# Canon EOS-1D X DXOMark Sensor Scores



## Canon Rumors Guy (Oct 11, 2012)

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<strong>For those that care


</strong>I was sent an email claiming the results of DXOMark’s testing of the Canon EOS-1D X. I have not yet seen it on their site, so don’t take these numbers as official until they’re up.</p>
<p><strong>DxO score:</strong> 90

<strong>DR:</strong> 12.8

<strong>Color depth:</strong> 24.9 bits

<strong>ISO:</strong> 3296</p>
<p>Do what you will with these numbers. They do show that the 1D X has the “best” technical numbers as far as sensor testing goes. This puts the 1D X above the Nikon D4, but below the D600 & D800. I know people love to debate the numbers from DXOMark.</p>
<p><strong>Canon EOS-1D X at <a href="http://www.bhphotovideo.com/c/product/827036-REG/Canon_5253B002_EOS_1D_X_EOS_Digital.html/bi/2466/kbid/3296" target="_blank">B&H</a> | <a href="http://www.amazon.com/gp/product/B005Y3T1AI/ref=as_li_ss_tl?ie=UTF8&camp=1789&creative=390957&creativeASIN=B005Y3T1AI&linkCode=as2&tag=canorumo-20" target="_blank">Amazon</a> | <a href="http://www.adorama.com/ICA1DX.html?kbid=64393" target="_blank">Adorama</a> | <a href="http://www.normancamera.com/index/page/product/product_id/24696/product_name/Canon+EOS-1D+X+Digital+SLR+Camera+%28Body+Only%29+" target="_blank">Norman Camera</a></strong></p>
<p><strong><span style="color: #ff0000;">c</span>r</strong></p>
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## caruser (Oct 11, 2012)

Oh, it's about DXOMark.

Comfortable chair? Check!

Beverages and snacks? Check!

Let the flaming begin, I'm ready ;-)


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## zim (Oct 11, 2012)

Yeh but it's only DR that matters :

Lol popcorn at the ready…. I just love a good ‘debate’ about a camera I’ll never be able to afford or need…… just imaging all those pros being laughed at now, what were you all thinking ;D ;D ;D


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## Canon-F1 (Oct 11, 2012)

i guess for some the reputation of the DXOmark has just become a bit better. :


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## simonxu11 (Oct 11, 2012)

Canon-F1 said:


> i guess for some the reputation of the DXOmark has just become a bit better. :


 ;D ;D
I think this is the first time admin put Canon's DXO mark on the front page


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## jthomson (Oct 11, 2012)

Looks like we will continue to see Canon improve their sensors.
Nikon still has a lead but in dynamic range but the gap is closing.
The world may not be coming to an end after all. :

I guess the big question is why they didn't use the same sensor for the 5D mark III


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## FrutigerSans (Oct 11, 2012)

jthomson said:


> Nikon *Sony* still has a lead but in dynamic range but the gap is closing.



Fixed.


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## jthomson (Oct 11, 2012)

FrutigerSans said:


> jthomson said:
> 
> 
> > Nikon *Sony* still has a lead but in dynamic range but the gap is closing.
> ...



I'm not at my best in the morning. :-[


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## jthomson (Oct 11, 2012)

dilbert said:


> jthomson said:
> 
> 
> > I guess the big question is why they didn't use the same sensor for the 5D mark III
> ...



Bigger pixels make it a different sensor. It may be the same technology but with pixels size matters.


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## Marsu42 (Oct 11, 2012)

jthomson said:


> I guess the big question is why they didn't use the same sensor for the 5D mark III



Obvious answer: Because the 5d3 is for landscape, too, and thus had to have a higher mp count than the 5d2, and because Canon needed some distinction between 1dx/5d3 except fps when they put the 1dx af into the 5d3. But I guess the dxo numbers - however they compare to Nikon - mean that many people would still happily trade their 22mp 5d3 sensor for a 1dx one with some less mp.


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## preppyak (Oct 11, 2012)

Marsu42 said:


> But I guess the dxo numbers - however they compare to Nikon - mean that many people would still happily trade their 22mp 5d3 sensor for a 1dx one with some less mp.


Well, and this meshes with reality. All the reviews I've seen show that while the 5d3 is great in low-light, the 1DX is that sort of eye-opening camera in terms of how it handles low-light (and the AF system ultimately helps that even more). The review where the Nikon guy partially switched to the 1DX for example, he was talking about how impressed he was with how little noise there was at pretty high ISO levels.


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## daniel_charms (Oct 11, 2012)

simonxu11 said:


> Canon-F1 said:
> 
> 
> > i guess for some the reputation of the DXOmark has just become a bit better. :
> ...



Yeah, I thought he said earlier this year that he was never going to post anything dxomark-related on the front page ever again because their sensor scores were meaningless.

Edit:


> I know people love to debate the numbers from DXOMark.


 Ahh, I guess he's simply realized how great they are for generating page views


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## Canon-F1 (Oct 11, 2012)

i doubt the 4 MP less (bigger photosites) make up for the difference in the DXO results.

i think there must be something else that makes the 1D X sensor better.


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## marekjoz (Oct 11, 2012)

It's dissapointing they didn't give to many reasons to bash their results.


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## JohanCruyff (Oct 11, 2012)

jthomson said:


> Looks like we will continue to see Canon improve their sensors.
> Nikon still has a lead but in dynamic range but the gap is closing.
> The world may not be coming to an end after all. :


Are you sure? I keep reading on the web that the world will disappear next December. 
Maybe DXOmark's positive score is a Sign.


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## K-amps (Oct 11, 2012)

Canon-F1 said:


> i doubt the 4 MP less (bigger photosites) make up for the difference in the DXO results.
> 
> i think there must be something else that makes the 1D X sensor better.



No one talks about color depth... seems this plays a part in the DxO scores and you will see the 1Dx has much higher color depth than other recent offerings from Canon and competes with Nikon.

I always felt there is something that Nikon Sensors exhibit (thats DxO is considering in it's scoring model) that does not affect IQ as much (past a certain level) but affects the DxO scores in favor of Sonikon....


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## Woody (Oct 11, 2012)

I will believe these numbers when I see them on the DXO site itself.

Come to think about it: some folks who tried to lift the shadows in 1DX images do not find the performance any better than the 5D3... Hmmm...


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## Chewy734 (Oct 11, 2012)

What's interesting is that those numbers suggest that the 1D X sensor trumps all other sensors in terms of low-light performance. In fact, based on their numbers they are saying there is a 2x difference in improvement in low-light ISO between the 1D X and the 5D3, than between the 5D3 and 5D2. I just don't see it.


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## stewy (Oct 11, 2012)

Woody said:


> I will believe these numbers when I see them on the DXO site itself.
> 
> Come to think about it: some folks who tried to lift the shadows in 1DX images do not find the performance any better than the 5D3... Hmmm...


What? You don't believe the numbers posted on a rumor's website? How absurd! 

lol, I couldn't resist. 

Seriously though, I've never cared about the numbers. I just look at photos 1:1 and if they look good, detail and color, then that's good enough for me.


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## PackLight (Oct 11, 2012)

It should be obvious that DxO changed the way they are rating the camera. After all they had it right with the D800's high rating.

Obviously Nikon sensors are so much better than Canons that in sensor comparisons a Canon sensor is equivalent to a cave man drawing on the wall with a sharp charcoal stick.

I wonder if I should qualify the above statement, in that it has no merit other than being a sharp charcoal stick to poke at those who like to debate sensor merits.


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## thepancakeman (Oct 11, 2012)

daniel_charms said:


> simonxu11 said:
> 
> 
> > Canon-F1 said:
> ...



But see, this isn't _*from*_ DXO, it's a *rumor* about DXO, so it's all good. ;D ;D


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## sanj (Oct 11, 2012)

Chewy734 said:


> What's interesting is that those numbers suggest that the 1D X sensor trumps all other sensors in terms of low-light performance. In fact, based on their numbers they are saying there is a 2x difference in improvement in low-light ISO between the 1D X and the 5D3, than between the 5D3 and 5D2. I just don't see it.



Is that what they saying? I do not see it either.


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## Chewy734 (Oct 11, 2012)

sanj said:


> Is that what they saying? I do not see it either.



Well, the low-light ISO scores are 3296, 2293, and 1815, for the 1D X, 5D3, and 5D2, respectively.

The difference between the 1D X and 5D3 is 1003, and the difference between the 5D3 and 5D2 is 478. So, the difference between the former is ~2x as much as the latter.

Or am I missing something here?


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## tron (Oct 11, 2012)

Woody said:


> I will believe these numbers when I see them on the DXO site itself.
> 
> Come to think about it: some folks who tried to lift the shadows in 1DX images do not find the performance any better than the 5D3... Hmmm...


Now this is very interesting information, especially for non-sports photographers...


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## preppyak (Oct 11, 2012)

Chewy734 said:


> The difference between the 1D X and 5D3 is 1003, and the difference between the 5D3 and 5D2 is 478. So, the difference between the former is ~2x as much as the latter.
> 
> Or am I missing something here?


Well, you're thinking in terms of direct numbers, whereas ISO isn't proportioned that way. The difference between 1600 and 3200 is the same as between 3200 and 6400, despite the later having twice as great a difference in linear terms. So, really what it is saying is the 5DII and III are pretty close in ISO performance, but the 1DX is another step above.

This is how DxO mark explains it


> Sports Score is based on Low-Light ISO performance (values in ISO index). Low-Light ISO indicates the highest ISO sensitivity to which your camera can be set while maintaining a high quality, low-noise image (based on a Signal-to-Noise-Ratio [SNR] of 30dB, a dynamic range of 9EVs and a color depth of 18bits). As cameras improve, the highest ISO setting to produce 30dB, 9EVs, 18-bit images will continuously increase, making this scale open. Low-Light ISO performance is of primary importance in photojournalism, sports and action photography.


So, they are still following the ISO index, which is based on doubling the previous number being equal to 1-stop. So, for example, the difference between the 5dII and 1DX, by their score, is essentially 1 stop. The difference between the 5dII and 5dIII is 1/3 stop. But, what they are actually measuring for is their own benchmark, which is kind of arbitrary. It's not saying the 1DX is a whole stop better than the other cameras; it's saying its a stop better by their definition of "good". If your standards aren't 30dB, 9EV, 18-bit images, then you might find completely different numbers for the difference between cameras. 

