# 5D3 same max dynamic range as the 5D2???



## LetTheRightLensIn (Mar 9, 2012)

Assuming the side masking area can be used for the measurement then:

Same DR for 5D3 and 5D2 is what I get. Zero improvement for ISO 100 DR. 
Wow I had really expected a big improvement. Canon still had a lot of room there to get better.

I think the D800 will quite a lot more maximum dynamic range unless they really messed up the D7000/D3x->D800 Exmor transition.

I just hope that it will turn out the side masking area on the 5D3 images is not valid for this purpose (the top masking area definitely appears to be invalid for this purpose with the 5D3, I just hope same can be said for the side, but it doesn't really look like that will be the case).


On a side note, the SNR might be 1/2 to 2/3rd stops better than the 5D2 though, but that is based off of using ACR which is a sketchy way to compare. High ISO banding appears to be cleaned up on the 5D3 compared to the 5D2, if so and if it is 2/3 better SNR than that is a pretty decent improvement on the high end, but I wonder if Canon has the tech to improve ISO100.


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## XanuFoto (Mar 9, 2012)

How is the D800 selling? Have they have more preorders then the 5D mkIII?


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## LetTheRightLensIn (Mar 9, 2012)

XanuFoto said:


> How is the D800 selling? Have they have more preorders then the 5D mkIII?



I have no clue.


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## Astro (Mar 9, 2012)

LetTheRightLensIn said:


> XanuFoto said:
> 
> 
> > How is the D800 selling? Have they have more preorders then the 5D mkIII?
> ...



guessing from amazon.. the 5D MK3 was way ahead of the D800.


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## LetTheRightLensIn (Mar 9, 2012)

Actually I did find a way to begin to compare the low ISO banding between the 5D2 and 5D3 and maybe has been improved.

So even though the measured dynamic range is the same , the usable amount might be very slightly to somewhat better than on the 5D2 since the deep shadows seem as if though they will not have as much nasty cross-hatching. I haven't quantified how much yet. And I really would need a full black frame from the 5D3 anyway.

The far edge on the 5D2 also has less fixed pattern banding so it might not be fair to compare the far left masked edge of the 5D3 to the center of the 5D2 frame. Doing that, the 5D3 appears to have noticeably less banding, but trying to compare just the edge it looks much closer. So too early to say for sure. I could see it having anywhere from just slightly (almost meaninglessly less) to considerably less.


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## LetTheRightLensIn (Mar 9, 2012)

Astro said:


> LetTheRightLensIn said:
> 
> 
> > XanuFoto said:
> ...



Maybe, maybe not but that has nothing to do with how the sensor performs. What in the world does it have to do with this thread? Is this the which camera is selling better thread? Which camera base has the most loyal fans?

If more people liked a sprinter other than Usain Bolt at the last Olympics does that mean that Usain Bolt was not the fastest??? It doesn't matter who has the best, most loyal, or most fans, that is a different matter entirely.

And once again, no I am not some Nikon fanboy. I have never owned a Nikon camera of any sort in my entire life.
I've owned many Canons. That doesn't mean I need to lie and make up BS to make myself feel better about Canon.

It's kinda sad that the fanboys here are so extreme that they just smite anyone and go la-la-la-la I can't hear you rather than look at facts. But go ahead, be my guest if you feel happier for doing it.


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## Astro (Mar 9, 2012)

LetTheRightLensIn said:


> It's kinda sad that the fanboys here are so extreme that they just smite anyone and go la-la-la-la I can't hear you rather than look at facts. But go ahead, be my guest if you feel happier for doing it.



maybe some here are just bored to see the all this guessing and wait until there are some facts worth to talk about?!


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## LetTheRightLensIn (Mar 9, 2012)

Astro said:


> LetTheRightLensIn said:
> 
> 
> > It's kinda sad that the fanboys here are so extreme that they just smite anyone and go la-la-la-la I can't hear you rather than look at facts. But go ahead, be my guest if you feel happier for doing it.
> ...



Fair enough, although this is getting to be more solid than guessing now.

Looking at it more, the side area appears to be valid, in which case my measurement will be valid. It's not like DxO will do anything different when they calculate DR they use the exact same procedure. I get pretty much same numbers for my 5D2 as they get for the 5D2. (keep in mind DxO pops up Print Plot which is normalized to 8MP and my figures above are not)

And this is the rumors part of the forum.


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## LetTheRightLensIn (Mar 9, 2012)

It is a sad state of affairs when presented with direct evidence people just stick their head in the hand and shoot the messenger if the results don't mesh with their hopes, internal belief system, what have you. And not just in this forum.

I present a careful and reasonable calculation that doesn't tell the story that all the little fanboys had expected (or that I had expected myself) and smite, smite, smite the messenger. ;D It kind of makes me laugh, in this context, talking about just cameras. In more serious realms the same sort of behavior is kind of sad though.

If I had made up numbers and said it had 3 stops better dynamic range than the 5D2 and 6 stops better than the D800 I'd probably have gotten +30 and tons of praise for being creative with the numbers to make big bad awful 5D2 or Nikon/Sony look bad.

While it seems to measure better for high iso performance, nobody has measured anything hinting at any better low ISO dynamic range. Seems we improved only on one side of the range. (and if you look at all the Canon press they kept talking about it being better.... at mid and high isos. I was hoping they just forget to mention improved low iso, but i guess they didn't mention it because they didn't do much there this time. at least the high iso stuff should be better though.)


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## 3kramd5 (Mar 9, 2012)

How do you calculate the DR performance of a sensor without information about the actual light characteristics of a scene? Isn't it an input/output game?

What's a masking area?

How can I compute the DR of my camera from a random image?


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## neuroanatomist (Mar 9, 2012)

LetTheRightLensIn said:


> It is a sad state of affairs when presented with direct evidence...
> 
> I present a careful and reasonable calculation...



Where, exactly, is this evidence you've presented? Looking above, I see none. Calculation? Aside from model numbers, the only numerical part of your statement is "zero improvement." 

If you'd like present a well-reasoned case, backed up by actual evidence, fine. Else, it's just opinion and hot air. I don't shoot messengers who bring bad news, as long as that news is accurate. But an unsupported (and knowingly inflammatory, at that) conclusion deserves the bullet.


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## unfocused (Mar 9, 2012)

neuroanatomist said:


> LetTheRightLensIn said:
> 
> 
> > It is a sad state of affairs when presented with direct evidence...
> ...



+1000000000

I know I'm not the most technical-minded person, but I have no 'effin clue what this is all about. Is the "side masking area" a real thing? Does the OP actually have the camera in-hand? Is this some theoretical calculation based on published specifications? And, before you accuse me of being a "fanboy" (whatever the heck that is supposed to be other than just a schoolyard taunt) I don't even care about the 5D III. It's not in my budget and I don't intend to buy one. I don't even care about full-frame for that matter. I just enjoy trying to learn some things, but this doesn't seem like anything but some goofy troll.


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## LetTheRightLensIn (Mar 9, 2012)

neuroanatomist said:


> LetTheRightLensIn said:
> 
> 
> > It is a sad state of affairs when presented with direct evidence...
> ...



Load the RAWs into IRIS (it recognizes 5D2 files completely and masks off their masking area so you need to use a black frame from the 5D2). For the 5D3 select a big chunk of the left masking area (the top masking area appears to have some data or something stored in it and won't work) and hit the statistics option. You find that the avg value is 2048 and that is the black level. You then see a standard deviation of about 5.95 or so (I was actually a little generous if anything since a patch higher up that I sampled said 6.0). Then you draw a box around the blown highlights in one of the IR ISO 100 images and notice that the raw saturation level at ISO 100 is 15283. 

With those three numbers you do this Log[2] ((15283-2048)/5.95)) and get 11.1 stops.

For the 5D2 you find values 15760,1024,6.1 and get 11.2 stops.

banding looks worse on the 5D2 black frame but it's hard to compare to the tiny area of the 5D3 masking, the 5D3 looks to have noticeably less banding there, but the area is too small to really be able to much for sure, it shows promise, but it remains to be seen.

You can set the pop theshold and base values to a narrow range around 1024 for 5D2 and 2048 for the 5D3 to get a good look at the dark current banding and noise characteristics between the two in a fair way (other than nobody has provided a 5D3 black frame so the area is too small to be able to count as representative, the banding might show up more if you got to see a large chunk of the main area).

The masking area that I talk about is the portion of the sensor that does not get exposed to light but that does get recorded to the RAW files, the actual RAW files are slightly larger dimension than the exposed area size that most people are familiar with. The top masking area is unfortunately not quite as large as would be helpful to better aid RAW converters in removing banding.

Anyway, that is how I did it.
On DPR some others have also done it (using different software in some cases) and they got the same things to a tenth of a stop or two.

There is always a chance that the masking area will not match the main area, but looking at it more closely I see no sign of anything weird in the left masking area and I would be surprised if it turns out to not be representative. I hope I am wrong though since who wouldn't want the real result to shot a stop or two improvement here.


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## t.linn (Mar 9, 2012)

neuroanatomist said:


> If you'd like present a well-reasoned case, backed up by actual evidence, fine. Else, it's just opinion and hot air. I don't shoot messengers who bring bad news, as long as that news is accurate.



There's actually a number of long threads over at DPR regarding the issue of banding at low ISOs on Canon's post-1D3 sensors. It was a well documented problem with 5D2's and it appears to be resolved in the horizontal direction but unaddressed in the vertical on the 5D3. One discussion is here:

http://forums.dpreview.com/forums/readflat.asp?forum=1032&thread=40825115&page=1

Folks can rightly quibble that the comparison between the two images is invalid because conditions were not equivalent but you can't deny that the banding still exists. The bottom line is that the analog design of the Canon sensor significantly limits the DR of Canon DSLR's at low ISO. The Sony sensors have a more modern design that completely eliminates this phenomenon. Check out the detail Horshack is able to pull out of the shadows on this D7000 image. It's worth noting that the pixel pitch of the D800 is about the same so anyone thinking that image quality is going to be lousy at 36 megapixels had better take a look.

From the DPR forum (same thread as above, p7):



> To address those that believe any image whose shadows are raised this much would otherwise be unusable even without banding, here is a D7000 single exposure, exposed for the highlights near the sun, with the shadows raised in LR3 w/fill light +100 plus a +1.17 stop GND additional shadow push for the foreground.
> 
> Naturally there is noise in this image from lifting the shadows...but there is still lots of detail and color retention, and this is the full 16MP. It generated a rather nice 8x10 print.
> 
> ...


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## t.linn (Mar 9, 2012)

t.linn said:


> Check out the detail Horshack is able to pull out of the shadows on this D7000 image. It's worth noting that the pixel pitch of the D800 is about the same so anyone thinking that image quality is going to be lousy at 36 megapixels had better take a look.



Shoot! The links are down now. I don't know if that's temporary or not. I looked at the before and after yesterday and felt quite envious of Nikon owners who are able to recover impressive shadow detail out of total darkness. I've tried that with my 5D2...and recovered banding. :


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## 3kramd5 (Mar 9, 2012)

LetTheRightLensIn said:


> Load the RAWs into IRIS (it recognizes 5D2 files completely and masks off their masking area so you need to use a black frame from the 5D2). For the 5D3 select a big chunk of the left masking area (the top masking area appears to have some data or something stored in it and won't work) and hit the statistics option. You find that the avg value is 2048 and that is the black level. You then see a standard deviation of about 5.95 or so (I was actually a little generous if anything since a patch higher up that I sampled said 6.0). Then you draw a box around the blown highlights in one of the IR ISO 100 images and notice that the raw saturation level at ISO 100 is 15283.
> 
> With those three numbers you do this Log[2] ((15283-2048)/5.95)) and get 11.1 stops.
> 
> For the 5D2 you find values 15760,1024,6.1 and get 11.2 stops.



So... what are you doing? Blowing the highlights and measuring, blowing the shadows and measuring, and computing the magnitude between them? If you repeat the same calcs for every 5D3 sample do you get the same thing? If you repeat for every 5D2 image do you get the same 11.2? Or are you just measuring the DR of a single image?

How do you explain the difference between your 5D2 numbers and DXO's who measured it using hardware (known lighting values and a variety ND filters to stop the light down in known intervals) and determined a maximum sensor potential DR of 11.9?

I don't have a dog in the fight, just trying to understand the calcs and whether they are repeatable and meaningful.


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## wockawocka (Mar 9, 2012)

I've never seen banding on my files unless I've screwed up the exposure and have had to push the image.

It doesn't surprise me that dynamic range hasn't improved either. I mean, there are some drawbacks to using a CMOS sensor. Until they change the sensor type there will always be limits.
They could use a CCD sensor but then they'd be limited to a max ISO of 1600, but you'd get 12 stops of range.


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## Curmudgeon (Mar 9, 2012)

LetTheRightLensIn said:


> And once again, no I am not some Nikon fanboy. I have never owned a Nikon camera of any sort in my entire life.
> I've owned many Canons. That doesn't mean I need to lie and make up BS to make myself feel better about Canon.
> 
> It's kinda sad that the fanboys here are so extreme that they just smite anyone and go la-la-la-la I can't hear you rather than look at facts. But go ahead, be my guest if you feel happier for doing it.



As a matter of principle, I never use that silly applaud/smite button, but if I did you'd get a +1 for figuring out a preliminary way to get a reading on the 5D3's dynamic range. I find that there's a lot of useful information to be gleaned from many people on this forum--too bad it has to be filtered out from a noisy minority who take personal offense to anything other than praise for Canon.

Asking about the specifics of your methodology is legitimate. Crowing about the 5D3's early sales performance is indeed irrelevant.

On another thread about the pricing of the 5D3 I made the point that the sales domination of the 5D2 over competing full frame models depended largely on its prowess as a video camera. I then noted that a number of leading videographers--including Vincent LaForet--were already on record as being unimpressed by the video features of the 5D3, and that the disappointment of this important market segment might translate to lower-than-expected sales--which in turn might lead to a fairly quick drop in price.

I was assailed immediately. Laforet, it was explained, was a _nouveau riche_ photojournalist turned camera snob by his giddy success as a videographer. And then, having acknowleged LaForet's negative response to the camera by attempting to discredit him, my accuser turned on me and charged me with bias for saying that LaForet was unimpressed with the 5D3's specs. How many ways can you have it?

My point wasn't even about the merits of the camera; it was about the expectations of videographers and what that might do to sales. No matter. It could be construed as an indirect attack on darling 5D3 and needed to be struck down *immediately*.

The clear fact is that at least initially videographers are not embracing the 5d3 the way they did the 5D2--it's all over the Internet. And the equally clear fact is that Canon cameras have a number of class-leading qualities but they have a problem with dynamic range compared to Sony/Nikon. Photographers know it. On the eve of the introduction of the 5D3, when all of the talk should have been about megapixels and frame rate, etc., this forum sprouted a 5-page thread of people worrying that Canon might not have addressed the problems of dynamic range. Likewise,all the testing organizations find that Canon underperforms in this area. How are we going to explain that away? DPR and DXO rig their tests because because Sony/Nikon own a controlling interest in them?

