anything
> approximating your opinion of it.


I'm not closed-minded to new technology. Hell, I switched from film to
digital. I've seen the results of Foveon technology, and it just
doesn't work.

> End of conversation for me.


We should all be so lucky...
 
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Alfred Molon
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      01-08-2008
It's all fine, but getting back to the original SD14 sample image, you
will notice that the jagged lines are not so terrible. What's impressive
instead is the level of pixel crispness and sharpness.
--

Alfred Molon
------------------------------
Olympus 50X0, 8080, E3X0, E4X0, E5X0 and E3 forum at
http://tech.groups.yahoo.com/group/MyOlympus/
http://myolympus.org/ photo sharing site
 
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Michael Tuthill
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      01-08-2008
What I believe is that one's strongly held opinion holds more credence
if they've actually handled and shot with the product for a period of
time. I shoot with both a D200 and an SD14. I know from experience
that the SD14 does not produce crummy shots unless the shooter doesn't
know what the hell they're doing. Would I trade my D200 for an SD14?
No, absolutely not. If I only shot macros would I pick the SD14 over
the D200? Yes. There's no perfect camera out there. Each has
strengths and weaknesses. To diss a camera over what one has heard or
read is totally moronic particularly when there is no general concensus
amongst the reviewers that the Sigma is crummy.

As far as marketing honesty goes, well that isn't even an issue AFAIC
as all the camera companies tend to exaggerate their claims. And there
are positive reviews out there. Do a search of the Sigma dpreview
forum and you'll find links to them.

On 2008-01-07 21:09:33 -0700, SMS <(E-Mail Removed)> said:

> You seem to believe that there is some rule that in order to make any
> comments regarding a product that you actually have to own it.
>
> The beauty of the web is that it's possible to become knowledgeable
> about products _before_ you plonk down your credit card to make a
> purchase.
>
> It'd be one thing if we were dealing with a company for a reputation
> for honesty in marketing, or if there were only positive reviews by
> professional reviewers (or even some positive reviews).
>
> Instead we have a company that has taken deceptive marketing and
> advertising to new highs, and a collection of reviews that are all
> negative.
>
> Michael Tuthill wrote:
>> And your actual experience with the camera amounts to what?
>>
>> On 2008-01-07 13:05:24 -0700, "Mr. Strat" <(E-Mail Removed)> said:
>>
>>> In article <47827b5d$0$14079$(E-Mail Removed)> , Michael
>>> Tuthill <(E-Mail Removed)> wrote:
>>>
>>>> In the end it comes down to personal preferences. If you want to bang
>>>> off a few quick shots of your kids birthday party the Sigma isn't the
>>>> best choice. If you want to take photos of the mountains or some other
>>>> idyllic scene I feel the Sigma is a great alternative. For macro
>>>> shooting the Sigma is great due to the ability to take shots sharp
>>>> enough to view at original size while maintaining sharp edge detail.
>>>
>>> In the end, it comes down to something that sucks compared to other
>>> things that don't suck.
>>>
>>> Sigma has a proven history of producing mediocre cameras and lying
>>> about their specs. Foveon technology may appear good on paper, but in
>>> practice, it just doesn't work.
>>>
>>> You can buy one of these Sigma pieces of crap if you want, but your
>>> money would be much better spent on just about any other brand name
>>> cameras.



 
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David J Taylor
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      01-08-2008
Alfred Molon wrote:
> It's all fine, but getting back to the original SD14 sample image, you
> will notice that the jagged lines are not so terrible. What's
> impressive instead is the level of pixel crispness and sharpness.


Getting back to the original question, is GBP 500 good value for a Sigma
DSLR when you can get an entry level Canon or Nikon for GBP 250 -350?

Cheers,
David


 
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nospam
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      01-08-2008
In article <(E-Mail Removed)>, Alfred
Molon <(E-Mail Removed)> wrote:

> It's all fine, but getting back to the original SD14 sample image, you
> will notice that the jagged lines are not so terrible. What's impressive
> instead is the level of pixel crispness and sharpness.


and that has more to do with the lack of an anti-alias filter and the
sharpening that's applied in sigma's raw processing than anything to do
with the sensor.

you can get the same 'crispness' with a 10-12 mpix camera and then
downsample to 2640x1760 pixels (the same size as the sigma image),
particularly using nearest neighbor for the algorithm.
 
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Mr. Strat
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      01-08-2008
In article <yYPgj.74383$(E-Mail Removed)> , David J
Taylor <(E-Mail Removed)-this-bit.nor-this-bit.co.uk> wrote:

> Getting back to the original question, is GBP 500 good value for a Sigma
> DSLR when you can get an entry level Canon or Nikon for GBP 250 -350?