That's why its important for an objective test to state what they are measuring, that way you can decide whether their measurement is important to you or not. Someone who cares less about dynamic range but more about lower read noise might get very different results. Likewise, someone shooting in B+W might care way more about DR and not so much about noise/grain


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## Chewy734 (Oct 11, 2012)

Thanks for the explanation preppyak.


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## jrista (Oct 11, 2012)

Everyone needs to keep in mind, these are not yet posted as official results. Assuming they ARE official results, something else to keep in mind:

A DR of 12.8 is the Print DR. As everyone here who has read the debates about DXO before, particularly from Neuro and myself, Print DR statistics from DXO are very misleading. These numbers are not "impossible" like the D800's 14.4, however to remain objective and consistent in my argument:

Just as you couldn't actually capture a scene with 14.4 literal stops of DR with a D800 *IN-CAMERA*, neither will anyone be able to capture a scene with 12.8 literal stops of DR with a 1D X. For the exact same reasons, the PHYSICAL capabilities of the HARDWARE simply won't allow it. The hardware is rated by DXO's actual measurements, which fall under their Screen DR statistics.

My guess is that the *1D X will still have 11.something stops of real-world HARDWARE DR*. The 12.8 stops is only something that might potentially be possible with the right kind of scaling algorithm, and all it will do is allow you to utilize a little more headroom that is normally consumed by noise in a 100% image (however at the tradeoff of detail and resolution...potentially a LOT of detail and resolution, since it required downscaling). The 12.8 stop DR rating tells you about what SOFTWARE can do if it normalizes (bins) noise, but it does not tell you anything about the physical capabilities of the hardware. (Although if 12.8 stops really is the Print DR, it sounds like the QUALITY of the 1D X's noise is really quite good.) 

Just to put things in perspective, and *maintain a level playing field with consistent arguments*: Screen DR tells you about the hardware (and we don't know this yet, probably won't until DXO actually posts the 1D X results on their site.) Print DR tells you about how clever DXO's testing software is and how capable it is at normalizing noise when downscaling.


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## bdeutsch (Oct 11, 2012)

daniel_charms said:


> simonxu11 said:
> 
> 
> > Canon-F1 said:
> ...


I heard a rumor that CanonRumors is posting DXO rumors just to generate page views. Since the source is this forum, I'll rate it CR3, since it has to be true.


Actor Headshots NYC | Gotham Family Photos | NY Wedding Photography


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## Mooose (Oct 11, 2012)

I'm only buying the 1DX if it scores a 91 or better.


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## neuroanatomist (Oct 11, 2012)

Chewy734 said:


> Well, the low-light ISO scores are 3296, 2293, and 1815, for the 1D X, 5D3, and 5D2, respectively.
> 
> The difference between the 1D X and 5D3 is 1003, and the difference between the 5D3 and 5D2 is 478. So, the difference between the former is ~2x as much as the latter.
> 
> Or am I missing something here?



The fact that ISO sensitivity scale progression is not linear, perhaps?


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## kapanak (Oct 11, 2012)

Well, if the numbers have any credence, then the 1D X just became the new low-light king (according to DxOMark), beating the old low-light monster, the Nikon D3s. That's something, right? ;D

Seriously though, who cares about DxOMark? >_>


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## Marsu42 (Oct 11, 2012)

kapanak said:


> Seriously though, who cares about DxOMark?



We do if a Canon beats Nikon  ... not so much if it's the other way around.


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## infared (Oct 11, 2012)

DXO has no credibility. I always look elsewhere for credible, thoughtful reviews that are backed up with examples and facts. DXO is a joke.
...hey...I just had a thought...does Ken Rockwell do the testing at DXO??????


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## jthomson (Oct 11, 2012)

infared said:


> ...hey...I just had a thought...does Ken Rockwell do the testing at DXO??????



No, Ken thinks the 5D3 is great, despite its low DxO score.


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## Fishnose (Oct 11, 2012)

infared said:


> DXO has no credibility. I always look elsewhere for credible, thoughtful reviews that are backed up with examples and facts. DXO is a joke.
> ...hey...I just had a thought...does Ken Rockwell do the testing at DXO??????



'DxO has no credibility'.... who says? You and a couple of others here who don't like the results they publish, and just don't understand that DxO CANNOT AFFORD TO BULLSHIT. 
Ferchrissake, their test results are just a way to create a buzz around them. They are a software development company who need to test all the bodies and lenses EXACTLY so as to include profiles for them in their software. That's what they do. 
And the test results are a byproduct. 

Whatever.

Anyway, the 1Dx is an absolutely unbelievably good camera. It's not made to get high scores, it's made to get fantastic results in almost impossible situations, especially low light of course. 
And it does that better than any other camera ever constructed.


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## thepancakeman (Oct 11, 2012)

Fishnose said:


> It's not made to get high scores, it's made to get fantastic results in almost impossible situations, especially low light of course.



Silly me; I would think that high scores would be indicative of "fantastic results". In fact maybe that's what some of these folks are saying is the problem with DXO *scores*.


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## FunkyCamera (Oct 11, 2012)

I guess Nikon's money ran out and they're finally giving proper scores too other sensors.

I wonder if they'll have the courage to go back and put the 5D3 score up to where everyone knows it should be, or if this frightened Nikon enough to get some more Nikon cash in dxo's pockets?


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## Chewy734 (Oct 11, 2012)

neuroanatomist said:


> Chewy734 said:
> 
> 
> > Well, the low-light ISO scores are 3296, 2293, and 1815, for the 1D X, 5D3, and 5D2, respectively.
> ...



yeah yeah yeah Neuro... I just figured it wasn't actually ISO numbers, just some random metric they made up (hence the assumption of a linear scale).


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## Wrathwilde (Oct 11, 2012)

Fishnose said:


> They are a software development company who need to test all the bodies and lenses EXACTLY so as to include profiles for them in their software. That's what they do.
> And the test results are a byproduct.



Exactly, I may not agree with their using print DR, or their overall score methodology, but their testing is very exacting, and their raw numbers are probably more accurate than anything else you're likely to find on the web.

If their testing was as bad, or inaccurate as the haters here claim, the DxO Optics Pro software would be a steaming pile of dung that couldn't do anything but degrade the original image. It's not. It's an amazing piece of kit that owes its impressive performance to the fact that DxO's testing is exceedingly accurate. Like it or not, the raw numbers don't lie... although the scoring definitely seems to favor Nikon's strengths.


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## Tayvin (Oct 11, 2012)

Marsu42 said:


> kapanak said:
> 
> 
> > Seriously though, who cares about DxOMark?
> ...



LOL So true.


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## funkboy (Oct 11, 2012)

I think there's so much noise stirred up around DXOMark (no pun intended) because most people don't take the time to read what they're measuring & what the numbers mean. Also few folks use the "screen" button (the default is "print") to see what the raw output of the camera is capable of.

Shame about Canon's consistently lower DR figures; that's the primary thing keeping Canon's scores lower than Nikon over the years.

Lucky for us, they're all great cameras though


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## Woody (Oct 11, 2012)

Fishnose said:


> *'DxO has no credibility'.... who says?* You and a couple of others here who don't like the results they publish, and just don't understand that DxO CANNOT AFFORD TO BULLSHIT...
> 
> Anyway, the 1Dx is an absolutely unbelievably good camera. *It's not made to get high scores, it's made to get fantastic results in almost impossible situations*, especially low light of course.



I hope you see the obvious self-contradiction in what you wrote


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## robbymack (Oct 12, 2012)

Gosh just think about all the pros that are going to need to sell all their gear just to get a d800 because is scored better in some arcane test :


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## tron (Oct 12, 2012)

dilbert said:


> The ratio between the 1DX's low ISO score and the 5D3's low ISO score is 1.43.
> The ratio between the size of the 1DX's pixel and that of the 5D3 is 1.11.
> So quite clearly Canon has better sensor technology available to them than is present in the 5D3.


Damn I must sell my new 5D3  Oh wait the price ratio is about 2


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## infared (Oct 12, 2012)

Woody said:


> Fishnose said:
> 
> 
> > *'DxO has no credibility'.... who says?* You and a couple of others here who don't like the results they publish, and just don't understand that DxO CANNOT AFFORD TO BULLSHIT...
> ...



Hmmmm....seems that his comment is very similar to the results from DXO...As in: all-over-the-place...heh..heh.....


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## verysimplejason (Oct 12, 2012)

At least this brings hope to 6D. Maybe, 6D has a newer sensor technology than 5D3 and 1DX. Maybe, 6D will break Canon's policy of not introducing a better sensor in their newest, cheaper and lower-tier DSLRs. I'm keeping my fingers crossed. After all, for my requirements, the announced AF of 6D is enough for me (super center AF sensitivity). I'm just waiting if their sensor DR is better than 5D3. 5D3 and 1DX can beat 6D with their superior AFs for all I care. I just need a better DR and less banding for its sensor.


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## tron (Oct 12, 2012)

verysimplejason said:


> At least this brings hope to 6D. Maybe, 6D has a newer sensor technology than 5D3 and 1DX. Maybe, 6D will break Canon's policy of not introducing a better sensor in their newest, cheaper and lower-tier DSLRs. I'm keeping my fingers crossed. After all, for my requirements, the announced AF of 6D is enough for me (super center AF sensitivity). I'm just waiting if their sensor DR is better than 5D3. 5D3 and 1DX can beat 6D with their superior AFs for all I care. I just need a better DR and less banding for its sensor.


This is highly unlikely. Also, if it happens it will be a bad joke. The camera with the best DR and lowest noise (hypothetically speaking of course) to have the least capable autofocus, fps, etc!!!


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## neuroanatomist (Oct 12, 2012)

tron said:


> This is highly unlikely. Also, if it happens it will be a bad joke. The camera with the best DR and lowest noise (hypothetically speaking of course) to have the least capable autofocus, fps, etc!!!



Right. Because we were nowhere close to that with the 5D Mark II. :-X


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## tron (Oct 12, 2012)

neuroanatomist said:


> tron said:
> 
> 
> > This is highly unlikely. Also, if it happens it will be a bad joke. The camera with the best DR and lowest noise (hypothetically speaking of course) to have the least capable autofocus, fps, etc!!!
> ...