And while nothing is definite yet, there are reasons to wonder if Canon has been able to improve the performance of the 5D3 in this area. The company would have to be deaf and blind not to know that its customers are worried about this issue. And yet we've heard a lot of talk about the improved SNR, two-stop better high-ISO performance in jpeg, as well as the multi-frame HDR feature, but not a single official claim that I can find about an actual increase in dynamic range. DR is important to my kind of photography and I am increasingly concerned that either Canon's engineers can't figure it out or that Sony holds some patents that Canon can't circumvent.

But raise the possibility that Canon has a problem in this area and you're a troll. Any questioning of Canon's perfection is construed as a personal attack. I'm thinking what's needed is a banner--24 pt bold--across the top of every page in this forum: *A reminder: the latest scientific evidence confirms that there is absolutely no correlation--repeat, absolutely NO correlation--between your choice of camera equipment and the length of your phallus.*


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## LetTheRightLensIn (Mar 9, 2012)

3kramd5 said:


> LetTheRightLensIn said:
> 
> 
> > Load the RAWs into IRIS (it recognizes 5D2 files completely and masks off their masking area so you need to use a black frame from the 5D2). For the 5D3 select a big chunk of the left masking area (the top masking area appears to have some data or something stored in it and won't work) and hit the statistics option. You find that the avg value is 2048 and that is the black level. You then see a standard deviation of about 5.95 or so (I was actually a little generous if anything since a patch higher up that I sampled said 6.0). Then you draw a box around the blown highlights in one of the IR ISO 100 images and notice that the raw saturation level at ISO 100 is 15283.
> ...



The 11.9 from DxO is for their 8MP print normalized plot. Since the 5D2 and 5D3 have the same MP I didn't normalize them against each or anything else. If you normalize my 5D2 numbers then you get 3.8 normalized read noise and match DxO's 8MP normalization value 11.86 vs 11.9. Also note if you hit the screen button on their chart, non-normalized values, then they happen to list the exact same 11.2 dynamic range I listed above.

Also here is a guy who made a comparison tool, he does things a bit differently so his charts don't quite match others entirely but they fit the same general pattern:
http://home.comcast.net/~NikonD70/Charts/PDR.htm

Segue to:
Some other data he has also appears to hint at a 1/2 to 3/4 stop improvement for 5D3 vs 5D2 high ISO performance, same ball park as most seem to be estimating for that.


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## 3kramd5 (Mar 9, 2012)

Thanks for trying, but can you dumb it down? How does resolution affect DR?


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## LetTheRightLensIn (Mar 9, 2012)

wockawocka said:


> I've never seen banding on my files unless I've screwed up the exposure and have had to push the image.
> 
> It doesn't surprise me that dynamic range hasn't improved either. I mean, there are some drawbacks to using a CMOS sensor. Until they change the sensor type there will always be limits.
> They could use a CCD sensor but then they'd be limited to a max ISO of 1600, but you'd get 12 stops of range.



it can be improved even for CMOS, D7000/D3x/D800 demonstrate this, they use a digital CDS and column parallel on sensor ADCs; apparently there are other ways too, one person claims Canon was offered one but didn't want to bother; the exmor method may be patented

the 5D3 should have similar DR to the D800 at ISO800 and above but lower at ISO 400 and much lower at ISO100-200, this is slightly speculative but pretty likely to bear out

high iso performance may be fairly similar between the 5D3/D4/D3s/D800 with the D4 perhaps taking the crown by 1/3 to 1/2 stop (meaningless to a modest difference), this is getting much more speculative now though but not unreasonable, in some ways the higher MP count of the 5D3 and D800 may make their files in some ways have a nicer looking high iso noise than the D4 and especially D3s perhaps, again that is a bit speculative


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## LetTheRightLensIn (Mar 9, 2012)

3kramd5 said:


> So... what are you doing? Blowing the highlights and measuring, blowing the shadows and measuring, and computing the magnitude between them? If you repeat the same calcs for every 5D3 sample do you get the same thing? If you repeat for every 5D2 image do you get the same 11.2? Or are you just measuring the DR of a single image?



I'm not doing anything. I'm using IR's files. Thankfully they blew the highlights on some specular highlights so that is where I got the raw saturation levels from. The dark current noise I measured from the masked area of the file that was cut off from light. it seems to be around +/- .1 stops for across three quick tries on files, doing the same thing my 5D2 values happen, by chance to match DxO exactly to the tenth. different copies might vary +/-.15 or so perhaps unless you got a real weird copy


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## etto72 (Mar 9, 2012)

I see many folks in this forum deducing and assuming from pictures that are floating on the web that the DR of the new 5D mk III will be about the same of the mk II
Before giving such a underwhelming pictures think a little..
From DP ratings:
5D - 9.2
1Ds mk III - 11.3 (5D mk II - 11.1)
1D mk IV - 12
5D mk III... ?
As you see there was a constant improvement with each sensor generation(Full frame and 1.3)
the last camera generation (1D mk IV) has 12EV and considering that the new 5D (and 1DX)have the latest technology and that the pixel size of the new cameras is bigger
I expect to see around 12.5-13EV
That would be awesome!
Cheers
Ettore


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## Curmudgeon (Mar 9, 2012)

etto72 said:


> I see many folks in this forum deducing and assuming from pictures that are floating on the web that the DR of the new 5D mk III will be about the same of the mk II
> Before giving such a underwhelming pictures think a little..
> From DP ratings:
> 5D - 9.2
> ...



That _would_ be awesome. Hope you're right. Can't help wondering why Canon would be keeping such performance a secret.


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## LetTheRightLensIn (Mar 9, 2012)

etto72 said:


> I see many folks in this forum deducing and assuming from pictures that are floating on the web that the DR of the new 5D mk III will be about the same of the mk II
> Before giving such a underwhelming pictures think a little..
> From DP ratings:
> 5D - 9.2
> ...



I was looking forward and expecting 12.5-13 too, but so far nobody has measured that. Five people have tried and all have gotten it to be about the same as for the 5D2. I just hope that by some miracle the IR got a really bum copy or something, not likely though. Or that the masked area is doing something different this time, not likely though either.

Also you are listed per pixel 100% view DR but if you look at normalized per same print/view DR then the 1Ds3 and 5D2 and 1D4 all have basically the same DR and there was no increase of near 11 to 12 for the 1D4, that is only because you were comparing the per pixel DR. Canon seems to have topped out in what they can do with their processes at ISO DR back with the 1Ds3 release.

I really thought that after so many years and keeping it at 22MP they would have a big break through this time. And when I saw the $500 more than the D800 for less MP then I really, really thought they would have the break through. Seems like not. I was actually horrified when I saw that first guy report the same read noise.  I couldn't believe it.

Only chance left is for the 1DX. (IMO it would really suck if they held some special new fab and process and tech for the 1DX only when the 5D3 is more of a landscape cam and could arguably use the DR more than the 1DX if anything)


at high ISO it will probably go up a trace, perhaps even a modestly noticeable 1/2+ stops, compared to the 5D2 and even more compared to the 1Ds3 and the SNR does appear to be nearly 2/3 stops better and the banding less so there are some improvements, but for 3.5 years and same MP and $500 more I thought they'd have a bit more, still it should be close to the best at high iso


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## parsek (Mar 9, 2012)

If the findings of these people [who have done their own DR tests] become verified truth, it is very disappointing performance by Canon. DR is the holy grail at this point in high performance digital imaging IMHO. Low light ISO performance being it´s younger brother.


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## jrista (Mar 9, 2012)

LetTheRightLensIn said:


> It is a sad state of affairs when presented with direct evidence people just stick their head in the hand and shoot the messenger if the results don't mesh with their hopes, internal belief system, what have you. And not just in this forum.



What *direct* evidence, man?? You've been regurgitating hearsay, speculation, unverifiable test images with no EXIF data, arguments from DPR between individuals who seem to have *long* reputations as promoting hearsay and speculation, oh, and a few secretive "tests" that ->you<- have done yourself using some kind of mysterious and questionable method to "measure" DR from a few random sample images (*WOEFULLY INADEQUATE* to the task of properly measuring DR) on the net...the very vast majority of which have been taken with PRE-PRODUCTION 5D III's.

I don't really know what your goal is here, but your just rumormongering and spreading hearsay. Nothing you have provided thus far is _verifiably_ factual, and there don't even exist any sample images on the net yet that could even be remotely considered adequate to properly "measure" dynamic range, let along start a little jihad against the 5D III and how its a step back from the 5D II in terms of noise _and_ DR. (Something which I think most of us who have looked at 5D III sample images can disagree with without even the need to do any sketchy testing...because so far the sample images have been nothing short of fantastic and very competitive (from an IQ perspective...subject wise, I often wonder who screwed Canon's head on, and why they screwed it on backwards.))

Its time to just wait for the darn thing to actually hit the streets, and let the institutions who have _solid reputations_ for accurately measuring these things *do their job*. Until then, its ALL JUST SPECULATION!


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## LetTheRightLensIn (Mar 9, 2012)

jrista said:


> LetTheRightLensIn said:
> 
> 
> > It is a sad state of affairs when presented with direct evidence people just stick their head in the hand and shoot the messenger if the results don't mesh with their hopes, internal belief system, what have you. And not just in this forum.
> ...



I listed my entire procedure in detail! I wasted like ten minutes typing it out. It's the same thing DxO does. A lead software developer for a RAW converter has done the same test and found the same thing. I gave you the link. Another guy has done the same thing and gotten the same results. I'm pretty sure I put that link in this thread too. PhDs, engineers, lead software developers, detailed procedure. What more do you want?

All you need to measure DR is an area of an image that is totally blown out and an area that is 100% black dark current and the IR files gives us that. Unless IR got a really, really bum copy or they suddenly started making the left mask area perform differently and I hope one or the other is the case but I doubt it, this is pretty much solid results.

My 'woefully inadequate' procedure only happened to match the DxO ISO 100 results for ISO 100 to the tenth of a stop (easily within any sample to sample variation, different parts of even a given sensor can easily be +/- 0.1 difference alone). 

Smite away, have fun, whatever.

I hope we are wrong and that the pre-pro unit they got stinks or that they messed with the masking area. Every time we hoped that in the past it didn't turn out to be the case, but I hope this time it will. It's not at all likely. But if I (we) are wrong I'll be jumping for joy.

At least the high ISO should be some degree of better even if not the low.


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## jrista (Mar 9, 2012)

LetTheRightLensIn said:


> jrista said:
> 
> 
> > LetTheRightLensIn said:
> ...



Does your method involved the use of a specialized test device designed just for the purpose of testing DR, that is finely calibrated to produce consistent test images containing tonal swatches of exact known intensities, lit by a very specific kind of light bulb that is capable of emitting a very specific amount of light, with a very specific color balance, at a very specific intensity? Do you take dozens of sample shots of said test device, evaluate each individual shot to produce very accurate measurements into a data sample set? Do you aggregate the measurements of that data sample set to produce a scientifically accurate mean, standard deviation, ratios, etc.? Do you have your results verified by multiple parties for accuracy? Is your final conclusion based on those verified results? Are all of your test cases for every brand of equipment you test subjected to the EXACT SAME TEST, done in the EXACT SAME WAY, to minimize deviation between the results of various brands, models, and even samples of specific equipment? Do you have a reputation as someone who does these things...a track record of verifiable accuracy?

DXO doesn't just take a sample image and perform some little procedure on it to come up with the dynamic range numbers they publish. Claiming that your results are as accurate as theirs comes with a certain responsibility, and I'm sorry...but you repeatedly claiming that your as accurate and reliable as DXO, well its actually rather sad at this point. As it stands, all we really have at this point is your personal word...but someones word only has meaning to those who have reason to trust it.

You've done some "fiddling", and you have your personal conclusions. As far as I can tell, this supposed "engineer" your a fan of has also done some "fiddling", and also has his own personal conclusions. Speculation and hearsay, but personal conclusions nevertheless. You've been repeating your conclusions all over this forum for a few days now. Its certainly your prerogative to continue, but personally, I would stop comparing my own little home-grown, ad-hoc DR evaluation method to the precision testing performed by DXO...save yourself a little face. 

We all know what your opinion is, and I think most of us are content to admire the IQ of the images we've seen so far as being a a competitive improvement over prior Canon cameras, comparable to the competition at the very least...and wait for *reputable* institutions to provide accurate details about DR, ISO, noise, color fidelity, etc. once these cameras actually hit store shelves.


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## meli (Mar 9, 2012)

Somehow i doubt you would be so sensitive about its methodology and findings if LetTheRightLensIn's thread title was "Zomg 5d3 has 14DR u guys!"

In my case i tend to believe him; his approach -with the amount of data we have so far- seems reasonable, his results fits other people tests, and since Canon itself hasnt bothered to announce something about low iso performance, tends to point in the direction LetTheRightLensIn is.


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## moreorless (Mar 9, 2012)

Curmudgeon said:


> That _would_ be awesome. Hope you're right. Can't help wondering why Canon would be keeping such performance a secret.



Perhaps similar to the pixel binning issue on video? in order to hype it on one product you need to trash your other products.

In areas such as AF and FPS many users simpley don't need them and ISO tend to be hyped by max numbers rather than pointing out the weakness of lesser models at similar levels. DR and video quality on the other hand are issue that relate to most users and talking openly about weaknesses probabley isnt something there keen on.


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## altenae (Mar 9, 2012)

We are all spending hours and hours on numbers. 
Very sad. Very sad. 

Some time ago I saw an image taken from a MF and I was blown away. 
I checked dxo and the DR was worse than the Sony Nex 10. 

There are two things :
Numbers and what your eyes see. 

I am going out now to take some pictures. 
Or should I stay home to do some more calculations. 

Please guys use the camera for where it was made for. 

Nice article hereeyes vs. numbers)

http://www.luminous-landscape.com/essays/eyes-vs-numbers.shtml


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## neuroanatomist (Mar 9, 2012)

LetTheRightLensIn said:


> I listed my entire procedure in detail! I wasted like ten minutes typing it out. It's the same thing DxO does.



Really? It doesn't sound like you did this:

[quote author=DxO Labs]
We perform noise measurement using a transmission target placed on top of a uniform light box. The transmission target, designed by DxO Labs, is made of a plate of thick black plastic with precision-drilled holes which are equipped with a range of neutral density filters designed to absorb the light identically for all wavelengths.

The filters are made of pure optical glass with no structures that can be measured as noise. (While other image quality measurement solutions make use of printed targets, we believe such targets are inappropriate for noise measurement testing, as the intrinsic noise pattern of the print paper may be recorded by the tested camera and then confused with the camera’s own noise pattern.)

We place high-density filters on neighboring positions to limit reciprocal illumination of the patches.
The light box (placed behind the target) is composed of two fluorescent daylight spectrum tubes with a diffusing sheet on top, achieving a perfect uniformity on each filter. The luminance is about 1500cd/m2.

We use filters having different light absorption levels ranging from 0% to 99.99% in order to test across a dynamic range of 4 density steps (= 13.3 f-stops — a dynamic range much greater than today’s digital cameras). When shooting such a chart, the sensor of the camera being tested sees a wide range of light levels, with a 1/10,000 ratio from minimum to maximum. For comparison, a printed target dynamic is typically 2 density steps (6.65 f-stops), which is inadequate to simulate high dynamic range or back-lit scenes.

Each uniform zone on the chart (a “patch”) is measured for luminance (cd/m2) with a certified luminance-meter; then all the values are input into DxO Analyzer software.

