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DXOmark tested the D3X - comparison to 5DMKII and 1DsMKIII

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what did you think was misrepresented ?
neroangelo said:
if the DXO tests are correct isn't that false advertising and
misrepresentation? Wouldn't people be suing Canon and Nikon for this?

--
Slainte (cheers)

You cannot depend on your eyes when your imagination is out of focus.
:- Mark Twain
Click to expand...
 
Well if the DXO test is the 'right' example then hasn't the manufacturer made a false statement and promise as to what the camera can deliver?

--
Slainte (cheers)

You cannot depend on your eyes when your imagination is out of focus. :- Mark Twain
 
oh sorry, you mean about the sensor ?

I guess Nikon can claim they took the sensor from sony but then changed any small detail of the specification of it
technically they could then say its not the one in the a900.

They might well have mucked around with it, and even improved it.

but the word on the street (I think actually admitted by Nikon recently) is that it was sony "technology". It can be no coincidence that the pixel count is identical, nor the curve similarity in DXO.

BTW I don't think the DXO test are anything definitive. They are just another source of info.

If I was a Nikonian i would wait for the D700x, or, alternatively, consider the A900 with the 24-70mm zeiss lens. looks pretty cool
neroangelo said:
Well if the DXO test is the 'right' example then hasn't the
manufacturer made a false statement and promise as to what the camera
can deliver?

--
Slainte (cheers)

You cannot depend on your eyes when your imagination is out of focus.
:- Mark Twain
Click to expand...
 
Looking over the results if there even correct seems to me the only real world differance you might see in actual prints is the extra dynamic range of the D3X. All the other results i doubt very much if you would see any real world differance in prints. Hopefuly Canon will concentrate more on dynmac range on there next round of sensors.
--
http://www.pbase.com/dc9mm

 
thw said:
thw said:
DxO tests the sensor only and shows what the camera is capable of.
Other tests include variables such as lens quality and (software)
postprocessing.
Click to expand...
True. But even within the same platform (e.g. comparing Canon to
Canon, or Nikon to Nikon) and using the same lens, the ISO ratings as
indicated by DXO are still weird. Another example: in comparing the
D90 against the D300, are we saying Nikon has suddenly forgotten how
to produce decent jpeg on the D90 at ISO 3200 even though DXO results
seem to indicate superb performance (as good as 1d3)? Why this
discrepancy?
Click to expand...
DxO says nothing about jpeg engine, it's only a RAW test. Good jpeg is not so easy in-camera, check both Sony and, recently, Canon performance. The in-camera converter has to be very well designed and made of highQ parts, which likely are not at same level in the D90.

One should be able to read the test carefully, including checking all aspects, behaviour as ISo increases, etc.

The D3x is clearly optimized for low ISO, but pretty good even as ISo goes up.

--
Renato.
http://www.flickr.com/photos/rhlpedrosa/
OnExposure member
http://www.onexposure.net/

Good shooting and good luck
(after Ed Murrow)
 
thw said:
And this is another weird thing. REAL test results (for example,
those conducted by Phil) show the opposite is true.

I have a hard time trying to reconcile DXO results with real world
testing by Phil and many other reviewers.
Click to expand...
The discrepancy between DxO's results and the manufacturer's ISOs is very straightforward to explain, and it's all down to how metering and exposure works.

Basically the conflict is between two ways of measuring ISO. One method is to determine the exposure required such that, if you spot meter off an 18% grey card and then take a picture of it, the grey is rendered at a luminance of 50% in the resultant image file. I'd argue this is the method most relevant to how the majority of photographers work, and if you test cameras this way they will all give essentially the same answer (always bearing in mind that ISO 12232 allows a tolerance of 1/3 stop either way, probably as much to cater for manufacturing variations as anything else).

However DxO use a different method, which is based on the point where highlights clip to white. This does not necessarily give the same answer as the grey-point method due to tone curve differences between cameras, and the difference between the two methods generates the discrepancy in DxO's results. In fact it turns out that the difference actually reflects the highlight dynamic range of the camera; the lower DxO's "true" ISO, the more higlight DR you've got.

Perhaps the easiest way to consider this is to think in terms of taking two images of a high dynamic-range scene, using identical shutter speeds and apertures but with and without Highlight Tone Priority turned on. Visually, both will be correctly exposed, and by the grey card test, both shot at the same ISO. But the highlight clipping point will be shifted by a stop between the two, and therefore using that definition they will have been shot at ISOs one stop apart, with an ISO 200 HTP shot considered to be ISO 100.

Now this doesn't actually mean DxO's method is wrong, as they are only concerned with RAW data not output image files, indeed it's the only way they can compare RAW output on an equal footing. But it's purely about technical comparison of RAW data, not about using the camera.

--
Andy Westlake
dpreview.com/lensreviews
 
thw said:
thw said:
Everyone knows 5DMk2 DR is better in than D700.
Click to expand...
the evidence this is based on?