Ooops you are correct!


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## verysimplejason (Oct 12, 2012)

tron said:


> verysimplejason said:
> 
> 
> > At least this brings hope to 6D. Maybe, 6D has a newer sensor technology than 5D3 and 1DX. Maybe, 6D will break Canon's policy of not introducing a better sensor in their newest, cheaper and lower-tier DSLRs. I'm keeping my fingers crossed. After all, for my requirements, the announced AF of 6D is enough for me (super center AF sensitivity). I'm just waiting if their sensor DR is better than 5D3. 5D3 and 1DX can beat 6D with their superior AFs for all I care. I just need a better DR and less banding for its sensor.
> ...



Well, if it happens, it will not be the first. Not everybody requires that magnanimous, amazing and spectacular AF of 5D3 and 1DX.  You know that if this happens, all canon owners will be benefited if not now then in the future because at least you know that Canon is continually improving their sensor technology. For me, even if I'm an owner of 1DX (only in my dreams), if they introduce a cheaper camera but with a better sensor, I'll not be bitter because I know eventually I'll be able to get that sensor technology soon.


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## verysimplejason (Oct 12, 2012)

tron said:


> neuroanatomist said:
> 
> 
> > tron said:
> ...


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## tron (Oct 12, 2012)

verysimplejason said:


> tron said:
> 
> 
> > verysimplejason said:
> ...


That is correct. I believe however that for the moment (hmmm year or two?) the 1Dx at least will not be surpassed in high ISO performance.


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## GuyF (Oct 12, 2012)

DXOMark is all very well but not everything that can be measured matters and not everything that matters can be measured (to quote some patent office clerk).

The question should really be - how many would trade their DSLR with all their bells and whistles and go back to shooting film or slide?


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## Fishnose (Oct 12, 2012)

Woody said:


> Fishnose said:
> 
> 
> > *'DxO has no credibility'.... who says?* You and a couple of others here who don't like the results they publish, and just don't understand that DxO CANNOT AFFORD TO BULLSHIT...
> ...



Wow, you don't have a clue, do you. I write that the 1Dx is "not made to get high scores, it's made to get fantastic results in almost impossible situations". 
In what way does that contradict anything else I wrote?

I'll write it again, to make sure you get it this time: Canon did not make the 1Dx to score one way or the other in any test, Canon made it to be an incredibly good camera at what it does. And Canon succeeded.


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## verysimplejason (Oct 12, 2012)

GuyF said:


> DXOMark is all very well but not everything that can be measured matters and not everything that matters can be measured (to quote some patent office clerk).
> 
> The question should really be - how many would trade their DSLR with all their bells and whistles and go back to shooting film or slide?



Most of us knows that's true but if for example, I'm going to buy my first FF, of course I want the best bang for my bucks and requirements and thus some measurements are needed for comparisons. It's not only measurements btw but also reviews from users and photographers. 

As for shooting film or slide, I'd go back as soon as I have more money and time to spend. As of now, I can't forego the comfort of shooting digital (just like most of us here). I am a programmer during weekdays, hobby photographer during weekends. Besides photography, I also want to spend time with my family. I've also got other hobbies besides photography. I hope that explains it.


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## Viggo (Oct 12, 2012)

DxO can't tell me anything at all about the 1d X i don't already know. It's so far ahead in every way compared to any of the cameras I have ever tried. The mk4 was tons better than the 1d3, but there were still lots of things not perfect with it. The 1d X lacks the f8 focusing and the superlow light af lock and red lit up points. Those things doesn't matter to me, and everything else it just doesn't do better than anything else, it does it to perfection. A real tool I can trust for 100% of my pictures. Only eyes will capture a moment better..


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## nightbreath (Oct 12, 2012)

Viggo said:


> ... The 1d X lacks the f8 focusing and the superlow light af lock and red lit up points. Those things doesn't matter to me, and everything else it just doesn't do better than anything else, it does it to perfection. A real tool I can trust for 100% of my pictures. *Only eyes will capture a moment better..*


Unless the camera is in the high-speed mode


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## Viggo (Oct 12, 2012)

nightbreath said:


> Viggo said:
> 
> 
> > ... The 1d X lacks the f8 focusing and the superlow light af lock and red lit up points. Those things doesn't matter to me, and everything else it just doesn't do better than anything else, it does it to perfection. A real tool I can trust for 100% of my pictures. *Only eyes will capture a moment better..*
> ...



That is true. I was thinking about IQ..


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## Larry (Oct 12, 2012)

Fishnose said:


> Woody said:
> 
> 
> > Fishnose said:
> ...



+1 No contradiction!


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## Woody (Oct 13, 2012)

Fishnose said:


> Woody said:
> 
> 
> > Fishnose said:
> ...



So, according to you, (i) DXOMark results are accurate (ii) Canon 1DX produces fantastic results *REGARDLESS* of its DXOMark scores.

This means whatever DXOMark measures is *USELESS* since their results have no correlation to real world results. Correct?


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## heptagon (Oct 13, 2012)

Well they do matter for a few specific use cases. E.g. if you can't get the lighting right and need to brighten your pictures.


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## neuroanatomist (Oct 13, 2012)

heptagon said:


> Well they do matter for a few specific use cases. E.g. if you can't get the lighting right and need to brighten your pictures.



I'll buy that. But the examples provided recently in other threads don't show 'can't get the lighting right', they show _intentionally choosing to get the lighting wrong_, then brightening the image that should not have needed brightening if properly exposed to begin with.


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## Viggo (Oct 13, 2012)

neuroanatomist said:


> heptagon said:
> 
> 
> > Well they do matter for a few specific use cases. E.g. if you can't get the lighting right and need to brighten your pictures.
> ...



+1 I expose 5/8 to the right by moving my 0 ev, and this leads to pulling shadows DOWN or even the whole exposure, if need. I haven't pulled UP a single image with the 1d x, the metering is fantastic. Leaving me with perfect exposure and no need to do it wrong and try to rescue it later. Learn how to expose instead....


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## elflord (Oct 13, 2012)

Woody said:


> So, according to you, (i) DXOMark results are accurate (ii) Canon 1DX produces fantastic results *REGARDLESS* of its DXOMark scores.
> 
> This means whatever DXOMark measures is *USELESS* since their results have no correlation to real world results. Correct?



That's not what he said at all.

He said that Canon didn't design their camera with DXO's benchmarks in mind. Instead, the manufacturer (Canon) have their own design goals, performance goals, use cases, etc in mind. They also almost certainly do some kind of internal benchmarking.

That doesn't mean that DxOMark's performance measurement is _uncorrelated_ with real world performance (or for that matter, benchmarks that Canon might use internally to test their products).

It also most certainly doesn't mean that DxOMark's performance measures are _useless_.

There are at least two compelling advantages of DxOMark here -- one is the simple practical one -- as we do not have access to Canon's internal processes, we can't use their internal benchmarking results to appraise the 1DX or compare it to competing products (again, assuming Canon have an internal testing regimen, one would expect that they would run all of their own, and several competing products through it). 

Second, even if we could see those results, it would be misleading to compare cameras that had been tuned to those specific testing processes with those that hadn't (basically, it would be analogous to in-sample versus out-of-sample testing)


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## Woody (Oct 13, 2012)

elflord said:


> There are at least two compelling advantages of DxOMark here -- one is the simple practical one -- as we do not have access to Canon's internal processes, we can't use their internal benchmarking results to appraise the 1DX or compare it to competing products (again, assuming Canon have an internal testing regimen, one would expect that they would run all of their own, and several competing products through it).
> 
> Second, even if we could see those results, it would be misleading to compare cameras that had been tuned to those specific testing processes with those that hadn't (basically, it would be analogous to in-sample versus out-of-sample testing)



Ultimately, real world results are what counts, yes? Photographers buy cameras to capture images, not to pass specific testing processes or specific testing regimes, ya?

So, can you point out specific real world scenarios that Canon's cameras perform really well, outside of what DXOMark can ever reveal? Perhaps Canon's internal test regimes are tailored for such instances?


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## elflord (Oct 13, 2012)

Woody said:


> elflord said:
> 
> 
> > There are at least two compelling advantages of DxOMark here -- one is the simple practical one -- as we do not have access to Canon's internal processes, we can't use their internal benchmarking results to appraise the 1DX or compare it to competing products (again, assuming Canon have an internal testing regimen, one would expect that they would run all of their own, and several competing products through it).
> ...



To address your first question(s) -- 

I'm not sure what you think you're disagreeing with. Better equipment helps us get "real world results", and the sensor is a key part (but not all of) our camera equipment. Photographers have gotten great results before the latest sensors were available, indeed, before digital was available. 

If you're happy to use the same equipment that produced great results for photographers who didn't have access to the latest gear, then you have absolutely no need to pursue the latest technology.

However, if you are in the market for the best technology the market has to offer, benchmark results count.

You can wait until the technology in question has an established track record, to see which products get the best "real world results" but there are least two problems with this -- one is that by the time this established track record is realized, it is not the latest tech any more. 

The other is that "real world results" depend more on the skill of the photographer than the technology. You can buy the same equipment used by the photographer produces the greatest "real world results", but the photographers talent does not come in the box with the equipment. 

In answer to your second question, DxOMark only test sensors. The camera is much more than a sensor. Canon almost certainly include considerable testing of features including but not limited to ergonomics, durability (weather proofing and longevity). and autofocus performance. And there are yet other factors that can't really be tested, but are important all the same -- Canon's unique ability and willingness to stand behind their products. This is a combination of a first rate support system, and complete control over their product line. For example, there is no other full format DSLR manufacturer that completely manage their product development (cameras, sensors, lenses). Nikon's performance numbers are impressive but one could reasonably doubt _Sony's_ commitment to _Nikon's_ DSLR line. Nobody doubts Canon's commitment to Canon. Canon's strategic decision to avoid taking the easy way out and just buying the sensor might seem to hurt them in the short run, but it is a strategic decision that takes the long view.


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## jrista (Oct 13, 2012)

elflord said:


> Woody said:
> 
> 
> > elflord said:
> ...



Very well said! +1


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## Fishnose (Oct 13, 2012)

Woody said:


> Fishnose said:
> 
> 
> > Woody said:
> ...