Once we measure the target and calibrate the DxO Analyzer software, the selected camera shoots an image of the noise target at different ISO settings, and we measure the noise for each color channel of the target image (R, Gr, Gb, B). We compute the mean gray level and noise values for each patch and for all images shot at different ISO settings. We then interpolate these numerical values for all gray levels to calculate and plot signal-to-noise ratio (SNR) curves, from which DxO Analyzer extracts the SNR 18%, the dynamic range, and the tonal range.
[/quote]

Perhaps the 10 minutes you spent typing out your 'procedure' wasn't the only time you've wasted on this 'analysis'...


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## jrista (Mar 9, 2012)

meli said:


> Somehow i doubt you would be so sensitive about its methodology and findings if LetTheRightLensIn's thread title was "Zomg 5d3 has 14DR u guys!"
> 
> In my case i tend to believe him; his approach -with the amount of data we have so far- seems reasonable, his results fits other people tests, and since Canon itself hasnt bothered to announce something about low iso performance, tends to point in the direction LetTheRightLensIn is.



If he insisted his means of arriving at such a conclusion was "exactly the same as DXO's", yes, I'd have issue with it. Its not so much about what he is saying as much as it is about the fact that he is claiming his approach and results are just as good and trustworthy as an institution that has a demonstrated track record of using consistent, repeatable, verifiable techniques to produce valid results.

I'd figure most of the people on this forum _realistically_ expect about a 1 stop improvement in DR, but _hope_ for a full two stop improvement that would maximize the potential of a 14-bit sensor. Realistically, I think the 5D III will exhibit around a 1-stop improvement in DR once tested by DXO (12.7-13 stops). However...thats all just _expectation and hope_. If someone told me they had run some kind of test that used "masked off" dark pixels from a RAW file and was able to prove with as much accuracy as DXO that the 5D III achieved exactly 14.0 stops of DR...I'd be extremely skeptical. (Having an understanding of the CR2 format, sounds a bit sketchy to me as the masked pixels are intended to be used to set black level by RAW converters, and they are purposely fixed at around 1024, rather than around 0 (don't ask me why Canon does that...its just what they do)...I don't believe they are a valid basis to use for measurement of DR.) 

At BEST, I think Canon might be able to achieve the same as Sony, 13.86 stops of DR, which is within the margin of error for 3 electron read noise and quantization error in ADC with a 14-bit sensor. Assuming Canon has not actually moved to a column parallel on-die ADC system in their sensors like Sony did (since Sony currently holds all the patents for such technology), realistically I'd be doubtful that DR will improve much past 13 stops, let alone 13.8. Given Canon's track record with improvements to DR, they have consistently improved it with each successive camera in any one of their lines. Taking the 1D APS-H series as an example using DXO data, the II had 11.1 stops, the III had 11.7 stops, and the IV had 12 stops. Read noise for those cameras was 29.7, 22.3, 16.6 e-, respectively. Canon has shown a notable ability to improve their low ISO dynamic range with reductions in read noise, and they have made some significant claims about improved DR that could bite them in the ass if it turns out to be false, or worse, the 5D III exhibited worse DR than the 5D II. 

Realistically, I'd expect the 5D III to approach 13 stops of DR, especially if they reduce read noise to 7D levels (8.7 e-). If Canon has been able to reduce read noise to Sony Exmor levels of about 3 e-, I'd expect the 5D III to push 13.5 stops of DR or more. However its all just _educated expectation_...even if I thought I could get accurate measurements from .CR2 files from sample images on the net, I wouldn't make any bold claims about my measurements being accurate to any degree, and especially not as accurate as DXO. I have no idea what kind of lighting was used to illuminate any sample image I might get my hands on, whether the camera was a pre-production model or not, whether the exposure settings were set exactly correct to measure DR for the type and intensity of the bulb used to illuminate the scene. So far no sample image on the net that I've come across is really ideal for measuring DR with any degree of accuracy as there are no guarantees about the viability of the information contained within them.


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## neuroanatomist (Mar 9, 2012)

meli said:


> his approach -with the amount of data we have so far- seems reasonable...



It's basing a conclusion on a questionable analysis of a single image. It's like asking one person who they plan to vote for in the next presidential election, then predicting that candidate will be the next President, with the data gathered thus far (n=1), that seems reasonable, too.

Sweeping conclusions based on very limited data, combined with outright false statements ("It's the same thing DxO does"), adds up to a lack of credibility.


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## traveller (Mar 9, 2012)

Oh boy, it's started again! 

Guys, I appreciate that people have spent quite a bit of time trying to analyse this, but can we not just hold off on this whole debate for a month until DXO Mark publishes their report on the 5D MkIII's and D800's sensors? That way we won't have to argue over the validity of test images, method etc. 

This isn't meant as criticism of anyone, it's just that I don't think it's worth getting riled up at this early stage...


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## Tijn (Mar 9, 2012)

jrista said:


> Does your method involved the use of a specialized test device designed just for the purpose of testing DR, that is finely calibrated to produce consistent test images containing tonal swatches of exact known intensities, lit by a very specific kind of light bulb that is capable of emitting a very specific amount of light, with a very specific color balance, at a very specific intensity?


Look, you clearly want to introduce a research hardware setup into this story. You're indicating that his method, lacking all this, is therefore not good enough. What exactly about *his* method is _wrong_, if you will, and how is it he's getting consistent results with the RAW files he's been "fiddling" with? Consistent results that are in line with "specialized test device" measurements, even?



> Claiming that your results are as accurate as theirs comes with a certain responsibility, and I'm sorry...but you repeatedly claiming that your as accurate and reliable as DXO, well its actually rather sad at this point.


He actually doesn't claim to be reliable, and he hopes he's wrong. He's listed out his entire procedure. We can take it with as much of a grain of salt as we like, as _we have all the information_. We can see what he did, we can see what he did wrong and we can think of the limitations of his findings ourselves. All of that does not take away the fact that his method of measuring these RAW files comes up with consistent results of the DxO measurements. That means that the chance that his method is "valid" has increased. Consistency is a good thing in different approaches to a similar kind of measurement.



> As it stands, all we really have at this point is your personal word...but someones word only has meaning to those who have reason to trust it.


No. He's told you how to do it, and he told you what he found. If you don't trust the man, go do it yourself. It's totally reproducable, which he also noted himself by the way because 4 other bloggers on these things came up with the same results themselves.



> We all know what your opinion is


In this discussion between him and you, you're the only one whose level of discussion does not come above that of "opinion". He has no personal opinion, just a method and an interest in the matter. If he made an error, be so kind as to point out that error to him. You're the only _opinion_ here, and that opinion seems to be close to sticking your fingers in your ears and saying lalala I don't hear you; because you have faith in Specialized Test Devices© but not in people doing manual measurements in RAW files and getting the same results. If you don't understand the research methods, I can imagine you only really TRUST the people in white lab coats and the big bleepy complex-looking machines. But nobody's asking you to TRUST this research. You are however trying to discredit it _simply for not being a complex-machine lab coat_. Give this guy some credit, he's getting consistent results. You clearly don't understand it, so really, you might as well just not comment unless you have something to say that will help us evaluate this method of DR data gathering.


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## neuroanatomist (Mar 9, 2012)

Tijn said:


> ...something to say that will help us evaluate this method of DR data gathering.



Still not sure I'd call it data gathering. As for consistent results, the method guarantees them. As for results that match proper empirical tests, a broken analog clock is correct twice a day. But whatever. 

Here's a question: when 'measuring' the dark noise level in the 'side masked area', what is the probability that the numbers provided for the dark signal are meaningful? He reports average values of 1024 for the 5DII and 2048 for the 5DIII - exact 2n values. Personally, I find that suspicious, and it seems more likely that those values are not actual signal, but rathet result from the camera firmware setting those pixels, which are outside the image area, to an arbitrary value as it writes out the .CR2 file. In that case, both the absolute value of the dark signal and the noise of that signal are not valid for DR determination.


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## altenae (Mar 9, 2012)

Numbers , numbers, numbers. 
Go outside take pictures. 
If you are happy and your customer is happy, then who cares if the DR is 10 or 11. 

The same story everytime a new camera is about to release.


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## Tijn (Mar 9, 2012)

neuroanatomist said:


> It's basing a conclusion on a questionable analysis of a single image. It's like asking one person who they plan to vote for in the next presidential election, then predicting that candidate will be the next President, with the data gathered thus far (n=1), that seems reasonable, too.


Now that's just mean, considering the DR measurement to be a binary value of 1 or 0 in a comparison... At least give a fair example.

Frog population. It's said frogs are heavier on island B than they are on island A. Island A frogs weigh 100g, with a standard deviation of about 2.
Give a guy a frog from island B, have him measure a frog's weight for 15 minutes, and then take his weight measurement to be a representative weight for that type of frog on island B.
Frog weighs 98g. Hey, this frog is almost just as heavy! Therefore, it looks like frogs on Island B aren't heavier at all; perhaps even lighter.

And even with all that, I'm not really sure if his measurements isn't actually more reliable than that.

Perhaps a ruler length measurement would be more fair. A ruler is found in some unknown metrics, but with descernible equally-distanced lines on it. You measure the distance between 10 lines to be 3.22 inches. From this measurement you deduce that for the next ruler of that type you find, the distance will also be 3.22 inches when you measure 10 lines.

For this guy's measurement, he's measuring the darkest bit of a RAW file (masked sensor area) and the brightest bit of the file (blown-out highlight). My question would be: if his masked sensor area measurement is valid (and may be taken as "black") and if his highlight may be taken as valid as well; would there be any significant difference examining 20 images rather than 1? For a RAW file linked to a sensor, isn't "blown-out white" always the same value in the RAW? It's blown out _at some value_, right? Does that value change from picture to picture?


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## Tijn (Mar 9, 2012)

neuroanatomist said:


> Here's a question: when 'measuring' the dark noise level in the 'side masked area', what is the probability that the numbers provided for the dark signal are meaningful? He reports average values of 1024 for the 5DII and 2048 for the 5DIII - exact 2n values. Personally, I find that suspicious, and it seems more likely that those values are not actual signal, but rathet result from the camera firmware setting those pixels, which are outside the image area, to an arbitrary value as it writes out the .CR2 file. In that case, both the absolute value of the dark signal and the noise of that signal are not valid for DR determination.


Good point. Do you reckon the darkest meaningful parts of an image (blown-out black) would have a significantly lower value?
Also, *if*(?) you can take the blown-out highlights to be the same value every time (i.e. blown-out white for a specific sensor will always be the same value for any picture with that sensor in RAW files), is it not strange that he actually got the same DR number as DxO predicted (for the Mk2)?


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## MazV-L (Mar 9, 2012)

Most of this technical jargon is way above my head :

However, I do wonder how anyone can fairly test 2 cameras, one they have or have used, the other they've never laid their hands on or even know anyone who has for any length of time ???

It'd be interesting to hear all the various opinions of the people who will be using the 5Diii AFTER they've have it and have been using them for at least a month or so.


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## neuroanatomist (Mar 9, 2012)

Tijn said:


> For a RAW file linked to a sensor, isn't "blown-out white" always the same value in the RAW? It's blown out _at some value_, right? Does that value change from picture to picture?



Do we know it's 'blown out white'? You might have noticed that reds tend to blow out more easily than blues, and a blown out red/green will show up as blown white, but may still be below peak for blue, due to the spectral sensitivities of the Bayer mask. That's one reason DxO measures noise in separate color channels then averages them. But since this guy is testing 'the same way as DxO' maybe he's doing that, but just didn't waste another 5 minutes to include that in the description of his method.


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## Tijn (Mar 9, 2012)

neuroanatomist said:


> Do we know it's 'blown out white'? You might have noticed that reds tend to blow out more easily than blues, and a blown out red/green will show up as blown white, but may still be below peak for blue, due to the spectral sensitivities of the Bayer mask. That's one reason DxO measures noise in separate color channels then averages them. But since this guy is testing 'the same way as DxO' maybe he's doing that, but just didn't waste another 5 minutes to include that in the description of his method.


Good, so there's also the possibility that his blown out white area wasn't blown out on all channels. I think that's a good reason to take his results with a big grain of salt. And hope they are indeed wrong. 

Still I think you should give him a bit of credit for trying, he's not a 'bad guy' at all. With the concerns you've just expressed about the black measurement and the blown-out whites measurements, this whole discussion (flame war..?) could have been quite a bit shorter and there wouldn't be so much ad personam pollution. No need for yelling at one another, they're valid concerns. It's something completely different from someone yelling "your machine doesn't have dials, therefore your method must be faulty". Still interesting he got the same values with the 5Dmk2, however. Perhaps he had better raw files for those.


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## neuroanatomist (Mar 9, 2012)

Tijn said:


> Good point. Do you reckon the darkest meaningful parts of an image (blown-out black) would have a significantly lower value?
> 
> Also, *if*(?) you can take the blown-out highlights to be the same value every time (i.e. blown-out white for a specific sensor will always be the same value for any picture with that sensor in RAW files), is it not strange that he actually got the same DR number as DxO predicted (for the Mk2)?



The dark signal may or may not be lower, but more importantly, the noise may be different, and that's the denominator in the equation (in fact, I'm not sure why he's subtracting the dark signal from the max first - the standard calculation is full well capacity over read noise, which translates to log2 (average peak / dark std dev). 

Semantics, but I wouldn't say DxO 'predicted' DR for the 5DII - they _measured_ it. What this guy is doing is trying to predict it, and I'll take a proper measurement over a prediction any day. I'm not saying he's definitely wrong, just that there's not enough data to go on. If he downloads the IR RAW files for 10 more cameras, does the same test, and comes out spot on with DxO's measurements for them, that would be convincing.


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## yunusoglu (Mar 9, 2012)

All aside, would any of you really be surprised if 5D3 had same DR as 5D2?
I wouldn't...


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## Mark D5 TEAM II (Mar 9, 2012)

Came across this on the troll-infested forums of DPR (eewww!):

http://forums.dpreview.com/forums/read.asp?forum=1032&message=40826910

*Pathetic regurgitation of the band-of-brothers mantra*
Posted by David Franklin
Date/Time 5:59:42 PM, Tuesday, March 06, 2012 (GMT)




> Look, I am not a defender or "fan" of Canon in general, and certainly not of the 5DIII, which I have never even held, much less shot and tested. But I am a working pro who shoots mostly at base or low ISO, sometimes of very technically difficult subjects with difficult lighting and lots of PP. I have never, ever, in tens of thousands of exposures using a 1DsIII (supposedly very close in quality to the 5DII), had a single issue with "banding." I'm not saying that banding is impossible to show after torturing a file to an extent that is beyond the realm of reasonably expected real-life use, perhaps from shooting a very difficult image very, very badly, with no planning or execution of alternate exposures to fall back on. But, in the history of photography, this has been called failure on the part of the photographer, rather than an issue with which to pillory a camera (or sensor, or film) company. Showing banding is apparently a very nice tech hobby for some, but not a terribly important issue in cases of even decent, much less good, photography.
> 
> And, by the way, just for the heck of it, I decided to do a small experiment. Because I don't have access to any raw file or truly perfected raw converter for a Canon 5DIII, I decided to look at that paragon of sensor goodness, the Nikon 800. I picked, pretty much at random, the only D800 file I had on my hard drive, the low ISO "Library" sample, an otherwise very amazing image for its great detail with very limited deep shadows, making it not the best image example to look for banding faults. When I merely applied the 100% shadow lift in PSCS5, and looked at the deepest shadow areas (very very small areas in an image that is otherwise very evenly lit for mid and low tones), and examined it at 200-300%, voila, what appears to me to be cross-hatched shadow banding appears.
> 
> ...