I am asking because I find DXO results VERY questionable. For
example, they claim the D90 sensor is as good as the one in the 1D3.
YET, Phil's tests, albeit based on jpeg, show the D90 sensor is not
any better than the D300:
Click to expand...
Tests based on jpeg only benefit jpeg shooters. People trash Ken Rockwell when he makes a claim based on his jpeg tests. 'Controlled' jpeg tests actually doesn't make much difference. DxO result should be taken seriously by those who do more to their files (i.e. RAW shooters).

Max
 
Andy thank you for your answer.

This is an interesting issue. I choose 4 cameras from Nikon and Canon

DxO says gives these values for dynamic range (in order of the best):
Nikon D700 - 12,2
Nikon D3 - 12,2
Canon 1Ds III-12
Nikon D300 - 12

dpreview gives (in order of the best):
Nikon D300 - 8,8
Nikon D3 - 8,6
Canon 1DsIII -8,6
Nikon D700 - 7,8

I understand that there are 2 different types of tests ... but the results are totally different.

Off the topic:
Andy, how is the test from Canon 5DII doing? Is it in working?
Andy Westlake said:
thw said:
And this is another weird thing. REAL test results (for example,
those conducted by Phil) show the opposite is true.

I have a hard time trying to reconcile DXO results with real world
testing by Phil and many other reviewers.
Click to expand...
The discrepancy between DxO's results and the manufacturer's ISOs is
very straightforward to explain, and it's all down to how metering
and exposure works.

Basically the conflict is between two ways of measuring ISO. One
method is to determine the exposure required such that, if you spot
meter off an 18% grey card and then take a picture of it, the grey is
rendered at a luminance of 50% in the resultant image file. I'd argue
this is the method most relevant to how the majority of photographers
work, and if you test cameras this way they will all give essentially
the same answer (always bearing in mind that ISO 12232 allows a
tolerance of 1/3 stop either way, probably as much to cater for
manufacturing variations as anything else).

However DxO use a different method, which is based on the point where
highlights clip to white. This does not necessarily give the same
answer as the grey-point method due to tone curve differences between
cameras, and the difference between the two methods generates the
discrepancy in DxO's results. In fact it turns out that the
difference actually reflects the highlight dynamic range of the
camera; the lower DxO's "true" ISO, the more higlight DR you've got.

Perhaps the easiest way to consider this is to think in terms of
taking two images of a high dynamic-range scene, using identical
shutter speeds and apertures but with and without Highlight Tone
Priority turned on. Visually, both will be correctly exposed, and by
the grey card test, both shot at the same ISO. But the highlight
clipping point will be shifted by a stop between the two, and
therefore using that definition they will have been shot at ISOs one
stop apart, with an ISO 200 HTP shot considered to be ISO 100.

Now this doesn't actually mean DxO's method is wrong, as they are
only concerned with RAW data not output image files, indeed it's the
only way they can compare RAW output on an equal footing. But it's
purely about technical comparison of RAW data, not about using the
camera.

--
Andy Westlake
dpreview.com/lensreviews
Click to expand...
--



http://photo.net/photos/MariusSabo
 
Not quite what I was meaning I'm afraid. Nikon and Canon have made a claim that the ISO sensitivity is such and such. As the ISO is an international standardisation I would have thought they would have to adhere to the guidelines. So, they have taken monies form me for a product that has promised a specific sensitivity to which I believe is truthful. BUT, if the DXO test has proved that the sensitivity is not as promised then it is not only false advertisement but also misrepresentation of the products capabilities. i.e. a false specification so they can sell more of the product.

--
Slainte (cheers)

You cannot depend on your eyes when your imagination is out of focus. :- Mark Twain
 
at high ISO anywhere from a little worse to the same mostly and a little better for color sensitivity.

seems like the best sensor ever

with the 5dmkii perhaps getting second or the D700/D3 second depending how you look at things.

of course the price is just slightly more than a 5dmkii and the thing is a damn brick

but wow the D800 may be the monster of all monsters when it comes out! Even more MP than the 5dmkii and yet with even better performance at low ISO and perhaps similar overall at high ISO and with pro-AF module and high frame rate....

it does make you wonder what SONY is doing. They must either cheap out on purpose with the associated read electronics for their cams or just not yet have the skills down to make high-quality amps and electronics to actually get the output from their sensor or maybe the nikon sensor actually is somewhat modified from the Sony sensor.
Dr Frank said:
Just discovered the latest test.
http://www.dxomark.com/index.php/eng/Image-Quality-Database/Nikon/D3X

Impressive 13 Bits of the D3X at ISO 100.

Seems to have other sensor than Sony A900.