Wow, you really are confused. :

If the DxO figures rumored are in fact the official DxO results, then the numbers mentioned are exceptionally high and the 1Dx gets fantastic results. 
Remember, DxO are testing the SENSOR - not the camera. 
The camera obviously is fantastic - and, according to DxO, so is the sensor. The numbers are stellar.

That the D600 and D800 get even higher marks (for their SENSORS) has got nothing to do with anything in this situation - they're a different kind of camera.

The 1Dx is made specifically for low light work and other difficult situations. The D600 and D800 are definitely not made for this.

So - what was your point again? In what way are DxO not credible? Be specific now, explain your point with some kind of useful argument other than 'DxO is a joke' - as infared put it. 
Very erudite, to say the least


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## jrista (Oct 13, 2012)

Fishnose said:


> Woody said:
> 
> 
> > Fishnose said:
> ...



I think it the conversation has become rather confused. In general, DXO is a good resource when it comes to IQ. Its not that DXO is entirely non-credible. The problem many of us have with DXO is specifically with their "Print DR" statistic. It is not a measurement, it is a rating, and it is a weighted rating at that. Not only that, but their "Print DR" statistic seems to have an overbearing weight on overall sensor score, making it seem like the only thing that matters in a sensor is dynamic range. The fact that Canon sensors are capable of considerably better high ISO performance these days is so weakly rated that it doesn't seem to matter...at least according to DXO.

I mentioned this before, but perhaps it was lost in other conversation. My guess is that the 12.8 stops of DR for the 1D X is the "Print DR". It doesn't matter the camera, Canon, Nikon, or anyone else...I think that the Print DR figure is exceptionally misleading and falsely indicative of a sensor's capabilities. My guess is that the 1D X still only has 11.something stops of DR, like all the rest of Canon's cameras.



jrista said:


> Everyone needs to keep in mind, these are not yet posted as official results. Assuming they ARE official results, something else to keep in mind:
> 
> A DR of 12.8 is the Print DR. As everyone here who has read the debates about DXO before, particularly from Neuro and myself, Print DR statistics from DXO are very misleading. These numbers are not "impossible" like the D800's 14.4, however to remain objective and consistent in my argument:
> 
> ...


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## JR (Oct 13, 2012)

jrista said:


> I mentioned this before, but perhaps it was lost in other conversation. My guess is that the 12.8 stops of DR for the 1D X is the "Print DR". It doesn't matter the camera, Canon, Nikon, or anyone else...I think that the Print DR figure is exceptionally misleading and falsely indicative of a sensor's capabilities. My guess is that the 1D X still only has 11.something stops of DR, like all the rest of Canon's cameras.



I would tend to agree there. Having both the 1DX and the D4 (and I guess the D800), the only number in those DxO "rumored" scores that surprised me was the 12.8 DR. Overall I do think the 1DX is a superior camera then the D4, however I still find from real life shooting that my D4 gives me more dynamic range when I shoot outside and I dont find the difference marginal either...

One of the biggest difference between both camera also seems to be metering which could explain in part my perceived preference for one camera over the other in certain shooting condition...


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## peederj (Oct 13, 2012)

I've come to the conclusion that the 1DX is worth paying double for vs. the 5D3. With Big Megapixel Talk on the horizon though, and Canon needing an answer to the D800e (which has a damn fine sensor and that's about it), maybe it's better I wait a bit before trading in this camera that I only got this year.


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## jrista (Oct 13, 2012)

peederj said:


> I've come to the conclusion that the 1DX is worth paying double for vs. the 5D3. With Big Megapixel Talk on the horizon though, and Canon needing an answer to the D800e (which has a damn fine sensor and that's about it), maybe it's better I wait a bit before trading in this camera that I only got this year.



It would indeed be interesting if Canon provided a 46.1mp FF camera without a low pass filter. I'd be very interested in that for landscape work.


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## elflord (Oct 13, 2012)

jrista said:


> I mentioned this before, but perhaps it was lost in other conversation. My guess is that the 12.8 stops of DR for the 1D X is the "Print DR". It doesn't matter the camera, Canon, Nikon, or anyone else...I think that the Print DR figure is exceptionally misleading and falsely indicative of a sensor's capabilities. My guess is that the 1D X still only has 11.something stops of DR, like all the rest of Canon's cameras.



You keep repeating it, but it's still wrong. It's wrong because the low end of the dynamic range is determined by SNR, and SNR changes when you downsample. The lower end of the dynamic range is NOT some point at which the signal is clipped. It is not in general true that a pixel is completely insensitive outside the dynamic range. The baseline of dynamic range is defined in terms of SNR, not detectability. 

You do run into a "quantization limit" at the number of bits in the ADC (assuming that both the sensor response and the ADC itself are linear), but even then, you do eliminate shadow noise and therefore increase your usable dynamic range. But this is not an issue with the new canon bodies because their reported dynamic range does not exceed that of the ADC. 

I should add further that the screen "dynamic range" is also in some sense "just a score". A SNR of 0db is extremely noisy (as a point of comparison the powershot S90's noise at max ISO 18% gray is 13db), so depending on your criteria, the "usable dynamic range" might be a few stops less than that indicated by the screen score.


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## jrista (Oct 13, 2012)

elflord said:


> jrista said:
> 
> 
> > I mentioned this before, but perhaps it was lost in other conversation. My guess is that the 12.8 stops of DR for the 1D X is the "Print DR". It doesn't matter the camera, Canon, Nikon, or anyone else...I think that the Print DR figure is exceptionally misleading and falsely indicative of a sensor's capabilities. My guess is that the 1D X still only has 11.something stops of DR, like all the rest of Canon's cameras.
> ...



In the case of the 1D X, what you describe _might_ indeed be the case. It is a bit different than the D800, wherein 14.4 stops of DR surpasses the bit depth of the ADC and the limit imposed by quantization. If we were purely talking about the Gaussian type of noise produced by the Poisson distribution of photons, I'd probably agree. I am not sure the same simplistic rules that apply to gaussian noise apply to the non-random forms of electronic/read noise, which is the primary cause of a LOSS of DR at low ISO in Canon sensors.


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## peederj (Oct 14, 2012)

Mikael,

FWIW, you're even more nuts.

Hugs and Kisses... :-*


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## jrista (Oct 14, 2012)

Mikael Risedal said:


> *The Canon brand fanatics writes about arguments regarding why something suddenly not important anymore (when "their" brand suddenly is not the best ) this take quite comical proportions ... Some very active writers, among others here at Canonrumors's are direct rabid - this despite the notice that they are intelligent enough to see the connections, there is an instinctive religious barrier that prevents them to see what's right in front of their eyes ...
> *



You might carry a bit more weight with your arguments if you actually posted facts, undoctored evidence, and _did not resort to *personal attacks*_. I have respect for _elflord_, even if I don't fully agree with his assessments (which I primarily do agree, I just disagree on some of the finer points, as do a number of others here).

You, on the other hand, well to be frank I don't have a shred of respect for you. I'd also point out my fanaticism isn't really about Canon. It is about DXO's scoring system and my general dislike of it, and the often unenlightened application of their scores by die-hard Nikon fanatics. ;P I apply my same skepticism for DXO's scoring in regards to Canon as I do in regards to Nikon (or any other brand, for that matter).

I'll freely admit that I greatly dislike the notion that simply because the D800 _is_ a great camera, then all other cameras (and particularly Canon cameras) suck donkey danglers, and that the D800 is the end-all, be-all of cameras everywhere, infinitely capable of everything to everyone (a notion you would certainly think was true if you believed all the drivel from the majority of the raging Nikon fanbase). The advent of new & improved technology does not immediately and entirely negate previous technology, or diminish the quality it previously attained. The regular arguments to the contrary, and the bogus doctored, contrived or staged evidence to try and prove that bogus fact, are the fundamental basis of my tirade against such inanity. I've never disagreed that Exmor is some phenomenal technology, nor have I ever said Canon sensors do as well (although I _certainly_ believe they can do as well or better, and probably will in coming Canon sensor generations). I simply deny that the difference between Canon _cameras_ and Nikon _cameras_ is as big as it is usually made out to be by the fanatical branch of the Nikonites. I also believe a periodic reality check to that fact is beneficial to those potentially...gullible enough?...to waste time, effort, and money jumping ship and switching brands when in _most_ cases (there are a few outliers) it is unnecessary, and people could save their hard-earned cash.


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## jocau (Oct 14, 2012)

The 1D X scores still can't be found on the DXOMark website. 12,8 stops of DR out of a Canon sensor? I won't believe it until I see it.


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## peederj (Oct 14, 2012)

The conspiracy theorists would suggest DxO is waiting the completion of "sponsorship negotiations" as to what the final score will be.


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## LetTheRightLensIn (Oct 15, 2012)

jrista said:


> elflord said:
> 
> 
> > jrista said:
> ...



advice:

just quit before you dig an even deeper hole on this issue 

Elford has it right.


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## thepancakeman (Oct 15, 2012)

jocau said:


> The 1D X scores still can't be found on the DXOMark website. 12,8 stops of DR out of a Canon sensor? I won't believe it until I see it.



And that's what cracks me up about this whole thing. If it were that significant or that drastic, you wouldn't need a test to tell you about it, you'd see it in the photos. Just my $.02.


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## jrista (Oct 15, 2012)

thepancakeman said:


> jocau said:
> 
> 
> > The 1D X scores still can't be found on the DXOMark website. 12,8 stops of DR out of a Canon sensor? I won't believe it until I see it.
> ...



Well, it would only be visible in photos that were sufficiently downscaled, and downscaled in an appropriate manner with a proper algorithm that actually maximized the potential for DR gains. You would NOT see it in photos strait out of the camera (that goes for both D800 photos and 14.4 stops of DR as well as for the 1D X and 12.8 stops of DR), since Print DR is intrinsically dependent on proper downscaling.


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## RLPhoto (Oct 15, 2012)

Mikael Risedal said:


> *The Canon brand fanatics writes about arguments regarding why something suddenly not important anymore (when "their" brand suddenly is not the best ) this take quite comical proportions ... Some very active writers, among others here at Canonrumors's are direct rabid - this despite the notice that they are intelligent enough to see the connections, there is an instinctive religious barrier that prevents them to see what's right in front of their eyes ...
> *



Lol, and this is the same dude who didn't know that the nikon 51 Point AF hasn't changed much since last generation. :-X


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## Speed2 (Oct 15, 2012)

I will still look at it, but learned a long time ago, nothing beats peoples real world hands on experience. I try to buy Lenses that way also. The 1d x is my 5th Digital in 12 years. Still have my old Minolta xg7. Relic like me...lol


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## RLPhoto (Oct 15, 2012)

Mikael Risedal said:


> RLPhoto said:
> 
> 
> > Mikael Risedal said:
> ...