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## KeithR (Mar 9, 2012)

neuroanatomist said:


> It's basing a conclusion on a questionable analysis of a single image.



On that...

Something that's creasing me up about yer man's assertions is that I've been able to torture-test _umpteen_ D7000/K-5 files into banding of a sort practically indistinguishable from that the pixel-peepers on DPR have dragged out of the 5D Mk III file - so what does that prove about the Sony sensor?

_Nothing_, Real World.

I've also been able to drag 7D files up by four or five stops without _any_ problems with the banding that some "experts" insist is guaranteed from that camera in such circumstances, and I'll bet a large lump of cash that I'll be able to do likewise with 5D Mk III files.

It's actually a really easy issue to deal with if you simply use the right converter - for example, have you seen how much clean detail Lr 4 can bring out with the Shadows slider? I was playing last night with some 7D files (shrubs in bright light with black shadows, as it happens), and could render the shadow areas almost "daylight" with no banding penalty.

DPP and - of all things - Photodirector, are also _excellent_ in how they deal with shadows without banding.

And who on Earth _needs_ (emphasis intentional) that many stops of shadow recovery anyway?


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## awinphoto (Mar 9, 2012)

It's only 4:30 in the morning here so dont jump all over me, but in terms of a digital image, just thinking logically, there's a very finite white and a very finite black. In terms of photoshop for instance, black is 0, white is 255. You cannot extend that number range any more than that. Given that a stop, in essence is 100% more light than the prior stop, I suppose camera manufacturers can in essense desensitize files... make the white detail even more subtle, making shadows even more subtle giving the illusion of more DR, more stops, but A) there's no getting around digital files limits, and B) there will be even less information in each stop range, am I right?


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## 3kramd5 (Mar 9, 2012)

LetTheRightLensIn said:


> 3kramd5 said:
> 
> 
> > So... what are you doing? Blowing the highlights and measuring, blowing the shadows and measuring, and computing the magnitude between them? If you repeat the same calcs for every 5D3 sample do you get the same thing? If you repeat for every 5D2 image do you get the same 11.2? Or are you just measuring the DR of a single image?
> ...



Setting aside the log function to represent it in stops, I'm just trying to understand the calculation.

Correct me if I'm wrong: masked area = some part of the sensor that is physically blocked from light but still records brightness values. By definition, this would be the darkest part of any exposure.

So when you say you're measuring noise, are you reading random values from that black area (which in theory should be 0) and determining the minimum level at which noise no longer occurs?

Then a similar procedure is done in a blown out area?

Then the magnitude between dark and light is DR?


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## neuroanatomist (Mar 9, 2012)

3kramd5 said:


> Correct me if I'm wrong: masked area = some part of the sensor that is physically blocked from light but still records brightness values. By definition, this would be the darkest part of any exposure.



Allow me to correct you.  Although the OP certainly implies that is the case, the 'masked area' the OP is referring to is not physically blocked from light - lenses project an image circle, and for an EF lens, a FF sensor is the largest 3:2 rectangle than can be inscribed within that circle, such as the red box below:







So, what he's calling the 'side masking area' - the regions to the left and right of the red box - are actually being illuminated by light from the lens. Why, then, are those regions 'black' in the RAW file? Because those regions of the sensor are _electronically_ turned off (technically, set to an arbitrary value). Given that, I remain unconvinced that the method described by the OP is valid.


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## unfocused (Mar 9, 2012)

Perhaps someone would be kind enough to take a stab at this http://www.canonrumors.com/forum/index.php/topic,4154.msg85614.html#msg85614 to help us non-techies understand if we should care about this discussion.


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## 3kramd5 (Mar 9, 2012)

neuroanatomist said:


> 3kramd5 said:
> 
> 
> > Correct me if I'm wrong: masked area = some part of the sensor that is physically blocked from light but still records brightness values. By definition, this would be the darkest part of any exposure.
> ...



Those regions are being illuminated, but what's there to record those values beyond the area of the sensor?

Does the sensor physically extend beyond the 36x24 area and they disable the band of pixels outside the perimeter? I guess that makes sense from a design standpoint (to ensure you get the full desired frame, you cut sensor a little larger and hold back the outliers).

I'd never really given a lot of thought to sensor design before. Thanks for bearing with me.


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## meli (Mar 9, 2012)

altenae said:


> We are all spending hours and hours on numbers.
> Very sad. Very sad.
> 
> Some time ago I saw an image taken from a MF and I was blown away.
> ...





altenae said:


> Numbers , numbers, numbers.
> Go outside take pictures.
> If you are happy and your customer is happy, then who cares if the DR is 10 or 11.
> 
> The same story everytime a new camera is about to release.



Guys i agree with both of you, its all about the image. 

Now lets get it straight. 
This is Canonrumors forum. Its a specific Brand product discussion point. Its not about the trade its about the tool. 
If i want to talk about photography i'll go and discuss it in a photography forum. If i want to talk about the tools, then here is the right place.


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## neuroanatomist (Mar 9, 2012)

3kramd5 said:


> Those regions are being illuminated, but what's there to record those values beyond the area of the sensor?
> 
> Does the sensor physically extend beyond the 36x24 area and they disable the band of pixels outside the perimeter? I guess that makes sense from a design standpoint (to ensure you get the full desired frame, you cut sensor a little larger and hold back the outliers).



No, technically the sensor is physically 36x24mm (well, approximately 36x24 as Canon states), but not all of that is active space - the edges aren't used. So, the 5DIII is '22 MP' but if you look at the detailed specs, it's actually specified as 22.3 million 'effective pixels' but 23.4 million 'total pixels'. It's those extra 1.1 million pixels (the non-effective ones) that the OP is sampling from in the 'side masking area'. The point is, though, that they are pixels which are being illuminated, but not read out in the RAW file - so, I don't see how it's valid to assume those pixels are representative of image pixels exposed to no light.


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## 3kramd5 (Mar 9, 2012)

neuroanatomist said:


> No, technically the sensor is physically 36x24mm (well, approximately 36x24 as Canon states), but not all of that is active space - the edges aren't used. So, the 5DIII is '22 MP' but if you look at the detailed specs, it's actually specified as 22.3 million 'effective pixels' but 23.4 million 'total pixels'. It's those extra 1.1 million pixels (the non-effective ones) that the OP is sampling from in the 'side masking area'. The point is, though, that they are pixels which are being illuminated, but not read out in the RAW file - so, I don't see how it's valid to assume those pixels are representative of image pixels exposed to no light.



Well, for whatever reason, if they do indeed merely use software to black out border pixels that have been exposed, then it seems that they have little bearing actual DR. As they say in engineering analysis, garbage in = garbage out.

Maybe there is a correlation between actual exposed black and what value Canon chooses to apply to those pixels, however, in which case the method may translate to actual DR.

iunno.


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## Daniel Flather (Mar 9, 2012)

LetTheRightLensIn said:


> (and if you look at all the Canon press they kept talking about it being better.... at mid and high isos. I was hoping they just forget to mention improved low iso, but i guess they didn't mention it because they didn't do much there this time. at least the high iso stuff should be better though.)



Just shoot at higher a iso, moar DR, problem solved. There's more than one way to starch your nose.

TIMTOWTDI


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## jrista (Mar 9, 2012)

neuroanatomist said:


> No, technically the sensor is physically 36x24mm (well, approximately 36x24 as Canon states), but not all of that is active space - the edges aren't used. So, the 5DIII is '22 MP' but if you look at the detailed specs, it's actually specified as 22.3 million 'effective pixels' but 23.4 million 'total pixels'. It's those extra 1.1 million pixels (the non-effective ones) that the OP is sampling from in the 'side masking area'. The point is, though, that they are pixels which are being illuminated, but not read out in the RAW file - so, I don't see how it's valid to assume those pixels are representative of image pixels exposed to no light.



This is exactly correct. All canon sensors have two areas of "black masked pixels" to the left and right edges of the sensor. Based on the CR2 format, there are three columns of pixels on each side. There have been many reports that the base value of these pixels is fixed at 1024 +/- some deviation of 3 +/- 2 to 3 units (0 to 6 units). So you might see values here between 1018 to 1030. The deviation around 1024 may be due to read noise, can't say for sure. Either way...using the masked pixels to determine black level will most likely not produce valid results. (Why Canon does this or exactly how these masked pixels are intended to be used is not entirely known, the general assumption is that they are for calibration purposes. If one were willing to dig into Canon's public RAW processing algorithms, the reason could probably be determined...I have not done so myself, and none of the resources I've found have any definitive information about exactly how these masked pixels are used.)


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## Daniel Flather (Mar 9, 2012)

neuroanatomist said:


> 3kramd5 said:
> 
> 
> > Correct me if I'm wrong: masked area = some part of the sensor that is physically blocked from light but still records brightness values. By definition, this would be the darkest part of any exposure.
> ...



Ok, but the sensor is 24*36mm, so whatever light hits the sensor is your image. The sensor is not round. Again, correct me if I'm wrong.


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## Daniel Flather (Mar 9, 2012)

jrista ^^^ answered my Q, thanks.


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## neuroanatomist (Mar 9, 2012)

Daniel Flather said:


> Ok, but the sensor is 24*36mm, so whatever light hits the sensor is your image. The sensor is not round. Again, correct me if I'm wrong.



Nope. As jrista just confirmed, there are intentional 'dead/inactive' pixels at the edges of the sensor, which is why the specs for every Canon dSLR list a certain number of millions of total pixels, and a somewhat smaller value for 'effective pixels' - usually 3.5-5.5% less than the total pixels on the sensor. The number that is advertised for the camera (e.g. 18 MP for the 7D, 21 MP for the 5DII) are the effective pixels (those cameras have 19 MP and 22 MP total pixels, respectively).


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## Daniel Flather (Mar 9, 2012)

Thanks neuroanatomist.


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## Orion (Mar 9, 2012)

I LOVE CANON!

I LOVE PHOTOGRAPHY!

how's that for dynamic range!?

Go out and enjoy your camera . . . whether you are a Nikonian or Canonite! Both make wonderful cameras, and it is a waste of time (with all due respect) to 'worry' about what I consider trivial things. In the end, if trivial is the game, then many Pulitzer Prize winning photographs have no place in this thread or any other. . . .

LONG LIVE ART in purest form.


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## KeithR (Mar 9, 2012)

jrista said:


> All canon sensors have two areas of "black masked pixels" to the left and right edges of the sensor.



Some converters seem to be able to get past the masking, too - 7D conversions in (say) Lightroom are 5184 x 3456, but Raw Therapee conversions of the same files are 5194 x 3457.


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## LetTheRightLensIn (Mar 9, 2012)

jrista said:


> Does your method involved the use of a specialized test device designed just for the purpose of testing DR, that is finely calibrated to produce consistent test images containing tonal swatches of exact known intensities, lit by a very specific kind of light bulb that is capable of emitting a very specific amount of light, with a very specific color balance, at a very specific intensity? Do you take dozens of sample shots of said test device, evaluate each individual shot to produce very accurate measurements into a data sample set? Do you aggregate the measurements of that data sample set to produce a scientifically accurate mean, standard deviation, ratios, etc.? Do you have your results verified by multiple parties for accuracy? Is your final conclusion based on those verified results? Are all of your test cases for every brand of equipment you test subjected to the EXACT SAME TEST, done in the EXACT SAME WAY, to minimize deviation between the results of various brands, models, and even samples of specific equipment? Do you have a reputation as someone who does these things...a track record of verifiable accuracy?
> 
> DXO doesn't just take a sample image and perform some little procedure on it to come up with the dynamic range numbers they publish. Claiming that your results are as accurate as theirs comes with a certain responsibility, and I'm sorry...but you repeatedly claiming that your as accurate and reliable as DXO, well its actually rather sad at this point. As it stands, all we really have at this point is your personal word...but someones word only has meaning to those who have reason to trust it.



Wow, did you even read the procedure? Do you even know how DxO measures lowest ISO DR?? How about reading that stuff first before spouting nonsense. It has nothing to do with wedged and special light bulbs and so on. Trying to find out what gain they use for a given ISO or the SNR is trickier but I am not doing that. I, and the others, are simply measuring ISO DR!

And as for millions of samples, obviously not, but all the same, as I said, just using one black frame from my 5D2 and I ended up actually getting THE EXACT SAME numbers for 5D2 ISO 100 DR as DxO did TO THE TENTH OF A STOP (the error bars are probably a bit larger than a tenth of a stop anyway, but by chance, it ended up being exactly the same).

Have you read anything I or any of the others have said?

If you think all half dozen of us are lying as some sort of dirty paranoid conspiracy against you then you have the files, you have the procedure, you have the software to do it, go do it yourself and see what you come up with.




> You've done some "fiddling", and you have your personal conclusions. As far as I can tell, this supposed "engineer" your a fan of has also done some "fiddling", and also has his own personal conclusions. Speculation and hearsay, but personal conclusions nevertheless. You've been repeating your conclusions all over this forum for a few days now. Its certainly your prerogative to continue, but personally, I would stop comparing my own little home-grown, ad-hoc DR evaluation method to the precision testing performed by DXO...save yourself a little face.



It is not ad hoc. It's the same procedure people used on all of the past cameras. Heck the same procedure was used when he used to post in Canon forums, and is probably on his website, of one of the four physicists who came up with Heterotic String theory which helped launch the first super-string revolution. Granted everyone can make mistakes and come up with incorrect procedures and make mistakes, but I haven't see anyone discredit this method and the results it gives seem to match what DxO gets (who BTW are not perfect anyway, their optical tests have some bizarre results: 16-35 2.8 has sharper corners at f/2.8 than at f/5.6; at 200mm f/2.8 they say the 70-200 2.8 IS is sharper than 2.8 non-IS is sharper than 2.8 IS II; 70-300 non-L is sharper than the L at 300mm wide open, etc.) and as far as it seems it sounds like DxO is using the exact same procedure (although at higher ISO they plot the points at effective ISO and they do a series of measurements to come up with that, but that is irrelevant here).


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## neuroanatomist (Mar 9, 2012)

Ok, let's go back to the beginning.



LetTheRightLensIn said:


> Assuming the side masking area can be used for the measurement then:



I contend that the above assumption is invalid, and it's the assumption on which the conclusion is based. Do you have data to support the assumption that the side masking area's signal value and standard deviation are representative of the portions of the sensor that are actually used to record the image? I've got an open mind about this, but I must confess, I get _really_ suspicious when someone 'measures' numbers in a system where a log2 scale is commonly used, and the resulting values are exact integer results of 2n. 

EDIT: You've got a 5DII, right? So, can you shoot a black frame (lens cap on) and compare the ISIS data from the masked edge with the center of the frame?


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## LetTheRightLensIn (Mar 9, 2012)

altenae said:


> We are all spending hours and hours on numbers.
> Very sad. Very sad.
> 
> Some time ago I saw an image taken from a MF and I was blown away.
> ...



Just for the record some of the pixel-peepers in the forums actual do go out and shoot too. It's not an either or question. 