Comparison between D3X, 5DMKII and 1DsMKIII:

http://www.dxomark.com/index.php/eng/Image-Quality-Database/Compare-cameras/ (appareil1) 287|0 (appareil2) 279|0 (appareil3) 192|0 (onglet) 0 (brand) Nikon (brand2) Canon (brand3) Canon

--
Frank
Click to expand...
 
mariuss said:
I understand that there are 2 different types of tests ... but the
results are totally different.
Click to expand...
That's because we're measuring JPEG output, and the cameras' tone curves come into play; DxO in contrast are measuring RAW. The two tests are complementary.
mariuss said:
Andy, how is the test from Canon 5DII doing? Is it in working?
Click to expand...
It's in progress, with the compact group tests out of the way SLRs are back to top priority.

--
Andy Westlake
dpreview.com/lensreviews
 
The definition of sensitivity in ISO 12232 is more complicated than you'd think.

--
Andy Westlake
dpreview.com/lensreviews
 
interesing points to keep in mind....
Andy Westlake said:
thw said:
And this is another weird thing. REAL test results (for example,
those conducted by Phil) show the opposite is true.

I have a hard time trying to reconcile DXO results with real world
testing by Phil and many other reviewers.
Click to expand...
The discrepancy between DxO's results and the manufacturer's ISOs is
very straightforward to explain, and it's all down to how metering
and exposure works.

Basically the conflict is between two ways of measuring ISO. One
method is to determine the exposure required such that, if you spot
meter off an 18% grey card and then take a picture of it, the grey is
rendered at a luminance of 50% in the resultant image file. I'd argue
this is the method most relevant to how the majority of photographers
work, and if you test cameras this way they will all give essentially
the same answer (always bearing in mind that ISO 12232 allows a
tolerance of 1/3 stop either way, probably as much to cater for
manufacturing variations as anything else).

However DxO use a different method, which is based on the point where
highlights clip to white. This does not necessarily give the same
answer as the grey-point method due to tone curve differences between
cameras, and the difference between the two methods generates the
discrepancy in DxO's results. In fact it turns out that the
difference actually reflects the highlight dynamic range of the
camera; the lower DxO's "true" ISO, the more higlight DR you've got.

Perhaps the easiest way to consider this is to think in terms of
taking two images of a high dynamic-range scene, using identical
shutter speeds and apertures but with and without Highlight Tone
Priority turned on. Visually, both will be correctly exposed, and by
the grey card test, both shot at the same ISO. But the highlight
clipping point will be shifted by a stop between the two, and
therefore using that definition they will have been shot at ISOs one
stop apart, with an ISO 200 HTP shot considered to be ISO 100.

Now this doesn't actually mean DxO's method is wrong, as they are
only concerned with RAW data not output image files, indeed it's the
only way they can compare RAW output on an equal footing. But it's
purely about technical comparison of RAW data, not about using the
camera.

--
Andy Westlake
dpreview.com/lensreviews
Click to expand...
 
Daniel Clune said:
Looking over the results if there even correct seems to me the only
real world differance you might see in actual prints is the extra
dynamic range of the D3X. All the other results i doubt very much if
you would see any real world differance in prints. Hopefuly Canon
will concentrate more on dynmac range on there next round of sensors.
Click to expand...
I hope they don't change it to be like the sony / nikon sensors.

where the base ISO DR is impressive - I'm less enthused about losing a stop for each ISO stop going up - that characteristic isn't present on canon sensors ..

meaning I can float the ISO between 100 and 800 on the 5DII and have pretty close to the same DR characteristic.
 
So are you are saying is that you can't trust either the manufacturers or DXO numbers?

The tolerance seems huge and misleading. I would have thought a standard wouldn't give that much play.
Andy Westlake said:
The definition of sensitivity in ISO 12232 is more complicated than
you'd think.

--
Andy Westlake
dpreview.com/lensreviews
Click to expand...
--
Slainte (cheers)

You cannot depend on your eyes when your imagination is out of focus. :- Mark Twain
 
I read 1/3rd of a stop as 1-3 stops.

--
Slainte (cheers)

You cannot depend on your eyes when your imagination is out of focus. :- Mark Twain
 
Taikonaut said:
DR is only better upto ISO 400 but anything above that it falls
behind marginally.

DXO chart is inaccurate because it shows D700 ahead in DR against
5DMk2 upto ISO 1600 and stays level after that. Also D700 DR is
better than D3x.
Everyone knows 5DMk2 DR is better in than D700.
Click to expand...
You really are something else. Where do you come up with this stuff?
 
The Nikon is for sure a great cam but i am thinking that they use the same sensor as the A900 but having a better pre-processing implemented.
There is also an option that the Sensor have been slightly improved meanwhile.

But maybe its same as usual:

Like allways the same sensor gives much better results in the Nikons which will probably come from.... integrated software algorithms.

Tests like DXO pushes manufacturers to manipulate RAW allready.
So it is not 100% clear if really the Sensor is better or the pre-processing.
 
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