Ignorance is bliss for fanboi's like yourself. :

Canon 61 pt AF > Nikon 51 pt AF. done.


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## dtaylor (Oct 15, 2012)

elflord said:


> You keep repeating it, but it's still wrong. It's wrong because the low end of the dynamic range is determined by SNR, and SNR changes when you downsample.



This is the belief of a math geek who spends too much time with graphs and not enough time with real photographs. Down sampling throws away noise *and* detail. Dynamic range is the range of *useful photographic detail*. It is *not* the simple difference between two numbers on a graph.

Try this: shoot 4x5 Velvia. Drum scan it. Down sample to 10 MP. Did you all of a sudden gain 3-4 stops of shadow detail? No? Hmmm...

Side note: arguments like this are why I hate DR by software analysis. It has zero bearing on the real world. It just leads to paragraphs and paragraphs of irrelevant and pointless theorizing. Shoot a Stouffer transmission step wedge and look at it with your own two eyes. That tells you what you can expect in the real world.


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## dtaylor (Oct 15, 2012)

RLPhoto said:


> Canon 61 pt AF > Nikon 51 pt AF. done.



Nonsense. Point count != superior AF. In my experience the 7D's AF is superior to the D7000's, practically on par with the earlier 45 point 1D bodies and several Nikon 51 point bodies, and it only has 19 points.

I don't honestly know who has the best AF right now because I don't spend sufficient time with the top tier bodies. But AF is an extremely complicated thing to objectively test, and subjective opinions are open to bias and error. AF performance can also be better on body A for situation 1, but better on body B for situation 2, etc, etc. Not to mention that lenses are at least as important as anything in the body, and it's a mistake to assume similar lenses from two manufacturers have similar AF.

Even with a case as one sided on paper as the 6D and D600 you can't conclusively say one body is always better than another. There's little point in discussing the top tier bodies unless you happen to own and shoot both regularly under a range of challenging conditions.


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## Fishnose (Oct 15, 2012)

Concerning all the discussions about whether or not 8Mp is a reasonable number for the 'print' scores:

DxO say "...high-resolution sensors will gain more SNR, DR, TR and CS when reduced to a lower reference resolution. For DxOMark Sensor Overall Score and Metrics, we chose a reference resolution equal to 8 Megapixels, which is a bit less than a 12" x 8" print with a 300dpi printer. However, *any other resolution can be chosen, as doing so only shifts the normalized values by a constant (because the reference resolution appears only as a logarithm in the formulas above)*.
What should be remembered is that doubling the resolution adds:

3dB to the normalized SNR
0.5 bit to the normalized DR
0.5 bit to the normalized TR
1.5 bit to the normalized CS"

I'm guessing that at the time they chose 8Mp there were probably no cameras capable of anything over say 25Mp other than a couple of MF models. And many sensors were 8 or 12Mp. That's just a few years ago.


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## dtaylor (Oct 15, 2012)

Fishnose said:


> What should be remembered is that doubling the resolution adds:
> 
> 3dB to the normalized SNR
> 0.5 bit to the normalized DR



So according to DxO if we drum scan 4x5 Velvia, a 6 stop film, and down sample to 8 MP, we will end up with 9 stops of usable photographic detail? :

Go ahead and try it ;D


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## RLPhoto (Oct 15, 2012)

dtaylor said:


> RLPhoto said:
> 
> 
> > Canon 61 pt AF > Nikon 51 pt AF. done.
> ...



You must have never used the sheer awesomeness of the canon 61-Point AF system And yes, I've used nikons excellent 51-point system as well. So yes, I can say the Canon AF system is better than nikons right now. Plus, I never said that point count makes a better AF system, because then S0&y would be the best then. :

My Xsi was good
My 7D is Better
but my 5D3 is Great.


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## neuroanatomist (Oct 15, 2012)

dtaylor said:


> This is the belief of a math geek who spends too much time with graphs and not enough time with real photographs. Down sampling throws away noise *and* detail. Dynamic range is the range of *useful photographic detail*. It is *not* the simple difference between two numbers on a graph.
> 
> Try this: shoot 4x5 Velvia. Drum scan it. Down sample to 10 MP. Did you all of a sudden gain 3-4 stops of shadow detail? No? Hmmm...



+1



dtaylor said:


> Side note: arguments like this are why I hate DR by software analysis. It has zero bearing on the real world. It just leads to paragraphs and paragraphs of irrelevant and pointless theorizing. Shoot a Stouffer transmission step wedge and look at it with your own two eyes. That tells you what you can expect in the real world.



FWIW, one of the things that I do at some point after getting a new camera body is put a Stouffer T4110 on a light box, and use that to determine the 'typical' DR I get across the available ISO settings, and how far I can push that DR using more intensive post-processing of the RAW file. To me, that's a relevant empirical measure that actually helps me determine exposure when taking real pictures in the real world. My DR estimates are always less what DxO determines manipulates and calls a Landscape Score.


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## elflord (Oct 15, 2012)

dtaylor said:


> elflord said:
> 
> 
> > You keep repeating it, but it's still wrong. It's wrong because the low end of the dynamic range is determined by SNR, and SNR changes when you downsample.
> ...



Of course it throws away noise AND detail, the fact that there is a noise-detail tradeoff is the point ! 

The point is that you normalize all cameras to the same resolution so that all cameras are at _the same level of detail_. The test is, how much dynamic range does each camera have _for some given resolution_.

I understand that there's a whole other can of worms regarding at what point "useful" dynamic range starts -- is it SNR = 0db, 10db, or maybe even 20db ? But I don't think that's what you are referring to.

It doesn't make any sense to compare data points which represent different tradeoffs/choices on the noise-detail continuum. Now, to your example -- 



> Try this: shoot 4x5 Velvia. Drum scan it. Down sample to 10 MP. Did you all of a sudden gain 3-4 stops of shadow detail? No? Hmmm...



Here's a different test for you -- sample it at 10MP, create another image at 40MP. Then compute the "blackpoint" (SNR = 0db) of the two images. 

Now I take it that we agree that the images both have the same "true" dynamic range, but I put it to you that the measured blackpoint on the 40MP will be at a higher luminance level, and therefore the _measured per-pixel dynamic range_ will be lower on the 40MP image. 

Without normalization, your measured dynamic range has more to do with how the data was sampled and less with this *useful photographic detail* that you're so fond of. 



> Shoot a Stouffer transmission step wedge and look at it with your own two eyes. That tells you what you can expect in the real world.



For what it's worth, I am in agreement with you here -- if a test site were to include such shots, and allow the user to judge, it would be quite valuable. Of course it wouldn't resolve the debate about whether to "normalize" to a common resolution (or for that matter, what to do about different ISOs).


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## elflord (Oct 15, 2012)

neuroanatomist said:


> FWIW, one of the things that I do at some point after getting a new camera body is put a Stouffer T4110 on a light box, and use that to determine the 'typical' DR I get across the available ISO settings, and how far I can push that DR using more intensive post-processing of the RAW file. To me, that's a relevant empirical measure that actually helps me determine exposure when taking real pictures in the real world. My DR estimates are always less what DxO determines manipulates and calls a Landscape Score.



Yes, probably because DxO use 0db as their baseline. A 0db SNR isn't really "usable" even by the most liberal of standards. In comparison, even at the very permissive ISO settings on most modern digital cameras, most have > 10db SNR at 18% gray, max ISO.

So assuming you start from the screen score, you could lose a stop or two depending on how stringent your idea of "usable" dynamic range is.


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## jrista (Oct 16, 2012)

dtaylor said:


> elflord said:
> 
> 
> > You keep repeating it, but it's still wrong. It's wrong because the low end of the dynamic range is determined by SNR, and SNR changes when you downsample.
> ...



Thanks for the backup, dtaylor.  I think this nails it on the head (eloquently so...I am not so eloquent):



> Dynamic range is the range of *useful photographic detail*. It is *not* the simple difference between two numbers on a graph.


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## jrista (Oct 16, 2012)

Fishnose said:


> Concerning all the discussions about whether or not 8Mp is a reasonable number for the 'print' scores:
> 
> DxO say "...high-resolution sensors will gain more SNR, DR, TR and CS when reduced to a lower reference resolution. For DxOMark Sensor Overall Score and Metrics, we chose a reference resolution equal to 8 Megapixels, which is a bit less than a 12" x 8" print with a 300dpi printer. However, *any other resolution can be chosen, as doing so only shifts the normalized values by a constant (because the reference resolution appears only as a logarithm in the formulas above)*.
> What should be remembered is that doubling the resolution adds:
> ...



This is exactly what is wrong with DXO's mentality, here, though:



> DxO say "...high-resolution *sensors* will gain more SNR, DR, TR and CS when reduced to a lower reference resolution.



The *sensor* gains NOTHING...its a fixed construct with fixed attributes. The only thing that changes when scaling an image down is _the image._ The only thing that indicates is the capabilities of the software doing the downscaling...it tells you little of the sensor (if it really tells you anything...I think the point is debatable.) Whatever you do with an image in post, that has no direct bearing on what the sensor is actually capable of. The only things that tell you about the sensor are *measurements*. DXO does provide that...in their "Screen" statistics. 

The only way to discuss sensors _objectively_ is to reference actual measurements. From the outcry of the D800 fanatic, one would think it actually had a really crappy sensor by the way they demand images be normalized in size to allow the only form of objective comparison a study of a sensor could possibly endure. Ironically, the D800, D600, and D7000 all still outperform Canon sensors when you only look at the objective sensor measurements, so the inane debate about Print DR and its subjectivity is really just that...inane.


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## jrista (Oct 16, 2012)

RLPhoto said:


> dtaylor said:
> 
> 
> > RLPhoto said:
> ...