And sure you can take amazing shots with this or that, no question at all so you don't need this or that other thing. But there may be types of amazing shots you can't take with cam at all or not with a high take rate that you might on a different one.


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## LetTheRightLensIn (Mar 9, 2012)

neuroanatomist said:


> LetTheRightLensIn said:
> 
> 
> > I listed my entire procedure in detail! I wasted like ten minutes typing it out. It's the same thing DxO does.
> ...



Perhaps the 10 minutes you spent typing out your 'procedure' wasn't the only time you've wasted on this 'analysis'...
[/quote]

As I said I was not measuring SNR, not measuring integrated tonal response, not measuring color fidelity, not measuring for actual ISO ratings, etc. They are measuring tons more stuff, lots of more complicated stuff. I was just measuring maximum DR at base ISO which is vastly simpler than doing all of that other stuff. It is possible that their software extracts the dark current patch SNR ration and the blown channel and does actually what I and others have done. And I mean I did end up with the exact same ISO 100 results for the 5D2 DR.

I just hope that the main sensor area turns out to not act like the masked area this time. That would be awesome. I'd love to be wrong. But also note that all of the talk from Canon about the 5D3 has carefully left out low iso, they always mention improved for mid and high iso. 

And while this next post below is a bit speculative, his info is a bit down the line and speculative but how about this quote from someone not from Canon but with ties to them (I don't know who he is but he has been right about everything Canon the last few years on larger scale issues, he certainly might not have all the itty bitty tech stuff correct, etc.), quoting his post on another forum:

"I told you so, the 5DmkIII sensor is mainly a "polished" version of the former mkII sensor. Not that this is not a real improvement, but the step forward in real image quality is in fact marginal if you shoot RAW mainly. The 1Dx however has a sensor with a complete redesign. Expect it to have some real native characteristics that are above the 5DmkIII. .... The 1Dx performs some better in almost every department..... ISO, DR.... except for a few mp. Still the 5DmkIII..... is mature enough to completely satisfy the needs of enthusiast amateurs, semi pro's and professionals who prefer the compact body size over the 1Dx's additional qualities."

Off case take that with a grain of salt, but it sounds like, as some on DPR speculated, that maybe (again this is very much speculation now and may be prove to be entirely wrong) they may have decided to use the old fab for the 5D3 to save money again and only used the new fab for the 1DX sensor.

And I think he may be playing down the high iso improvements of the 5D3 a little bit. And maybe the 1DX sensor won't even be that different and it was just marketing spiel. 

Anyway this guy has hardly been a Canon basher, in fact, he had long been a very 100% rah-rah cheerleader on everything they ever did.


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## LetTheRightLensIn (Mar 9, 2012)

jrista said:


> (Having an understanding of the CR2 format, sounds a bit sketchy to me as the masked pixels are intended to be used to set black level by RAW converters, and they are purposely fixed at around 1024, rather than around 0 (don't ask me why Canon does that...its just what they do)...I don't believe they are a valid basis to use for measurement of DR.)



I hope that will turn out to be the case this time, that the masking area is not a valid basis this time, and that all my measurements will not match what happens when you measure the main sensor area. But it has proven to be a valid basis for use in the past. I don't think it was tried for all off the different bodies, but it seemed to give identical or quite close results when it had been tried. I was initially a little skeptical of it myself but the results were same ballpark completely.

But yes, might it be different this time? It is always possible. Judging by the past it is probably grasping at straws, but maybe this time. 

I'm starting to think if they did improve low ISO DR it might only be with the 1DX this time. I hope the 1DX at least has it improved since then we know 5D4 and so on will get it and that Canon is back on track. But it would be pretty annoying to 5D3 users, if they used the cheap old fab and yet still charged $500 more the Nikon (produced on a new fab) and saved the new fab for the 1DX only.




> Taking the 1D APS-H series as an example using DXO data, the II had 11.1 stops, the III had 11.7 stops, and the IV had 12 stops. Read noise for those cameras was 29.7, 22.3, 16.6 e-, respectively. Canon has shown a notable ability to improve their low ISO dynamic range with reductions in read noise, and they have made some significant claims about improved DR that could bite them in the ass if it turns out to be false, or worse, the 5D III exhibited worse DR than the 5D II.



OTOH they have yet to have any low ISO DR improvement since the 1Ds3. The 5D2 was no better nor was the 1D4.

I expected the 5D3 and 1DX to be a lot better, but it seems quite likely that the 1DX is the last hope now.



> I have no idea what kind of lighting was used to illuminate any sample image I might get my hands on, whether the camera was a pre-production model or not, whether the exposure settings were set exactly correct to measure DR for the type and intensity of the bulb used to illuminate the scene.



You don't use any lighting at all for a dark current reading. And for a blown channels max raw levels it doesn't matter the lighting either, if every channel is blown out it is blown out.

Again we are not talking trickier stuff like measuring middle tone SNR or what the ISOs really are or tonal response or CFA array response and so on, that stuff is trickier but note that I am not mentioning having measure that sort of stuff either. I even said I await the DxO results for that.


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## LetTheRightLensIn (Mar 9, 2012)

neuroanatomist said:


> Tijn said:
> 
> 
> > ...something to say that will help us evaluate this method of DR data gathering.
> ...



take black frame with you 5D2 and measure the blackpoint and it is right around 1024 in the center of the imaging area and in the masking area, above ISO1600 I started getting slightly higher values 1025 and then eventual up to 1034 by ISO 25,600. They were not all to the decimal point, but whether it is 1023.8 for 1024.1 for a patch doesn't matter.

You can find the black level of 1024 for the 5D2 (most canon cameras have used 1024 or 2048) listed on tons of different sites or ask one of the raw processing software guys in one of the forums what level he set his raw converter to use for the 5D2.

And it's not like this MY procedure anyway. Lots of people have used it and was hardly the first.


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## LetTheRightLensIn (Mar 9, 2012)

Tijn said:


> neuroanatomist said:
> 
> 
> > Here's a question: when 'measuring' the dark noise level in the 'side masked area', what is the probability that the numbers provided for the dark signal are meaningful? He reports average values of 1024 for the 5DII and 2048 for the 5DIII - exact 2n values. Personally, I find that suspicious, and it seems more likely that those values are not actual signal, but rathet result from the camera firmware setting those pixels, which are outside the image area, to an arbitrary value as it writes out the .CR2 file. In that case, both the absolute value of the dark signal and the noise of that signal are not valid for DR determination.
> ...



the backpoint has stayed about the same across all ISOs for canon cameras (sometimes rising a bit towards the upper end for whatever reason)

the max saturation value stored differs by ISO setting
for instance to list just a few I found on the 5D2 at ISO:
100 - 15760
125 - 15761
160 - 12810
800 - 15761
1000 - 15762
1250 - 12812
12800 - 16383

it tends to be the same for base iso and 1/3 up and then be lower for 2/3 up stops and for very high isos it can go to a uniform really high value like say 16383

the 50D had the same pattern

the 40D was a little different since base iso, +1/3, +2/3 all had a different storage


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## neuroanatomist (Mar 9, 2012)

LetTheRightLensIn said:


> You can find the black level of 1024 for the 5D2



Based on the calculation you indicated, the black level is not nearly as relevant as the noise... Is the noise the same in the center as the masked area?


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## jrista (Mar 9, 2012)

@LetTheRightLensIn: Perhaps we are not referring to the same sources of information and data. I can no longer tell, based on statements about _low ISO DR having not improved from 5D II to 1D IV_ (which as far as I can tell from DXO data, it did. 5D II screen DR 11.16, 1D IV screen DR 11.46; 5D II print DR 11.86, 1D IV print DR 11.95. Given how bad low ISO read noise has been on Canon sensors, its not surprising they have trouble getting more than 12 stops.) First off, having re-read your previous posts, no...you did not say you were measuring SNR. Given that you are solely measuring DR, I'll certainly grant that is a much simpler test. But thats never really been my complaint.

Regarding the 5D II, I believe you can get more accurate results, because you can actually get your hands on one and create your own test images. Regarding the 5D III, unless I've missed something (posts regarding this topic are spread across several threads now), the best we have to go with are sample photos posted to the net (the best of which seem to be from IR at this point.) We can't be sure one way or another whether the darkest pixel of an IR sample shot is actually indicative of cap-on dark current read noise. At best, we can make assumptions. It seems _you came to that same conclusion_, which is why you used the black masked pixels in the CR2 file as a basis for minimum read level. I am pretty sure I have some bookmarks at home (and if I get the chance here at work, I'll see if I can search for them sooner) that have useful details about what those pixels are, what data they contain, and how to interpret that data. To put it simply, those pixels are specialty cases either for setting black point and/or calibration, and cannot reliably be used as a basis for minimum signal (there are some statistics about deviation around the base 1024 value they tend to have that you might be able to use to deduce a true dark frame minimum signal level...but even so, any conclusions based on such a measurement would not be particularly reliable as I'm not sure anyone fully understands those pixels.) 

Given the lack of a sufficient set of test images, I don't think we (the internet community at large exploring DR, SNR, banding noise, etc.) can make enough conclusions to be concerned or relieved one way or another. I think doing so, and claiming that the tests and the results are as reliable as DXO's, is asking just a bit too much (and putting a certain responsibility on yourself that you probably don't want in the first place.) (Hence my rather rambling approach before to asking: Do you really believe you are being scientific in your measurements?) To put it more succinctly: Without known-good test images that we are certain contain patches of nothing but read noise in pixels other than the black masked pixel columns to the left and right of the sensor...we can't really come to reliable conclusions one way or another...*about the 5D Mark III*. Additionally, this is in contrast to conclusions about tests performed with the 5D Mark II, which we can be reasonably confident of given that we can actually get our hands on actual 5D II cameras in order to generate viable test images that contain the right data.

Apologies for being obscure before, I was not making my point clear. I'm not necessarily doubting the validity of your test method in its context (although I do think use of masked pixels is not reliable.) I'm doubting the validity of the _test samples_ themselves as a means to calculate DR. As soon as someone gets their hands on an actual production (vs. pre-production) 5D III and can actually generate a cap-on dark frame and a cap-off channels blown frame, I'll be far more willing to listen to the conclusions as "reliable" and "similar to DXO".


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## LetTheRightLensIn (Mar 9, 2012)

3kramd5 said:


> LetTheRightLensIn said:
> 
> 
> > 3kramd5 said:
> ...



measuring a block in the masked off area where no light hits and the avg value is the black point, ideally every single value be exactly say 1024 or 2048 but there is noise from the read out electronics so the values bounce above and below the black point, i record the std dev, the read noise in ADU.

For the blown out channels, i put a big box around IR's image where there were bright specular highlights and recorded the highest value reported for the selected block, it is possible that they are not really fully 100% blown out, but since more than one highlight had the exact same peak value it seems likely they were, even if one channel was still a bit under or something and heck let us just assign the max 14bit value that can even be recorded it doesn't even change the results much, instead of 11.1 you get 11.23, so bid deal .13 stop difference, 1/8th stop, meaningless in any practical sense and if you chose the max 5D2 value then difference is even less than that, maybe 1/16th of a stop to what I reported.

If there is something to be had it would be in the dark current. We can just hope that they are doing something very different with the masking area this time.


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## t.linn (Mar 9, 2012)

KeithR said:


> And who on Earth _needs_ (emphasis intentional) that many stops of shadow recovery anyway?



Folks can argue back and forth about the validity of the tests and the sample size of one. I get that. This sentiment I don't get. 

As a landscape shooter I routinely expose as far to the right as I can and still encounter images where I need to draw considerable detail out of the darkness. It isn't the least bit uncommon to encounter scenes where the dynamic range easily exceeds the capabilities of my 5D2's sensor. This is, after all, why many photogs embrace HDR. 

If Sony can figure out a way to reduce the need to rely on HDR by providing greater dynamic range within a single capture, I expect Canon to be just as competent. It's not like they don't have the resources to compete.


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## LetTheRightLensIn (Mar 9, 2012)

neuroanatomist said:


> Ok, let's go back to the beginning.
> 
> 
> 
> ...



The version of IRIS out now understands the 5D2 so I can't seem to let it show the masking area. It sort of reads in 7D files although only a really small chunk, it does reveal some of the masking area, on my 7D the black levels are the same masking or central area as expected, the read noise is slightly different but close, tested it at ISO100 and ISO6400, very roughly 5% difference. I believe people found similar for the 5D2. It was a few years back I forget the exact details.

If we took the best scenario from and decided that the read noise should be 5% better (although on my 7D at ISO100 it was actually 5% worse in the main sensor area) and that the max raw level should have actually been 16384 max 14bit value then we still only get 11.3 stops (versus 11.1 stops). 

Maybe the read noise in the masked area will vary by far, far more this time. I hope so. It seems more likely that it won't than it will though.


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## LetTheRightLensIn (Mar 9, 2012)

jrista said:


> @LetTheRightLensIn: Perhaps we are not referring to the same sources of information and data. I can no longer tell, based on statements about _low ISO DR having not improved from 5D II to 1D IV_ (which as far as I can tell from DXO data, it did. 5D II screen DR 11.16, 1D IV screen DR 11.46; 5D II print DR 11.86, 1D IV print DR 11.95.



Yes 11.95 > 11.86 but that could easily be within margin on camera to camera sample variation and even if the difference is .09 or even .2. Can anyone really tell the difference between a camera with .09 or .2 stops more DR? That's meaningless in the real world. And that was my point, no meaningful DR improvement at base ISO since the 1Ds3.

I hoped the 5D3 would change that. Unless the masking area works a lot differently this time (it is possible, which is we have been asking for people with 5D3 to provide full black frames, but so far nobody has provided them, but not too likely) then it seems the 1DX is the only hope. I hope it does since it would at least prove that Canon is capable of improving this. But it sure would suck if they left it out of the 5D3 after all of these years and then they charge $500 more than the D800 on top. On paper at least, they did knock the 5D3 out of the park, but if they did have the better DR tech, it kinda stinks to charge so much more and not use. Anyway that is all speculation.

I do await the DxO tests. Very curious to see, especially, how the SNR measurements turn out. People have had a go at it and it looks like 2/3rds stop better, not bad, but this is tricky to measure and could be well off so I really await DxO for that.





> To put it simply, those pixels are specialty cases either for setting black point and/or calibration, and cannot reliably be used as a basis for minimum signal (there are some statistics about deviation around the base 1024 value they tend to have that you might be able to use to deduce a true dark frame minimum signal level...but even so, any conclusions based on such a measurement would not be particularly reliable as I'm not sure anyone fully understands those pixels.)



True, but when they were used in the past on a few cameras the ended up giving results within a tenth of a stop or so, which is plenty close enough, it's within margin of camera to camera sample variation and way, way, way below what would matter to anyone using the cameras, but maybe something changed this time, although they appear to look about the same as on the 7D though so that seems unlikely, we will see.

I agree that a true black frame would be preferable but the masking area seemed work well enough a few times before.


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## LetTheRightLensIn (Mar 9, 2012)

t.linn said:


> KeithR said:
> 
> 
> > And who on Earth _needs_ (emphasis intentional) that many stops of shadow recovery anyway?
> ...



Exactly. I don't know why some people keep going on about just learn how to exposure properly. It has nothing to do with that. Of course people aren't making a big deal about it just to get around not learning how to take photos! 

It simply means that if your scene has more than about 10 stops of DR then it won't be able to be captured, you either have to live with blowing out bright parts or sending potentially important parts of the image to pure black. 