The Sigma DSLR wouldn't be a good value if it came in a box of Cracker
Jacks.
 
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Mr. Strat
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      01-08-2008
In article <4783c762$0$14077$(E-Mail Removed)> , Michael
Tuthill <(E-Mail Removed)> wrote:

> What I believe is that one's strongly held opinion holds more credence
> if they've actually handled and shot with the product for a period of
> time. I shoot with both a D200 and an SD14. I know from experience
> that the SD14 does not produce crummy shots unless the shooter doesn't
> know what the hell they're doing. Would I trade my D200 for an SD14?
> No, absolutely not. If I only shot macros would I pick the SD14 over
> the D200? Yes. There's no perfect camera out there. Each has
> strengths and weaknesses. To diss a camera over what one has heard or
> read is totally moronic particularly when there is no general concensus
> amongst the reviewers that the Sigma is crummy.


Again, I don't need to step in a pile of dog crap to know that it's
something that I don't want to do. I've been in photography long enough
be able to discern good equipment from bad equipment. I've read the
reviews, read the comments by owners, seen the images, read the bogus
marketing claims...bottom line...it's a piece of crap.

> As far as marketing honesty goes, well that isn't even an issue AFAIC
> as all the camera companies tend to exaggerate their claims. And there
> are positive reviews out there. Do a search of the Sigma dpreview
> forum and you'll find links to them.


Canon and Nikon, just to pick the top two, don't use questionable math
to claim that their megapixel count is something it's not.
 
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nospam
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      01-08-2008
In article <4783c762$0$14077$(E-Mail Removed)> , Michael
Tuthill <(E-Mail Removed)> wrote:

> What I believe is that one's strongly held opinion holds more credence
> if they've actually handled and shot with the product for a period of
> time. I shoot with both a D200 and an SD14. I know from experience
> that the SD14 does not produce crummy shots unless the shooter doesn't
> know what the hell they're doing.


except that the noise, blotching, aliasing, etc. all exist in images
taken by experienced users, who presumably 'know what the hell they're
doing.' just look at sigma's web site. the photographers who took
those images were beta testing the camera and they probably know the
camera better than most people do! if it happens to them, it will no
doubt will happen to the average user.

and what about the camera lock-ups and corrupted files? is that also
the shooter's fault? even mike chaney said it was the buggiest camera
he has ever owned.

> Would I trade my D200 for an SD14?
> No, absolutely not. If I only shot macros would I pick the SD14 over
> the D200? Yes. There's no perfect camera out there. Each has
> strengths and weaknesses. To diss a camera over what one has heard or
> read is totally moronic particularly when there is no general concensus
> amongst the reviewers that the Sigma is crummy.


actually, the general consensus *is* that it's crummy. just about
every review has stated that it doesn't live up to the hype, nor does
it match, let alone surpass, the quality of cameras that cost half its
price (pre-firesale), such as the nikon d80 or canon 400d. and the
sd14 also has a very limited lens selection and slow performance and
various operational quirks, rendering it even less desirable.

the only 'positive' reviews were with a lot of caveats, such as 'if you
don't mind the minimalist design' or 'if you aren't in a hurry.'
that's like saying 'jaguar gives a smooth ride, if you don't mind
fixing the engine every weekend.'

in other words, it simply does not compete with other cameras.

> As far as marketing honesty goes, well that isn't even an issue AFAIC
> as all the camera companies tend to exaggerate their claims.


other camera companies do not lie about the number of pixels. fuji
comes close, but at least they call it a 'double pixel.' everyone else
uses the correct definition of the term 'pixel'.

sigma and foveon simply proclaim 14 megapixels, which is flat out
*wrong* and the various white papers from foveon are a sea of
half-truths, along with some factually incorrect statements. in fact,
they even contradict themselves as to the meaning of 'pixel.' as i've
said before, it's arguably fraud, and i'm surprised they haven't been
called on it.

> And there
> are positive reviews out there. Do a search of the Sigma dpreview
> forum and you'll find links to them.


very very few (i.e. one, maybe two) and the positive comments are very
carefully phrased, compared to quite a few negative reviews (over a
dozen, last i've counted).
 
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Peter Stavrakoglou
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      01-08-2008
"nospam" <(E-Mail Removed)> wrote in message
news:070120081653140634%(E-Mail Removed)...

> indeed it was grossly overpriced, which is why it dropped $400 (25%)
> just three months after its introduction. however, it appears that the
> recent liquidation sale is over, as amazon now shows the lowest price
> to be $1139.


Get your facts right. The SD14 did not sell for $ 400.00. The lowest price
was $ 649.99.


 
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