While I think that in the aggregate the anecdotal evaluations of Canon's 61pt AF system would generally concur, that it is currently the best available as it produces a higher rate of keepers, and really good keepers at that...I have to agree with dtaylor that it is all still anecdotal. It can be tough to objectively test an AF system, so we can't really claim that any test results to date are anything other than subjective. Thats not terrible though...statistical analysis of subjective tests can still produce useful results when aggregated, and I think those results speak resoundingly in favor of the 1D X's AF system.


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## elflord (Oct 16, 2012)

jrista said:


> The *sensor* gains NOTHING...its a fixed construct with fixed attributes. The only thing that changes when scaling an image down is _the image._ The only thing that indicates is the capabilities of the software doing the downscaling...it tells you little of the sensor



Again, the _sensor_ does not consist of a single pixel. DxO's normalization method does not use any fancy downsampling algorithms, it's based on simple averaging. 



> Whatever you do with an image in post, that has no direct bearing on what the sensor is actually capable of.



It has nothing to do with post processing, it is about resampling so that the resolutions are the same. Simple averaging. Not applying noise removal algorithms, etc. 



> The only things that tell you about the sensor are *measurements*. DXO does provide that...in their "Screen" statistics.



The problem is that the screen rating, using their definitions, using a 36 megapixel camera is not comparable to the same rating with a 10mpx camera. If you want to ask some question like "how do these two cameras compare _if I use the same noise/resolution tradeoff for both cameras_, then you need the print rating. 


> The only way to discuss sensors _objectively_ is to reference actual measurements.



What is your definition of a "measurement" ? The screen score is hardly a single measurement. It's the number of stops between the measured saturation point (possibly with some extrapolation), and the (probably interpolated or extrapolated) SNR=0db point on the noise / luminosity curve. What difference does it make if I throw in an extra term to my formula which normalizes to 8 megapixels ? It does change the interpretation of the number, but maybe that's the number some people are interested in. It's the number _I'm_ more interested in, and I do understand the underlying math reasonably well. Screent _rating_ (not measurement) is only valid if you view 100% crops all the time. 



> From the outcry of the D800 fanatic, one would think it actually had a really crappy sensor by the way they demand images be normalized in size to allow the only form of objective comparison a study of a sensor could possibly endure. Ironically, the D800, D600, and D7000 all still outperform Canon sensors when you only look at the objective sensor measurements, so the inane debate about Print DR and its subjectivity is really just that...inane.



There's nothing "subjective" about the print DR measurement. The relative difference between print DR scores does not depend on whether they normalize to 8mpx or 12mpx or 6mpx. The choice of what resolution to normalize to is arbitrary but it doesn't change the rankings between sensors. 

If there is anything "subjective" in the dynamic range score, it is the choice to use 0db as the baseline instead of some other number. The choice of of baseline could in theory change the relative performance of two cameras (though in practice I think this would be unlikely)


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## neuroanatomist (Oct 16, 2012)

jrista said:


> While I think that in the aggregate the anecdotal evaluations of Canon's 61pt AF system would generally concur, that it is currently the best available as it produces a higher rate of keepers, and really good keepers at that...



I agree that it's anecdotal. I'll add my anecdote. I've got very little experience with Nikon bodies, so I make no attempt at comparison. I can tell you that I love and hate the 1D X's AF system. I love it, because it locks on fast, stays locked on, and delivers sharp shots consistently. I hate it, because it locks on fast, stays locked on, and delivers sharp shots consistently, and that fact combined with the 12 fps frame rate means a harder time triaging my images.  

Seriously, though - in a burst from the 7D, I could always count on throwing away a few frames as OOF without even looking at them more magnified than reduced to fit my monitor (which is at least a 17" MBP at 1920x1200, and at best a 27" Apple Thunderbolt Display at 2560x1440). With the 1D X, they are almost always all in focus.


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## jrista (Oct 16, 2012)

neuroanatomist said:


> I hate it, because it locks on fast, stays locked on, and delivers sharp shots consistently, and that fact combined with the 12 fps frame rate means a harder time triaging my images.



*sigh*...what I would give to have your problems. ;P



neuroanatomist said:


> Seriously, though - in a burst from the 7D, I could always count on throwing away a few frames as OOF without even looking at them more magnified than reduced to fit my monitor (which is at least a 17" MBP at 1920x1200, and at best a 27" Apple Thunderbolt Display at 2560x1440). With the 1D X, they are almost always all in focus.



Aye. I have the exact same problem with the 7D. Granted, the 7D is a hell of a lot better and more capable than any other AF system I've ever used, but when it misses, it really misses. That tends to be really bad for BIF, as that can mean a lot of misses in sequence. I'd love to get my hands on a 1D X though...the 61pt AF, RGB metering, and dedicated AF/metering processor...that would just be amazing.


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## LetTheRightLensIn (Oct 16, 2012)

dtaylor said:


> elflord said:
> 
> 
> > You keep repeating it, but it's still wrong. It's wrong because the low end of the dynamic range is determined by SNR, and SNR changes when you downsample.
> ...



Maybe you should learn to be more of a geek before you start calling names while at the same time getting everything you are talking about wrong....


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## LetTheRightLensIn (Oct 16, 2012)

jrista said:


> The only way to discuss sensors _objectively_ is to reference actual measurements. From the outcry of the D800 fanatic, one would think it actually had a really crappy sensor by the way they demand images be normalized in size to allow the only form of objective comparison a study of a sensor could possibly endure. Ironically, the D800, D600, and D7000 all still outperform Canon sensors when you only look at the objective sensor measurements, so the inane debate about Print DR and its subjectivity is really just that...inane.



So you would compare noise energy at two different frequencies as if they were the same frequency???

You can go on and on page after post about this but you are just not getting this right at all.

How about this, since you hate downsampling so much and are not getting it, try thinking about this, how about you keep the D800 at 36MP but filter out all noise at higher frequency than 22MP and then compare then? Now that would make it fair right (strictly speaking if you went to complex NR you could make the higher MP actually do better, but then it gets hard to judge since judgement on what sorts of adaptive NR is good, etc.)? Think about it that way then.


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## dtaylor (Oct 16, 2012)

RLPhoto said:


> You must have never used the sheer awesomeness of the canon 61-Point AF system And yes, I've used nikons excellent 51-point system as well. So yes, I can say the Canon AF system is better than nikons right now. Plus, I never said that point count makes a better AF system, because then S0&y would be the best then. :



My apologies for assuming that your judgement was based merely on AF point count. I read that into your statement and it was not warranted.


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## dtaylor (Oct 16, 2012)

elflord said:


> > Try this: shoot 4x5 Velvia. Drum scan it. Down sample to 10 MP. Did you all of a sudden gain 3-4 stops of shadow detail? No? Hmmm...
> 
> 
> 
> ...



The second test is irrelevant because measuring the black point is not the same as measuring the floor of useful photographic detail. Assuming that it is leads to flawed extrapolations, such as DxO's 'normalized' DR graphs, or 9-stop scanned LF Velvia.


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## dtaylor (Oct 16, 2012)

jrista said:


> Aye. I have the exact same problem with the 7D. Granted, the 7D is a hell of a lot better and more capable than any other AF system I've ever used, but when it misses, it really misses. That tends to be really bad for BIF, as that can mean a lot of misses in sequence.



You've probably played with this, but...for BiF have you set AI Servo Tracking Sensitivity to the fastest setting? I don't achieve or expect 100% for BiF with the 7D. But I don't seem to have sequences of dramatic misses either. It's usually one or two more subtle misses out of a sequence.


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## dtaylor (Oct 16, 2012)

LetTheRightLensIn said:


> Maybe you should learn to be more of a geek before you start calling names while at the same time getting everything you are talking about wrong....



Well...I see from the down sampled 4x5 Velvia scan you attached that I was wrong.

OH WAIT. You didn't attach one ;D


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## jrista (Oct 16, 2012)

dtaylor said:


> jrista said:
> 
> 
> > Aye. I have the exact same problem with the 7D. Granted, the 7D is a hell of a lot better and more capable than any other AF system I've ever used, but when it misses, it really misses. That tends to be really bad for BIF, as that can mean a lot of misses in sequence.
> ...



I don't use the fastest setting, usually the middle or slightly fast setting. Too fast, and tracking jumps the moment an obstruction passes in front of the bird, which I don't like.


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## jrista (Oct 16, 2012)

LetTheRightLensIn said:


> jrista said:
> 
> 
> > The only way to discuss sensors _objectively_ is to reference actual measurements. From the outcry of the D800 fanatic, one would think it actually had a really crappy sensor by the way they demand images be normalized in size to allow the only form of objective comparison a study of a sensor could possibly endure. Ironically, the D800, D600, and D7000 all still outperform Canon sensors when you only look at the objective sensor measurements, so the inane debate about Print DR and its subjectivity is really just that...inane.
> ...



Yes, if that is how you want to put it. To put it another way, I want to compare the true RAW, native output of two cameras, untainted by software algorithms. Software algorithms introduce a level of abstraction in the results, and algorithms have the potential to introduce bias into the results. I am also not interested, really, in "comparing noise energy". Noise is only one aspect of IQ, and generally speaking a minor aspect of IQ. Normalization is NOT a necessary process in order to compare sensors. Ironically, even in the ABSENCE of normalization, Sony Exmor sensors STILL come out on top...and THAT is what matters to me. That tells me that Canon's latest sensors, despite their significant pixel size advantage, does indeed need to take care of their read noise and pattern noise issues...I didn't need some bias-introducing unknown software scaling algorithm and a quirky scoring system to tell me that in an exaggerated fashion. It was clear as day regardless of whether you "normalize noise frequencies". 



LetTheRightLensIn said:


> You can go on and on page after post about this but you are just not getting this right at all.



You can tell me...and Neuro, and dozens of other intelligent people on these forums...that same thing till the cows come home. Just because you, LTRL, insist that we aren't getting something doesn't make it true. We ALL know exactly where you are coming from, and why you insist on normalization. To be simple: we all reject your opinion just as much a you reject ours. And that opinion is that there is more to sensors and sensor comparison than doing so on a noise-normal baseline. There is far more information and knowledge to be gleaned if you examine the RAW, native hardware results for _true measurements_ in addition to normalized results, especially if you do not unduly weight the normalized results over direct measurements. One has to recognize that normalization introduces some level of bias regardless of how it is done, and that it is not the single supreme test that tells you everything about a sensor (particularly the way DXO does it, which explicitly overweights "Print" results in their scoring system.)