Sometimes a filter can help darken the sky, keep the bottom part bright, but sometimes the light and dark don't match any filter pattern. Sometimes multiple shot can help although if you don't have tripod with you meshing them sometimes results in a bit of loss but ok always bring a tripod but even then sometimes things are blowing or swirling or moving around too much.

(and if something went wrong and the exposure was messed up on some one of shot, that you won't be able to rescue it as well)

So people shoot stuff where it will almost never matter at all, and fine, the threads on it have no meaning for them, excellent. Some people do shoot stuff will it might matter, or would like to be able to too, on occasion or even semi-frequently, for them it may matter.

if you never wnat to shoot stuff like that or are happy just avoiding stuff that can't work then fine, nobody says you have to be upset about lack of DR. For quite a few people this thread may have zero bearing on them whatsoever and that is awesome, but don't snidely attack those for whom it might. And even for those who would like more it hardly means we will throw our cameras in the trash they are still awesome for all that they can do!

Anyway I've said all that can be said so until we get black frames I have nothing more to say here.

Maybe they feel they don't even need to compete since if they see it brought up and someone get +2 and -30 each time what do they think but hey why bother lets just keep milking our old production designs. How do you get their attention if any attempt get smit down or troll-called in every forum.

Also possible is that Sony has the digital column parallel ADC so heavily patented up that the problem may be intractable for everyone else  and that Canon has been trying their best and that the tech they reported turned down years ago was turned down for legit reasons and not a few bucks savings. It is possible it is not the tiniest bit their fault. But that is sort of an even worse answer. Maybe there are split reads or some other methods perhaps though? Maybe if they eventually swithc to some radically new sensor tech it will be a new game?


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## neuroanatomist (Mar 9, 2012)

LetTheRightLensIn said:


> measuring a block in the masked off area where no light hits



Can you provide some evidence that those areas are physically masked? Because I don't believe that's the case. Based on geometry, light from the lens covers the whole sensor. So unless Canon has covered those pixels with opaque material instead of microlenses, they are being hit by light. If so, the 'dark reading' you're getting from them is totally artificial, as is the noise (SD) measured there - and thus, any determination of DR based on those values is meaningless. 

I've raised this point a bunch of times, with no response. That suggests to me you 1) don't understand the point (very unlikely), 2) don't buy the argument (possible, but a rebuttal would have been appreciated), or 3) understand and accept the argument but have no logical response other than admitting a flawed methodology, so you're choosing to say nothing instead. Regardless, I'm done arguing the point. As discussed above by me and several others, this is a totally moot point until a production 5DIII is available for testing.


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## LetTheRightLensIn (Mar 9, 2012)

neuroanatomist said:


> LetTheRightLensIn said:
> 
> 
> > measuring a block in the masked off area where no light hits
> ...



They are good points and I worried about them too the first time I saw someone suggest using the masking area since we had nothing else to go on at the point when this came up with the prior round. But for the cameras tried it seems to work to within a degree that is good enough.

As for light leaking, I did wonder, but as I said on my 7D, the read noise tends to be slightly lower, like 5%, not higher as would be expected if light were leaking in. The sealing may be super tight or maybe they somehow don't have them actually reading from a live well or something. I really don't know.

And yes I'm outta here too. I've defended myself enough. It wastes too much time and I'm tired or arguing and if all people want to do is attack and throw accusations and with 30 smites for each applause why the heck should I ever bother posting about anything anyway, or at the least why bother going on and on in defense and offering explanations. If I do post more I will simply post and be done with it and not respond and everyone can say whatever they want after that .


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## te4o (Mar 10, 2012)

And yes I'm outta here too. I've defended myself enough. It wastes too much time and I'm tired or arguing and if all people want to do is attack and throw accusations and with 30 smites for each applause why the heck should I ever bother posting about anything anyway, or at the least why bother going on and on in defense and offering explanations. If I do post more I will simply post and be done with it and not respond and everyone can say whatever they want after that .
[/quote]

@LTRLI (too long to spell) I applauded you for your open mind and for the boldness you have to oppose so many fans. You explained in good detail what you found and your conclusions are logical. I understand them as a warning against too high expectations for the new sensor at low ISO. However, giving an opinion about this sensor without a single production camera available, without the proper final RAW software, and without using them both yourself makes this just an approximation and a topic of interest for further research. Nothing more. 
Good to learn about "masking area" though. I'd love to see your results from the lens-cap-black-frame-test.
Don't be disappointed by opposition, Nietzsche says "there are many disappointed good 'men' standing in the way of progress..."
To all the rest, I think people like LTRLI are helpful to increase our own personal DR .


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## sarangiman (Mar 10, 2012)

Heck I gave you all +1's! I think all the arguing back & forth is great, as there is a lot to learn/understand! As long as we're civil about it 

I have a # of questions, especially for LTRLI, neuroanatomist, & jrista:

(1) If Canon claims quantum efficiency is up due to better microlens design, and if initial tests show better ISO performance for the MkIII vs the MkII with RAW files (i.e. no influence of noise reduction, hopefully), then doesn't all that mean that SNR is *necessarily* higher? And doesn't higher SNR *necessarily* mean greater DR, for the same general sensor design (assuming nothing actually got *worse* btwn the MkIII & MkII)? Am I missing something here?

(2) Let's say those masked pixels really are sealed/blocked off from light OR are somehow turned off. However, let's say they're still being read by the electronics & so they can still be an indication of dark noise. Then, you use:

_Equation 1:_ DR = log(base 2) [highest signal/stdev]

But for that calculated DR to be indicative of the max possible DR of the scene being recorded -- doesn't that presuppose a linear relationship between incoming light & recorded signal in the RAW file? Do we know this to be true?

(3) Related to question (2)... Has anyone actually established that _Equation 1_ is a standard, accepted, measure of DR? DXO says "Dynamic range is defined as the ratio between the highest and lowest gray luminance a sensor *can capture*"... note it doesn't say "... a sensor *records*". Again, assuming a linear relationship between incoming light & signal recorded (which is *not* true, for example, for film) in the RAW file, I guess this'd be the same. But but from DXO's testing methodology description (http://www.dxomark.com/index.php/About/In-depth-measurements/DxOMark-testing-protocols/Noise-dynamic-range), I thought they were using actual light source/ND filter combinations to measure the SNR & DR.

(4) I must say I find it strange that in DXO's methodology in the link above, they state that they use a setup "in order to test across a dynamic range of 4 density steps (= 13.3 f-stops — a dynamic range much greater than today’s digital cameras)"... but then report that the Nikon D7000 has 13.9 stops of DR. Is this just an outdated description?

Thanks in advance!


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## sarangiman (Mar 10, 2012)

I went back to the book 'Image Sensors and Signal Processing for Digital Still Cameras' and it speaks of the 'optical black' (OB) pixels around the active pixels that are necessary to determine a proper black level. I'm assuming that, by whatever mechanism, they have no light gathering capability (b/c, as neuroanatomist mentioned, light from the lens can fall on those pixels).

So, if those OB pixels are used to determine the black level, they *may *also reflect the noise generated by the read event & subsequent electronics. It *is*, however, curious that they're around 1024 for the 5D II & 2048 for the 5D III. That's highly suspicious... I'd love to know what Canon is doing there. Isn't that # roughly what the black level is set to? If so, I don't think you'd want to be setting the black level to ~2048... seems to me that'd lower DR... unless the blackest pixel in the Active Pixel area really has a lowest level of 2048 (seems highly unlikely).

I have to go back to dcraw & see what it sets as default black level for my 5D II.

Still, my other problem with this methodology is that recorded signal in the RAW file does not necessarily reflect input signal until someone shows this relationship is completely linear... at least that's what I think.


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## Ricku (Mar 10, 2012)

I saw this chart in another thread, and it looks like the D800 is the new DR king for sure.


The 5D3 and D800 are pretty much comparable, but only at ISO800 and above.. Below ISO 800, the D800's DR is heading sky high, setting a new record.


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## torger (Mar 10, 2012)

Numbers are hard to interpret, there are so many factors that don't show in a number. No measurement so far I've seen take noise quality (pattern etc) into account, which has a huge impact on subjective DR.

Even if 5Dmk2 and 3 measure the same, if pattern noise is less than usable DR will be better.

High ISO measurements often miss out on quantum efficiency and can be misleading due to that.

A test that I would like to see is mk2 and mk3 shooting the exact same test scene perfectly ETTR, and then push a shadow area (preferably containing a color checker) 3 stops and show the crops side by side, resolution is almost the same so no sacling is required. I suspect/hope that the mk3 will fair much better in such a test than these measurements indicate.


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## DavidRiesenberg (Mar 10, 2012)

Ricku said:


> I saw this chart in another thread, and it looks like the D800 is the new DR king for sure.
> 
> 
> The 5D3 and D800 are pretty much comparable, but only at ISO800 and above.. Below ISO 800, the D800's DR is heading sky high, setting a new record.



If this chart is true and not a result of some miscalculation, that would indicate that the D800 applies some sort of artificial curve to balance the shadows and highlights. An aggressive HTP sort of thing.


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## sarangiman (Mar 10, 2012)

> High ISO measurements often miss out on quantum efficiency and can be misleading due to that.



Why is that (mechanistically)?



> A test that I would like to see is mk2 and mk3 shooting the exact same test scene perfectly ETTR, and then push a shadow area (preferably containing a color checker) 3 stops and show the crops side by side



Why can't you do that with the RAW files posted for both cameras on Imaging Resource_ right now_ yourself? There's a Color Checker in those shots.



> If this chart is true and not a result of some miscalculation, that would indicate that the D800 applies some sort of artificial curve to balance the shadows and highlights. An aggressive HTP sort of thing.



HTP purposefully underexposes the shots (physically), & then applies a non-linear curve. If the methodology used in generating that graph for the D800 is similar to the method LTRLI used, then any sort of non-linear manipulation done after the exposure would not change the resulting calculated DR (b/c the end points of any non-linear curve would likely still be the same as for the linear curve, since there's no reason to change the absolute values of saturation or black). So I don't think that explains it.


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## torger (Mar 10, 2012)

Waiting for raw support in my raw processor before I can do investigations myself.


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## KeithR (Mar 10, 2012)

t.linn said:


> This is, after all, why many photogs embrace HDR.



Exactly my point - you don't _need_ the camera to provide 6 stops of adjustment.

And I'll reiterate: how much you can get out of the shadows depends _massively_ on the choice of converter, and some people just aren't prepared to put the effort in to find the best converter for _all_ their needs. 

If you need deep shadow recovery without banding, use a converter that can do it. They exist. 

It's a damn' sight cheaper than jumping ship, and a damn' sight less stressful than the photographer wasting his life away waiting for Canon to produce the perfect camera.

Maybe I'm unusual in this, but I actually enjoy the challenge of finding solutions to problems: it's a far more productive way to use my time than endlessly complaining about this thing or that on internet forums.


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## KeithR (Mar 10, 2012)

Ricku said:


> The 5D3 and D800 are pretty much comparable, but only at ISO800 and above.. Below ISO 800, the D800's DR is heading sky high, setting a new record.



Bill Claff, whose site this is from, is a long-time _fervent_ Nikon guy; and these graphs are based on estimated values for both the D800 and the 5D Mk III.

Big pinch of salt in order here...


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## bvukich (Mar 10, 2012)

KeithR said:


> Ricku said:
> 
> 
> > The 5D3 and D800 are pretty much comparable, but only at ISO800 and above.. Below ISO 800, the D800's DR is heading sky high, setting a new record.
> ...



Why is everyone getting all worked up about some guy's *GUESS* about sensor performance?


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## 3kramd5 (Mar 10, 2012)

Question for those who may know.

Do these test (the OP's method, those in links or DXOlabs' stuff) include sensor level processing?

The Sony A580 and Nikon D7000 use the same sensor, yet the Nikon is evidently capable of an extra .6 stops of DR. I assume that's due to Nikon's Active D Lighting processing, but maybe it's due to generally better front-side optics.

Any ideas?

http://snapsort.com/compare/Nikon_D7000-vs-Sony_Alpha_DSLR-A580


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## nightbreath (Mar 10, 2012)

3kramd5 said:


> Question for those who may know.
> 
> Do these test (the OP's method, those in links or DXOlabs' stuff) include sensor level processing?
> 
> ...


It might be an improved algorithm in ADC or the optics. I never saw how DxO measures DR of a specific camera and I doubt they use the same lens for different brands.


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## Ricku (Mar 10, 2012)

KeithR said:


> If you need deep shadow recovery without banding, use a converter that can do it. They exist.
> 
> It's a damn' sight cheaper than jumping ship, and a damn' sight less stressful than the photographer wasting his life away waiting for Canon to produce the perfect camera.


Interesting.

Please name one. I'm using LR3 right now. Soon LR4, but if there is something better out there for cleaner shadow recovery, I'd like to know.


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## Stvx (Mar 10, 2012)

Wow.
Some guys here sound like Public relation/marketing/lawyers from Canon.

I am actually amazed that this thread is still going on 

I started a thread one week before the 5DMkIII was launched, about the sensor technology (was it a fine tuning of the existing MkII model or something completely new):

My thread was simply deleted by the "administrator" after 5 minutes...

You can't obviously be too critical with Canon products on a site supporting the brand. If you want a more critical approach i guess you need to go on some other sites. ;D


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## jrista (Mar 10, 2012)

Some small notes about Sony sensors that may affect the discussion. First, and importantly: They have a variety of hardware-level built-in noise reduction technology. Two key types, if I remember correctly, as well as a couple other features that improve their sensors. One to pretty much eliminate fixed pattern noise by accounting for differences in transistors at the hardware level. Another that uses an extra accumulator that measures dark current noise before computing the charge accumulated in the photodiode itself (CDS, or correlated double sampling). In addition to these explicit noise reduction technologies, Sony Exmor sensors also use column-parallel ADC. High frequency electronics have the potential to introduce more noise. Sony's CPADC, being hyperparallel, means each ADC has to do less work, and therefor does not need to operate as fast or on as many pixels as ADC's in Canon cameras. This also leads to lower noise. They use copper wiring which allows the CMOS to be thinner, along with a double layer of microlensing (which appear to be gapless) to direct more light into each well. Sony holds patents for all of these technologies, as well as for an approach to backlit sensor fabrication (which does not seem to be used in Exmor sensors, not sure why.)

For one, Canon does not seem to have patents on similar technology in most cases. They do offer some hardware-level noise reduction in line with Sony's CDS, or correlated double sampling, to eliminate dark current noise before reading the photodiode charge. Canon seems to use a different approach to fixed pattern noise however, whereby they set a non-zero pixel level floor, such as 1024 (or possibly in the case of the 5D III, 2048). This information seems to be derived from masked off pixel borders around the edge of the sensor, and can be used to adjust the black point of a CR2 RAW image at time of processing. The non-zero floor allows both positive _and negative_ adjustments to black level, depending on how much things like fixed pattern noise exhibit. However, at least based on information I've been able to find so far, this non-zero floor does not seem to "push" the maximum saturation value up at all. As far as I can tell, this leads to a fixed limitation on dynamic range since your eating into the maximum saturation level with a higher-than-zero black level...and may very well be the reason Canon sensors have been stuck below 12 stops of DR.

All that aside, Canon has made _explicit_ claims about _improving_ the dynamic range of their new sensors. From the Canon EU site (http://cpn.canon-europe.com/content/education/technical/inside_canon_eos_5d_mark_iii.do; see under Image Quality, Processing & Playback):



> Like the EOS-1D X’s sensor the full-frame CMOS sensor of the _EOS 5D Mark III_ offers increased light sensitivity, image noise reduction at higher ISO speeds, *and a wider dynamic range*.



The above is from a caption. They also provide the below information:



> CMOS sensors make use of microlenses to direct the light into each pixel well. Canon’s first full-frame sensor with a gap-less microlens design is found in the EOS-1D X and the sensor in the EOS 5D Mark III features the same technology for improved light gathering ability. Gap-less microlenses mean that no matter what angle the light arrives at the sensor from it is directed into a pixel well where it can be used most effectively. In essence it means that no light that gets to the sensor is wasted by not making it into a pixel.



Unless Canon truly does not have an issue getting caught in an outright lie (i.e. if their new sensors still don't achieve more DR than the 11.95 stops measured by DXO or 10.3 stops measured by DR), such a claim has to mean _something_ has been improved with 1D X and 5D III dynamic range. (Or at least, so one would hope...)


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## neuroanatomist (Mar 10, 2012)

Stvx said:


> I started a thread one week before the 5DMkIII was launched, about the sensor technology (was it a fine tuning of the existing MkII model or something completely new):
> 
> My thread was simply deleted by the "administrator" after 5 minutes...
> 
> You can't obviously be too critical with Canon products on a site supporting the brand. If you want a more critical approach i guess you need to go on some other sites.



No, you can be quite critical here, that's not the issue. What leads to threads being deleted is when they turn into a flame war instead of a civil discussion.

Also, there was a period a little before the 5DIII was announced when a bunch of people started threads of a very similar nature about the new model, and the mods went through and merged them into just a couple of threads to decrease clutter. If you look at those threads (some run to 20 pages) you can see that the post titles jump around a lot because many threads were merged into one main one. So, it's quite possible that your thread was not deleted, but simply 'disappeared' as a separate entity because it was merged with others.


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## t.linn (Mar 10, 2012)

KeithR said:


> t.linn said:
> 
> 
> > This is, after all, why many photogs embrace HDR.
> ...



I think it is good to keep this point in mind. The fact that there is a work around—and with the HDR feature on the new 5D3 perhaps a relatively easy one—means that with some degree of extra effort whatever DR one needs is available to 5D3 shooters. (To be clear, when I refer to the "HDR feature" I refer to the fact that the 5D3 may be able to effectively capture a group of appropriately bracketed RAW images with minimal effort.)



> And I'll reiterate: how much you can get out of the shadows depends _massively_ on the choice of converter, and some people just aren't prepared to put the effort in to find the best converter for _all_ their needs.
> 
> If you need deep shadow recovery without banding, use a converter that can do it. They exist.



The DR limits being calculated are irrespective of any RAW converter. So maybe there differences between RAW converters but lets be clear that the difference in performance between a Canon and Sony sensor is not about the RAW converter being used. It's a real, quantifiable difference.

Now this is not to say that one RAW converter won't handles shadows and banding better than another. However the choice of RAW converter is not simply about output; it's also about workflow. LR users have potentially invested thousands of hours creating a catalog to manage hundreds of thousands of images. Switching converters can be like switching camera systems. It's not something that can necessarily be done on a whim.



> It's a damn' sight cheaper than jumping ship, and a damn' sight less stressful than the photographer wasting his life away waiting for Canon to produce the perfect camera.
> 
> Maybe I'm unusual in this, but I actually enjoy the challenge of finding solutions to problems: it's a far more productive way to use my time than endlessly complaining about this thing or that on internet forums.



Like many others involved in this discussion, I've got a 5D3 on pre-order; I'm not wasting my life waiting for a perfect camera. ;D And I don't consider most of the posts in this thread as complaining. It is threads like this on forums like this that raise awareness of issues with other users and even sometimes with Canon. Case in point: If you shoot video at all, you know that hundreds of threads like this related to the crippled video functionality of the 5D2 at its introduction (no manual control; a single odd frame rate) helped push Canon to make the changes necessary to turn the 5D2 into a professionally useful tool for video.


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## LetTheRightLensIn (Mar 10, 2012)

Oh I really shouldn't bother posting anymore but this is reasonable talk so:



sarangiman said:


> Heck I gave you all +1's! I think all the arguing back & forth is great, as there is a lot to learn/understand! As long as we're civil about it
> 
> I have a # of questions, especially for LTRLI, neuroanatomist, & jrista:
> 
> (1) If Canon claims quantum efficiency is up due to better microlens design, and if initial tests show better ISO performance for the MkIII vs the MkII with RAW files (i.e. no influence of noise reduction, hopefully), then doesn't all that mean that SNR is *necessarily* higher? And doesn't higher SNR *necessarily* mean greater DR, for the same general sensor design (assuming nothing actually got *worse* btwn the MkIII & MkII)? Am I missing something here?



It means that SNR would be better up in the realm where photon noise dominated read noise. But it does relatively little, in comparison, for the performance in the deep shadows compared to the read noise. So it can be that they have the same SNR in the deepest shadows near black but that one has better SNR say at semi-dark gray and brighter.



> (2) Let's say those masked pixels really are sealed/blocked off from light OR are somehow turned off. However, let's say they're still being read by the electronics & so they can still be an indication of dark noise. Then, you use:
> 
> _Equation 1:_ DR = log(base 2) [highest signal/stdev]
> 
> But for that calculated DR to be indicative of the max possible DR of the scene being recorded -- doesn't that presuppose a linear relationship between incoming light & recorded signal in the RAW file? Do we know this to be true?



It does and as far as I have scene there is and it is.



> (3) Related to question (2)... Has anyone actually established that _Equation 1_ is a standard, accepted, measure of DR? DXO says "Dynamic range is defined as the ratio between the highest and lowest gray luminance a sensor *can capture*"... note it doesn't say "... a sensor *records*".



I think they say records and captures because the read electronics can mess up what the sensor itself captured. I believe it has been shown that the 1D4 sensor, for instance, actually captures close to 14 stops but then the readout loses a few stops and that is what gets recorded in the RAW file and it's only 11.5 stops instead of almost 14.



> (4) I must say I find it strange that in DXO's methodology in the link above, they state that they use a setup "in order to test across a dynamic range of 4 density steps (= 13.3 f-stops — a dynamic range much greater than today’s digital cameras)"... but then report that the Nikon D7000 has 13.9 stops of DR. Is this just an outdated description?



The 13.9 is only after they have normalized it to 8MPs. Although it is true that even the basic camera DR does come in 13.35 for the D7000 so I think that description of their setup may be out of date. Prior to the Exmor sensors it may have been valid (although maybe some of those old sigmas?).


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## LetTheRightLensIn (Mar 10, 2012)

sarangiman said:


> I went back to the book 'Image Sensors and Signal Processing for Digital Still Cameras' and it speaks of the 'optical black' (OB) pixels around the active pixels that are necessary to determine a proper black level. I'm assuming that, by whatever mechanism, they have no light gathering capability (b/c, as neuroanatomist mentioned, light from the lens can fall on those pixels).
> 
> So, if those OB pixels are used to determine the black level, they *may *also reflect the noise generated by the read event & subsequent electronics. It *is*, however, curious that they're around 1024 for the 5D II & 2048 for the 5D III. That's highly suspicious... I'd love to know what Canon is doing there. Isn't that # roughly what the black level is set to? If so, I don't think you'd want to be setting the black level to ~2048... seems to me that'd lower DR... unless the blackest pixel in the Active Pixel area really has a lowest level of 2048 (seems highly unlikely).
> 
> I have to go back to dcraw & see what it sets as default black level for my 5D II.



It's sort of arbitrary what they decided to use as the blackpoint in the RAW file and it probably makes sense to chose some power of 2 rather than say 1117 or 2003 or something.



> Still, my other problem with this methodology is that recorded signal in the RAW file does not necessarily reflect input signal until someone shows this relationship is completely linear... at least that's what I think.



RAW files are said to be stored in linear fashion.


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## LetTheRightLensIn (Mar 10, 2012)

torger said:


> Numbers are hard to interpret, there are so many factors that don't show in a number. No measurement so far I've seen take noise quality (pattern etc) into account, which has a huge impact on subjective DR.
> 
> Even if 5Dmk2 and 3 measure the same, if pattern noise is less than usable DR will be better.
> 
> ...



This is true and there are hints that at high iso the noise of the 5D3 looks nicer than the noise of the 5D2 so the usable improvement might be a little bit more than whatever the measured improvement in SNR turns out to be and for scenes having extensive areas that are very dark there is a chance the 5D3 might visually do noticeably better than the plain measure SNR difference suggests. We don't really have great samples to compare that yet though.

The same might be true at low ISO but it's too hard to tell from the tiny little masking area. Pulling IR shadows you still do seem some vertical streaking though. It's really hard to say what the difference will be. Maybe it won't help at all. Maybe you will get an extra 1/2 stop of usable dynamic range down there or something for many shots even if the measured value is almost the same.


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## LetTheRightLensIn (Mar 10, 2012)

DavidRiesenberg said:


> Ricku said:
> 
> 
> > I saw this chart in another thread, and it looks like the D800 is the new DR king for sure.
> ...



actually the linear plot for DR of that type is the expected if you had a perfect read from the sensor at a certain stage of the readout, so the D800 is not applying any sort of weird curves (nor is the Canon, it curves over, which is NOT the expected, but it is not because of weird tone curves either but because part of the read out noise stage that doesn't come into play much at high ISO is not so hot so it shows up a lot at low ISO and you get diminishing returns compared to what you'd expect looking at the high iso numbers as you go to near base ISO since you get worse read performance at lower ISOs)


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## LetTheRightLensIn (Mar 10, 2012)

KeithR said:


> Ricku said:
> 
> 
> > The 5D3 and D800 are pretty much comparable, but only at ISO800 and above.. Below ISO 800, the D800's DR is heading sky high, setting a new record.
> ...



And a bigger pinch of salt for the postings of a long time 100% rah-rah Canon no matter what poster such as yourself .

BTW his charts follow the same pattern of 5D2 vs the other Exmor sensors on DxO, etc. so his results don't seem all that shocking for the 5D3 and D800. But yes, as he says too, they are preliminary estimates. We can hope the final results will change. But if I had to, I'd place money against it. While there is no saying patterns can't break, it's a safer bet that things work as they have in the past rather than suddenly change.


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## qwerty (Mar 10, 2012)

3kramd5 said:


> Question for those who may know.
> 
> Do these test (the OP's method, those in links or DXOlabs' stuff) include sensor level processing?
> 
> ...




The A580 has a Pellicle mirror ( http://en.wikipedia.org/wiki/Pellicle_mirror ), so the sensor has less light to work with. That gives slightly lower performance at a given ISO. The Nikon has a standard mirror that flips out of the way before the shutter opens.

Edit: looks like I may have been confusing the 580 with another Sony camera. Nevermind me.


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## sarangiman (Mar 10, 2012)

> part of the read out noise stage that doesn't come into play much at high ISO is not so hot so it shows up a lot at low ISO and you get diminishing returns compared to what you'd expect looking at the high iso numbers as you go to near base ISO since you get worse read performance at lower ISOs



LTRLI: Does the amplification based on the ISO setting occur before charge read out (before noise injection due to read)?


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## DavidRiesenberg (Mar 10, 2012)

LetTheRightLensIn said:


> actually the linear plot for DR of that type is the expected if you had a perfect read from the sensor at a certain stage of the readout, so the D800 is not applying any sort of weird curves (nor is the Canon, it curves over, which is NOT the expected, but it is not because of weird tone curves either but because part of the read out noise stage that doesn't come into play much at high ISO is not so hot so it shows up a lot at low ISO and you get diminishing returns compared to what you'd expect looking at the high iso numbers as you go to near base ISO since you get worse read performance at lower ISOs)



As far as I remember, I never saw a sensor that exhibits a kink in the curve like the D800 one. It doesn't happen with the D7000 or the Phase One (wide DR examples) at DXO. That's why in my technical-limited-knowledge logic it seems to me that Nikon felt that below ISO 800 the noise is low enough to justify some post capture adjustments.


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## sarangiman (Mar 10, 2012)

> I think they say records and captures because the read electronics can mess up what the sensor itself captured. I believe it has been shown that the 1D4 sensor, for instance, actually captures close to 14 stops but then the readout loses a few stops and that is what gets recorded in the RAW file and it's only 11.5 stops instead of almost 14.



I'm not sure I'm explaining myself properly. My concern is that by just looking at the RAW file, are you really measuring the number of stops recorded *in the actual scene* that was being shot? Seems to me that to be able to do that you'd have to have a wide range of subjects with different luminosities (i.e. the multiple ND filter set up that DXO says it uses), *measure those luminosities using a reliable spot meter*, then look at the RAW data and see the range of luminosities for which the camera is able to:

[list type=decimal]
[*]Give a reasonable SNR for the darkest luminosity recorded
[*]Differentiate one luminosity vs. the next on the higher (brightest) end
[/list]

By just looking at the RAW file, with no actual scene information, the only way the test would be valid would be if there was a directly linear relationship between the scene luminosity & the luminosity recorded in the RAW. Which your statement about the 14 stops going to 11.5 itself seems to show isn't the case.


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## LetTheRightLensIn (Mar 10, 2012)

DavidRiesenberg said:


> LetTheRightLensIn said:
> 
> 
> > actually the linear plot for DR of that type is the expected if you had a perfect read from the sensor at a certain stage of the readout, so the D800 is not applying any sort of weird curves (nor is the Canon, it curves over, which is NOT the expected, but it is not because of weird tone curves either but because part of the read out noise stage that doesn't come into play much at high ISO is not so hot so it shows up a lot at low ISO and you get diminishing returns compared to what you'd expect looking at the high iso numbers as you go to near base ISO since you get worse read performance at lower ISOs)
> ...



Oh that kink, I was ignoring that, I thought you meant something else. I think the said that he made a small mistake with the ISO400 reading on the camera, that would explain some of it. Or maybe in how the ISO got rated, once you go above base ISO and compare things it's a little trickier because of that. I doubt it's anything in the camera itself.

The 7D does get a bit of a kink in the SNR charts because it has an unusual form of gain, as opposed to offset, vertical banding that can add a little to the SNR and it has more influence at a certain point along the ISO scale, I think.


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## LetTheRightLensIn (Mar 11, 2012)

sarangiman said:


> > I think they say records and captures because the read electronics can mess up what the sensor itself captured. I believe it has been shown that the 1D4 sensor, for instance, actually captures close to 14 stops but then the readout loses a few stops and that is what gets recorded in the RAW file and it's only 11.5 stops instead of almost 14.
> 
> 
> 
> ...



Unlike film, the digital sensors have linear capture from the scene.
The 14 to 11.5 is because read noise makes the bottom few stops meaningless mess of randomness.


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## sarangiman (Mar 11, 2012)

> It means that SNR would be better up in the realm where photon noise dominated read noise. But it does relatively little, in comparison, for the performance in the deep shadows compared to the read noise. So it can be that they have the same SNR in the deepest shadows near black but that one has better SNR say at semi-dark gray and brighter.