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## NormanBates (Oct 16, 2012)

Neuro is a very knowledgeable guy, and you're probably pretty bright too. And comparing noise at different resolutions makes no sense at all.


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## MarkII (Oct 16, 2012)

jrista said:


> To put it another way, I want to compare the true RAW, native output of two cameras, untainted by software algorithms. Software algorithms introduce a level of abstraction in the results, and algorithms have the potential to introduce bias into the results.



Unfortunately there is not really any such thing as a 'true measure'. Probably the closest would be simply to list the every single sensel value - all 20+ million of them, for a range of different inputs. There would be no algorithmic tainting, but equally no way to make sense of the numbers, let alone to make meaningful comparisons. And people would still complain that the original input scenes that were photographed were wrong somehow.

Like it or not, software algorithms are inherent in photography. Every time that you compress a JPEG you are using a proprietary and usually not-publically defined algorithm. Just the process of displaying the image on a monitor or rendering it on a printer involves hundreds if not thousands of such algorithms.

The figures that sites like DXO publish are fairly standard measures in engineering and use very standard and well understood algorithms. Although the final scores are obviously subjective, the actual measurement graphs are quite objective and use reasonably well defined measurements and algorithms - certainly compared to anything you see from Canon or Adobe.

Of course a single noise figure does not give the entire story about a sensor (banding, for example), and DXO likely measure/analyse a whole lot more as part of developing their RAW converters. Thankfully, they do not publish these. Imagine the debates if they published noise spectra for sensors to quantify banding, for example.


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## jrista (Oct 16, 2012)

NormanBates said:


> Neuro is a very knowledgeable guy, and you're probably pretty bright too. And comparing noise at different resolutions makes no sense at all.



Were not comparing noise, though. IMAGE quality...not NOISE quality...IMAGE quality. An image constitutes far more than noise. And, for that matter, one cannot observe more than 10 stops at most, and 8 stops on average, of DR on a computer screen anyway. Trying to say one can objectively "see" more DR in a D800 image scaled down to 8mp vs. at its native 36.3mp is naive. If you have a computer analyze the information contained in an image, and it tells you "Well, yes sir, your 8mp image has an additional 1.2 stops of DR!", that may make you feel better, but it doesn't change how you OBSERVE the quality of the image on your screen. If your the type that likes bragging rights...well, you would definitely have those too, as a single, subjective, scalar quantity to simply beat all your rivals over the head with when you and your buddies get together and start debating who has the better 8mp image. 

I would also strongly offer that too much shadow pushing generally results in some funky-looking results. There are dozens of extreme shadow lift examples posted on DPReview forums, as well as elsewhere. The only ones that look good are those that only perform modest shadow lifting. When you see three, four, six stop shadow lifts the results tend to look like one of those poorly tone-mapped HDR images from the earlier days of PhotoMatix, with bad tonality and poor color fidelity in the shadows.

Additionally, on the notion of shadow pushing. Having extra DR _in post_ is really about that...pushing shadows around without running into _unsightly_ noise. First, I won't deny Canon has unsightly read noise at ISO 100 (and to some degree ISO 200). They need to fix it, no question. My arguments have always been about DXO's Print DR ratings though, and the notion that you gain unbounded amounts of DR by downscaling. In the case of the D800, you can supposedly gain more DR than would be allowed by a 14-bit ADC's quantization. Let's assume we can, and we scale a 36.3mp D800 image down to 8mp and save as a TIFF. 

The moment you moved from RAW to TIFF, you lost the very vast majority of the exposure pushing power you had. Ever tried to push around a TIFF even by a moderate amount, let alone four or six stops? The results are far from pretty. You MAY, mathematically speaking, gain additional DR by downscaling...but it won't be as usable as the native hardware DR you had in the original RAW. Pushing about RGB triples rather than scalar native pixel values, imposes significant limits. Mathematics aside, realistically, regardless of how much you normalize Gaussian (photon shot) noise (which I think needs to be called out as distinct from read noise, which exhibits in very different ways and may not "normalize" the same way), downscaling changes the entire nature of your photos pixel structure. The results might look less noisy in the shadows, the remaining detail might be cleaner and sharper, but you lost some key things in the process. The photo is no longer RAW, you no longer have all that extreme post-processing latitude you once had, and you lost a CONSIDERABLE amount of original full-size detail.

Taken out of context, reading DXO's results, one might think the D800 was capable of 14.4 stops of DR strait out of the box at native size, and that all of that extra DR would be clearly observable on screen and usable during post-processing...and that everything is as blissful and perfect as it can get. I just want to put things into the proper context so we can have an objective discussion about sensor performance in the real world. The only way I know how to do that is to refer to _direct measurements_ of a sensors _actual hardware capabilities_, regardless of how much noise there might be. 

Out of the box, the D800 is capable of 13.2 stops of DR without clipping highlights or blocking shadows, that DR would give a user more leeway to push exposure around at native size as an ISO 100/200 RAW file than, say, a 5D III. Ironically, despite the fact that I've "unfairly" compared the D800 to the 5D III at a hardware level...the D800 still wins. Noise frequencies not withstanding.


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## jrista (Oct 16, 2012)

MarkII said:


> Although the final scores are obviously subjective, the *actual measurement graphs* are quite objective and use reasonably well defined measurements and algorithms - certainly compared to anything you see from Canon or Adobe.



You just hit the nail on the head, though. The "actual measurement graphs" (Screen Statistics) are indeed quite objective, and that has always been my point. I'll happily use the DXO Screen DR measurement to compare the hardware capabilities of sensors. The argument against my point is that DXO's measurements are useless as mechanism of comparing sensors because they were not taken from normalized images. I believe that notion is fundamentally wrong.


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## elflord (Oct 16, 2012)

dtaylor said:


> elflord said:
> 
> 
> > > Try this: shoot 4x5 Velvia. Drum scan it. Down sample to 10 MP. Did you all of a sudden gain 3-4 stops of shadow detail? No? Hmmm...
> ...



It's completely relevant, because it goes to the heart of the question, should you or should you not normalize ? 

Suppose you do as you suggest, and scan at some resolution (say 40 megapixels), and then downsample to 10 megapixels. Just to make this simple, let's assume that it's some kind of test image like these transmission wedges you're so fond of. 

Then you, dtaylor, are responsible for assigning a dynamic range score to both images (the 10 megapixel image and the 40 megapixel image). 

Should the two images receive the same score or not ? 

If you think the two images should receive the same score, you need to normalize.

As for what point the "floor" is for "useful photographic detail", that's a whole other can of worms. Suffice it to say, you haven't built any kind of case for why using the black point is not valid.


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## elflord (Oct 16, 2012)

jrista said:


> You just hit the nail on the head, though. The "actual measurement graphs" (Screen Statistics) are indeed quite objective, and that has always been my point. I'll happily use the DXO Screen DR measurement to compare the hardware capabilities of sensors. The argument against my point is that DXO's measurements are useless as mechanism of comparing sensors because they were not taken from normalized images. I believe that notion is fundamentally wrong.



I think you're having trouble understanding some really fundamental concepts here, such as "objective", "hardware", and "measurement". 

Let me pose a question -- suppose hypothetically, you have a 40mpx sensor and a 10 mpx sensor. The 10mpx sensor has a higher dynamic range per pixel. You could reasonably ask the question, if I downsampled (traded resolution for dynamic range), would I have more dynamic range in the 40mpx image ?


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## elflord (Oct 16, 2012)

jrista said:


> Yes, if that is how you want to put it. To put it another way, I want to compare the true RAW, native output of two cameras, untainted by software algorithms. Software algorithms introduce a level of abstraction in the results, and algorithms have the potential to introduce bias into the results.



This is not about using an elaborate "software algorithm". It is simple averaging, or statistics. 



> I am also not interested, really, in "comparing noise energy". Noise is only one aspect of IQ, and generally speaking a minor aspect of IQ.



DxO's dynamic range screen score is *defined* in terms of signal to noise ratio in the shadows. So it's not a "minor aspect" when we are discussing dynamic range. 



> You can tell me...and Neuro, and dozens of other intelligent people on these forums...that same thing till the cows come home. Just because you, LTRL, insist that we aren't getting something doesn't make it true.



We've regressed a bit apparently. Didn't we agree just a few posts back that you could increase dynamic range by downsampling, because it reduces the level of noise and therefore affects the blackpoint ? 

As for Neuro, I discussed this extensively with him in this forum and while he pointed out that you can't really get more dynamic range than the number of bits in the ADC (this is far from obvious by the way), he has acknowledged that you can increase dynamic range by downsampling. 

I think it's a little dangerous citing the "conventional wisdom" as if it were canon (with a little 'c'). Until quite recently, I'd watch everyone here pile on with the DxO bashing, and no-one really questioned this. The fact that it's been the conventional wisdom here for a long time doesn't really substantiate it. 




> . And that opinion is that there is more to sensors and sensor comparison than doing so on a noise-normal baseline.



"Screen" dynamic range is also done using a "noise normal" baseline of sorts -- it's just that a different baseline is used (SNR = 0db per pixel, without adjusting for resolution)



> One has to recognize that normalization introduces some level of bias regardless of how it is done,



How does it "introduce bias" ? (and what do you mean by bias ?)


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## elflord (Oct 17, 2012)

jrista said:


> NormanBates said:
> 
> 
> > Neuro is a very knowledgeable guy, and you're probably pretty bright too. And comparing noise at different resolutions makes no sense at all.
> ...



You're really on the wrong side of your own argument for two (or more) reasons. One is that the "IMAGE" does not consist of a single pixel. The other is that NOISE is what defines the baseline (lower end of) DxO's dynamic range (both the screen and print scores). 

So it's nonsense to pretend that you can have a discussion about the relative merits of screen vs print DR and ignore noise. 



> Trying to say one can objectively "see" more DR in a D800 image scaled down to 8mp vs. at its native 36.3mp is naive



You're on the wrong side of this argument too. Suppose you have to assign a "score" to the downsampled image and the original image. Do you think both images should get the same score ? If so, you should normalize. If not, you shouldn't normalize.

The overall impression of dynamic range won't change (after all, you were going to view the two images at the same size anyway), but the per pixel dynamic range changes considerably. 



> If you have a computer analyze the information contained in an image, and it tells you "Well, yes sir, your 8mp image has an additional 1.2 stops of DR!", that may make you feel better,
> but it doesn't change how you OBSERVE the quality of the image on your screen.



Well that's the thing -- if you don't normalize, you will find that sensors with lower resolution have more "dynamic range" as defined by saturation point / black point, even though when you view the two images at the same size (not 100% crops) on your screen, they appear to have comparable dynamic range. 

As it's been explained, the choice of 8mpx as a "target" is arbitrary -- the point is to get everyone on the same playing field. The difference in dynamic range scores for two sensors does not change when you normalize to a different resolution. I also made the point that even though quantization puts a limit on your ability to get a darker blackpoint, it doesn't stop you making improvements at 5db, 10db, etc, so even if you hit the quantization limit, you do get an increase in usable dynamic range.


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## jrista (Oct 17, 2012)

elflord said:


> jrista said:
> 
> 
> > NormanBates said:
> ...



You are asking a different question than I am asking, which may be where the problem lies. I am not interested in how much dynamic range the "image" has, at native size or downscaled, where image in this case is a digitized two-dimensional matrix of RGB pixels. Images are virtual constructs, and they can be manipulated in near-infinite ways with software, trading detail for DR or the other way around, removing noise with deconvolution, etc.

The question I am asking is, what is the "sensor" capable of? At what point is shadow detail completely overpowered by the electronic noise in the circuit, and at what point do my whites start clipping? In the physical hardware? The sensor itself isn't scalable...you can't halve or double its resolution or pixel pitch...it is a fixed construct. If you pointed the D800, the physical device, at a test display containing something meaningful...a person, a landscape, whatever, with 14.4 stops of DR...according to DXO's Screen DR results...it will fail to capture all of the DR in that scene. The sensor is capable of 13.2 stops, so 1.2 stops worth of DR are going to be lost somewhere. It will be lost either entirely to noise, or entirely to clipped highlights, or some ratio to both. 

Lets assume, for the sake of discussion, that you take a photo anyway. Let's say you expose to preserve the highlights, right up to the limit (so the brightest swatch in your test scene is exactly at maximum saturation.) You've lost a lot of dynamic range not to "noise"...that is too general a concept. There are a variety of types of noise. So lets be specific...you've lost a lot of dynamic range to "electronic noise" that is present in the sensors electronic circuit, which interferes with shadow detail. When you actually expose, and convert the image present in the sensor as charge readings at each pixel via the ADC, you are permanently losing a certain amount of the information that might potentially be recoverable from that read noise, and potentially losing or at least diminishing the rest of the information that might potentially be recoverable from that read noise. To be exact, about 0.4 stops (14.4 of our scene minus the 14.0 limit imposed by the ADC) worth of DR can be lost forever when the ADC digitizes the image, and 0.8 stops (14.0 clipping limit minus the 13.2 stops of DR the sensor is actually capable of) worth of DR will effectively be indiscernible from electronic noise...because it is either going to digitize a pixel that contains pure read noise, digitize a pixel that contains very low signal indiscernible from read noise, or digitize a pixel that contains a strong enough signal to differentiate it (even if only to a minuscule degree) from electronic noise. 

You probably won't lose ALL of that 1.2 stops to noise, but you'll lose most of it, especially if your electronic noise is as low as it is in the D800. The remainder, where you still have a very low signal that might be just electronic noise or might be actual signal information...well, you could never really know for sure which it was (at least in the case of a signal floor of 0db...in a Canon sensor that uses a bias offset, you probably could discern a fair bit of image detail that was below the bias offset, and effectively within the range of it's FPN and HVBN). Even if you convert the output RAW to TIFF and scale that TIFF image down to a quarter it's original size...you still aren't gaining back that information, it was digitized (i.e. hard coded, permanently registered, whatever you want to call it) as either useful information representing your scene or non-useful information that might be noise or might be scene detail. (As a matter of fact, your losing a lot more information than you originally lose to noise if you scale an image down that much, and while your black point might approach closer to zero, pixels that constitute the lower decibel of your signal won't be any more meaningful than they were before.)

Perhaps the argument just hasn't been made properly. It may be that dtaylor put it into better words than I, although I am pretty sure I've used the same terms and concepts he has in the past. Let me try to state it in different terms that might be more meaningful.

Dynamic Range as a simple score is generally meaningless. DR that might be gained in the process of downscaling an image, at least to me, still feels rather meaningless...I understand what you (elflord) are saying when you state "you can still gain at 5db, 10db, etc.)...but that is in relation to general noise caused by the random physical nature of light, and applies at all levels to all cameras. (Read noise, however, exists only in the shadows, and exhibits in a different way than photon noise, so the same simplistic averaging rules you apply to photon noise may not apply to less random forms of electronic noise.)

As a tool to gauge how much detail you WILL *NOT* LOSE to ELECTRONIC NOISE (vs. photon shot noise) if you expose a scene of known dynamic range with a sensor of known dynamic range, assuming you expose to maximize the retention of detail from the deep shadows to the brightest highlights...I believe such a DR measurement is very meaningful. That is what I refer to as Hardware DR, or what DXO calls Screen DR. It may be more accurately termed ADC DR, since it is really the ADC that imposes a limiting factor. Hardware DR tells you that even though your computer screen can only display 8 stops worth of DR when rendering your photos, if you exposed properly, you could push around about _five point two_ additional stops worth of useful detail-retaining information (assuming D800), and "recover" information that otherwise might simply look like pure black or pure white on your screen. 

Either way...once your otherwise fluid and easily redistributable image signal on the sensor hits the ADC, the non-discrete or effectively "analog" signal is quantized, potentially "recoverable" detail (i.e. if you change exposure via shutter speed or aperture) well below the noise floor is permanently lost as the electronic noise in each pixel is permanently recorded, and no amount of post-processing will _recover_ what you lost (although if what you call a gain in DR is simply making black pixels blacker and/or white pixels whiter, regardless of whether doing so actually increases the amount of meaningful information those pixels contain...I guess thats something...)

Well, either you understand that, or you don't. Either way, these conversations (in multiple threads) have gotten well out of hand, and I don't want to keep contributing to that. So I'm out.


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## tron (Oct 17, 2012)

After elford's excellent description -for which I thank him again - I can accept the increase in DR when downsampling.

I will also accept that Nikon has greater DR but we have to think of it either as a 36Mpixel camera with 13.2 stops DR or a 8 Megapixel camera with 14.4 stops DR (which makes it practically a different camera, otherwise someone would downsample to what 2Mpixels? Wouldn't that increase DR to say ... 15 stops?)

It is NOT a 36Mpixel camera with 14.4 stops DR at max resolution (we cannot have the cake and eat it!) So if we want to think of D800 for what it is mainly (a 36Mpixel camera) we have to think of it as a 13.2 stop DR camera. (This does not reduce the DR capabilities of D800 of course). 

P.S Too much trouble and fights. What is a 1.2 stops difference in DR between forum members?


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## verysimplejason (Oct 17, 2012)

tron said:


> After elford's excellent description -for which I thank him again - I can accept the increase in DR when downsampling.
> 
> I will also accept that Nikon has greater DR but we have to think of it either as a 36Mpixel camera with 13.2 stops DR or a 8 Megapixel camera with 14.4 stops DR (which makes it practically a different camera, otherwise someone would downsample to what 2Mpixels? Wouldn't that increase DR to say ... 15 stops?)
> 
> ...



I had fun reading all these replies. At least its an education of some form though I can't really see the effects of these things in my usual photography. I must not be harnessing my camera enough. I need to shoot more. Let's shoot more. ;D


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## elflord (Oct 17, 2012)

tron said:


> After elford's excellent description -for which I thank him again - I can accept the increase in DR when downsampling.
> 
> I will also accept that Nikon has greater DR but we have to think of it either as a 36Mpixel camera with 13.2 stops DR or a 8 Megapixel camera with 14.4 stops DR (which makes it practically a different camera, otherwise someone would downsample to what 2Mpixels? Wouldn't that increase DR to say ... 15 stops?)
> 
> ...



The intuition is about right though it's really best to think of it as 13.2/36mpx, and then think of 14.4/8mpx as where you'd go if you could extend the DR/resolution tradeoff all the way down to 8mpx. It's useful if you want to compare two cameras with different resolutions 

The full story is a bit thornier than that. You can't push the black point more than 14 stops lower than the saturation point, but you do keep getting cleaner shadows as you downsample (e.g. down to or even lower than 8mpx) which means more _usable_ DR


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## NormanBates (Oct 18, 2012)

This: http://xkcd.com/386/


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## tron (Oct 18, 2012)

NormanBates said:


> This: http://xkcd.com/386/


+100000 ;D


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## tron (Oct 19, 2012)

Mikael Risedal said:


> tron said:
> 
> 
> > P.S Too much trouble and fights. What is a 1.2 stops difference in DR between forum members?
> ...


Ok, then continue fighting ;D ;D


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## Woody (Oct 19, 2012)

I am surprised it's been more than a week since DXO Lab announced their software support for 1DX and D600 but there has been no official release of their 1DX test results, unlike the D600. Is this because (i) DXOMark do not believe their results and are now re-testing everything (ii) they are blackmailing Canon to give them more monetary support (iii) they are blackmailing Nikon to grant them more support.

;D ;D ;D


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## rpt (Oct 19, 2012)

Woody said:


> I am surprised it's been more than a week since DXO Lab announced their software support for 1DX and D600 but there has been no official release of their 1DX test results, unlike the D600. Is this because (i) DXOMark do not believe their results and are now re-testing everything (ii) they are blackmailing Canon to give them more monetary support (iii) they are blackmailing Nikon to grant them more support.
> 
> ;D ;D ;D


Or *all of the above* with special focus on #2 and #3...


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## AmbientLight (Oct 19, 2012)

From a pure business perspective you sure got a point here .


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## rpt (Oct 19, 2012)

AmbientLight said:


> From a pure business perspective you sure got a point here .


Shoot! I thought I was being pessimistic...

 It has been a long time that I have been in software - A REALY LOOOOOOOOOONG time (for me at least...). The phrase "to err is human" did not just spring up. That was a program manager of a software firm may be 4000 or so years back realized that it was "money for nothing, bugs for free"!


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