Ah, all you're saying is that the absolute difference in SNR will be less for low signals vs. high, as is clear in this simple linear plot here of the SNRs for QE 1 vs QE of 0.5, assuming a read noise of 6e-:







This always begged the question in my mind: if you increase QE dramatically for a sensor without increasing full well capacity, don't you run the risk of blowing out the sensor for any given f-ratio & exposure combination compared to an older sensor with lower QE & same full well capacity? I realize that the increased QE sensor would have a lower gain for any f-ratio/exposure combination, but blown out is blown out... this always confused me.

Thanks.


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## neuroanatomist (Mar 11, 2012)

sarangiman said:


> This always begged the question in my mind: if you increase QE dramatically for a sensor without increasing full well capacity, don't you run the risk of blowing out the sensor for any given f-ratio & exposure combination compared to an older sensor with lower QE & same full well capacity? I realize that the increased QE sensor would have a lower gain for any f-ratio/exposure combination, but blown out is blown out... this always confused me.



Sure. 'Full well capacity' is measured in electrons, after conversion from photons. If QE goes up, you get more electrons per photons input, and the well fills faster. It's probably not a practical problem, though, since in most normal shooting situations a lower gain (ISO) would solve the problem.


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## sarangiman (Mar 11, 2012)

neuroanatomist, or anyone: Though I asked this previously, I think it got lost in all the back-and-forth -- is 'gain' at the pixel-level applied during charge reading? I.e. does the ISO setting determine the 'conversion gain' (µV/e-)? Meaning, if you have a very low signal, is increasing this gain advantageous b/c it will help offset the read noise to be injected & b/c of the limited precision of reading?


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## sarangiman (Mar 11, 2012)

jrista:


> Do you mean "charge reading" or "conversion of charge to a digital unit"?



Not sure what happened to your post, but I'm answering anyway... I mean during 'charge reading'. If it's just during 'conversion of charge to digital unit', then LTRLI's statement "part of the read out noise stage that doesn't come into play much at high ISO is not so hot so it shows up a lot at low ISO and you get diminishing returns compared to what you'd expect looking at the high iso numbers as you go to near base ISO since *you get worse read performance at lower ISOs*" wouldn't make much sense (if I understood what he was trying to say correctly).

I may be totally wrong.

But I'm basing my notion from this comment in the chapter on CMOS Image Sensors in "Image Sensors & Signal Processing for Digital Still Cameras" (assuming these are active, not passive, pixel sensors): "The active pixel concept in which a photogenerated charge is amplified in a pixel and the amplified signal is read out has its roots in the phototransistor array image sensor. One advantage of the active pixel is its suppression of noise generated and/or injected in the signal readout path..." (pg. 145).

Then again, no idea if this 'amplification' is the one you can set by ISO... someone more knowledgeable will have to chime in.


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## jrista (Mar 11, 2012)

Not really sure what happened to my post either. ISO, at least with Canon cameras, is a pretty ugly beast when you really dig into it (its not really as simple as I stated before.) Its not handled the same way at all ISO settings, and there are big changes once you get to really high ISO settings. Its not really actually handled just at one point, it can be handled at multiple points along the read and processing pipeline. 

Generally speaking, a specific ISO setting is achieved via per-pixel amplifiers, the ADC, as well as post-ADC digital "gain", which is pretty much the same as adjusting exposure during post processing. In the case of pre-1DX/5DIII sensors, Canon also used a full-stop native/third-stop push\pull approach. Analog gain (which could be via amplifier or amplifier and ADC) ISO only affected full-stop ISO settings: 100, 200, 400, 800, 1600. Beyond ISO 1600, you start seeing both analog and digital gain. When it came to third-stop settings, full-stop ISO gain would be applied, followed by a 1/3rd stop push or pull exposure adjustment. ISO 125 would be ISO 100 with digital "gain" of +1/3rd stop applied. ISO 160 would be ISO 200 with digital "gain" of -1/3rd stop applied. Things get really complex when it comes to higher ISO settings. For example, ISO 5000 would be:

+4 stops "clean" analog gain (pixel amplifier, I believe...never found any specific details)
+1 stops "dirty" analog gain (modified ADC gain, I believe...never found any specific details)
-1/3 stops "nasty" digital "gain" (reduction of EV of post-ADC digital image)
+1 stops "pretend" "gain" (setting in metadata that tells RAW processor that more digital exposure increase is necessary)

So, the initial four stops of clean analog gain by the pixel amplifier would conform to what you've read in your book. Modern CMOS sensors usually include nose reduction circuitry to make sure that the direct pixel read is as clean as possible (usually CDS, or correlated double sampling, to limit dark current noise...used in both Canon and Sony sensors; sometimes additional measures are taken to minimize fixed pattern noise caused by deviations in the performance of each pixels transistors relative to each other, etc.), so that when the pixer amplifier jacks up ISO according to the camera setting, its jacking up an electron count read as close to the real photon conversion count as possible. That would only be the case with full-stop ISO settings up to ISO 1600 on a Canon sensor, however. 

No one can say yet how Canon's new sensors handle ISO settings. One of the things I personally really want to know is whether analog gain, either at the pixel or via ADC or something else, is done for every ISO setting. The whole push/pull third-stop approach is rather annoying, as it always chops off/shifts at lest 1/3rd stop DR at those ISO settings. It also causes a very funky progression of noise levels. Full-stop noise is "normal", push stop noise is "excessive" (often worse than full-stop ISO two to three settings higher), and pull stop noise is "clean". ISO settings beyond 1600 (which, in the 1D X and 5D III, might actually be ISO 6400 or ISO 12800 now) pretty much get a double-whammy, with two kinds of analog gain as well as two kinds of digital exposure amplification, usually leading to a large jump in noise levels that really eat away at fine detail. It does sound like the new 1D X and 5D III sensors have incorporated new per-pixel pre-amp hardware noise reduction. Not sure exactly what kind of noise it reduces...but given that there appears to be practically no fixed patter noise in 5D III sample images, and at worst minor vertical banding noise...I'd venture a guess that it eliminates fixed pattern noise.

*Clean analog gain* (which I believe is best achieved via per-pixel amplifiers after fixed-pattern and dark current noise are mitigated during photodiode read) is how all ISO settings should be achieved in my opinion. I believe that is indeed how Sony sensors work...at least up to ISO 1600 on current camera models (I think they also do additional ISO adjustment in the ADC at higher ISO's.)


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## KeithR (Mar 11, 2012)

dilbert said:


> As long as the methodology used is the same across all cameras then it is valid to compare cameras with.


Oh, I'm sure they'll be OK, but as I say, some caution is in order.

Must be honest though - I struggle to understand where Nikon/Sony can have got the thick end of two stops from.


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## LetTheRightLensIn (Mar 11, 2012)

gotta get back to the game and then eagles but quickly, based on someone's black frame posts here (another thread):
disappointing results at ISO 100:

banding:
horizontal banding appears to be entirely removed, this is good, and will help make ISO look better and get less badly clumped chroma noise and all but vertical banding appears to be zero improved and it shows up enough that I don't think you gain any usable amount of low ISO DR back compared to the 5D2

so for low ISO I'm not sure the removal of horizontal banding alone will really help usable DR any since the vertical sticks out to the eye just as much, maybe here on there on parts of the image it might help (it ay be enough to help high iso look better though and make a difference)

DR:
5D2: 15760,1024,6.1 AU,3.8 8MP normalized ADU, DR - 11.2 , DR8MP - 11.9

5D3: 15309 (maybe the channels were still not quite blown though?),2048, 6.6 ADU, 6.4 normalized to 5D2 6.4 and then to 8MP 3.96, DR- 11.0 DRto5D2 - 11.0 DR8MP - 11.7
and let us say WP should be 15760 instead then DR8MP - 11.8
and let us even say it should be max 14bit 16383 - 11.8

so I actually get fractionally worse DR than for the 5D2, but it's for all intents, the exact same, within copy to copy variation and well within any difference you'd be able to notice

Sad to say but even the DX D7000 handily beats the latest Canon FF for DR, and not by a little. The D800, at 100% view, full 50% MP advantage may beat it by 2 stops, maybe even 2.5 usable stops.

I did not expect this at all. :'(

I think we just have to accept that it will do nothing for the ISO 100-400 non-action shooters. It's basically a big step up in AF and possibly some degree better image quality at high ISO (hopefully enough to matter, it looks like it might be, but can't be sure yet) only. Not that those are minor things, but still, not sure how that makes it $500 more than the 6D800. I am now really, really surprised they decided to price it above the D800.


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## Abraxx (Mar 11, 2012)

Oh, what I feared, no real DR improvement. 
If further tests confirm this, I'm not going to buy the 5D Mark III, especially not at the extreme price point Canon has chosen here in Germany.
DR improvement was crucial for me. I'm really disappointed if this turns out to be true. :'(


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## sarangiman (Mar 11, 2012)

I forget who posted this .CR2 file (I think it was either here or on dpreview), so, sorry I'm missing credit for it, but, vertical banding is pretty poor. This is +100 Fill Light, ISO 100 (it's a crop, not full image):






That just looks like FPN that shoulda been removed in internal camera processing... 

That's really going to limit usability of shadows in high dynamic range landscapes (& yes, I do shoot w/ Singh-Ray filters... but sometimes it's either not practical b/c of you're, say, shooting a cityscape without a simple horizon, or when even those filters aren't enough... e.g. when shooting long telephoto where effects of grad ND filters are minimal or, say, when shooting w/ the moon in the frame).


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## sarangiman (Mar 12, 2012)

jrista:


> One of the things I personally really want to know is whether analog gain, either at the pixel or via ADC or something else, is done for every ISO setting. The whole push/pull third-stop approach is rather annoying, as it always chops off/shifts at lest 1/3rd stop DR at those ISO settings.



It's kind of stupid that on the 5D2 you can set ISO steps at 1-stop increments, thereby never selecting any of those intermediate ISOs, but Auto ISO will still use the intermediate ISOs. Seems to me like it'd be helpful if Auto ISO also considered your setting of ISO increments. Along this train of thought, I wish Canon/Nikon/etc. would allow us full access to the hardware to modify the firmware ourselves... kind of like writing apps on iOS... would open up a world of possibilities for photographers with special interests. But I doubt we'll ever see that happen.



> given that there appears to be practically no fixed patter noise in 5D III sample images, and at worst minor vertical banding noise...I'd venture a guess that it eliminates fixed pattern noise.



I don't know about that... please see my previous post. That particular model of the 5D III has *as bad or worse vertical banding* than my 5D II...


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## jrista (Mar 12, 2012)

sarangiman said:


> > given that there appears to be practically no fixed patter noise in 5D III sample images, and at worst minor vertical banding noise...I'd venture a guess that it eliminates fixed pattern noise.
> 
> 
> 
> I don't know about that... please see my previous post. That particular model of the 5D III has *as bad or worse vertical banding* than my 5D II...



There are slight differences in banding vs. fixed pattern...I believe they are caused by different gains at different parts of the pipeline. The fixed pattern stuff is finer and cross-hatched, and pretty much always the same in every frame. Whatever causes banding is different, and the banding can change frame to frame. As far as I can tell, the fine, FIXED PATTERN noise is gone in the 5D III. There does appear to be some vertical banding, however I've seen inconsistent results. Some samples seem to exhibit it, while others don't seem to exhibit any at all. I have been curious if that was due to differences in pre-production samples or something like that? Anyway, I think banding and fixed pattern noise are separate types, caused by effectively the same thing, just at different parts in the read pipeline...and banding does not exhibit the same in every frame where as fixed-pattern (by definition) would.


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## Abraxx (Mar 12, 2012)

Abraxx said:


> Oh, what I feared, no real DR improvement.
> If further tests confirm this, I'm not going to buy the 5D Mark III, especially not at the extreme price point Canon has chosen here in Germany.
> DR improvement was crucial for me. I'm really disappointed if this turns out to be true. :'(


I had a chance to touch the new 5D & the D800.
I have to slightly adjust my statement above, I still have an issue with the pricepoint in Germany, 
BUT
There were some things which I liked a lot... For me haptics and grip are important too and
the 5D Mark iii just melted into my hand. ;D
The touch dial is really great and the control with the, let me call it "JOYstick", was very intuitive.
I just don't like were Nikon placed the ISO button.
I like to fiddle around with settings : and Canon is just faster for my taste.
There are other tiny, little, maybe for you unimportant, things like, well call me stupid, but for example I like the orange backlit at dim light compared to the greenish one from the Nikon Topdisplay.
My hand and feel is not made for the Nikon design, thats what I noticed again!

Regarding DR,
I can and will compensate some DR in post processing.
I like the HDR blending, autoalign(!) of the 3 photos, for me, who frequently quickly does handheld shoots, its a new step forward.
I like the 2 shoots comparison on the large screen.

When I touched the 5D, I was reminded of one of the reasons I went with Canon, its the haptics, grip & control. 
For me making photos is not a job, its a joy. 
Still my budget is tight, so I'll have to wait a bit. But I think everybody who is currently concerned about what to do,
Try To get hold of the cam and really focus on the things you really need and prefer. Then forget about all the forums.
In the end I noticed its me taking the photo, not the cam, 
if I have fun then I'm happy. 

Just my 2 cents I wanted to share


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## LetTheRightLensIn (Mar 13, 2012)

It is to early to say for sure, but it seems like there may be a way to filter out most of the banding from the 5D3 unlike with say a 20D,30D,50D,5D2, etc. It seems like they may have eliminated most of the banding that varies shot to shot and mostly left it with a type of banding that may be relatively consistent shot to shot. It is definitely way to early to be sure though. But there are hints of promise.

You'd need a RAW converter that had a new option to feed certain information or a pre-processor to alter RAWs before feeding them to regular programs (as to the former, who knows if any companies would offer the options, as to the latter it can certain be coded no question at all). But again, still to early to say.


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## etto72 (Mar 13, 2012)

I would like everyone to make a simple consideration.....
Looking at the last 4 Canon sensor generation
-1Ds mk II, 5D,
-1Ds mk III,1D mk III,5D mk II, 40D
-1D mk IV, 7D
-1DX, 5D mk III
Lets look at the pixel pitch and at the equivalent DR values for each generation:
5D Pixel size 8.2 = 9.2 DR
1DS mk III Pixel size 6.4 = 11.3
5D mk II Pixel size 6.4 = 11.1
40D Pixel size 5.7 = 11
7D Pixel size 4.3 = 9.8
1D mk IV Pixel size 5.7 = 12
1DX Pixel size 6.9 = ?
5D mk III Pixel size 6.25 = ?
As you can see each generation gave an increase in DR except with the 7D wich has an extremely smaal 4.3 pixel pitch size
Last generation sensor gave a 12 EV with 5.7 pixel size
The mk III has 6.25 pixel size
Even if Canon didn't progress in DR with the newest sensor engineering...
..... I have really hard time to believe that with the 5d mk III with 6.25 they can't get same or better DR results with a sensor that has 5.7 !!!!
Time will tell....
Thanks
Ettore


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## wickidwombat (Mar 13, 2012)

So here is a question 

Does anyone actually know what the useable dynamic range of any of these cameras is?
I'm not talking about the infinite naval gazing number crunching analytical sort i'm taking about where the line gets drawn between "yeah that looks good" and "OMG that pattern noise just tore my left eyeball out"

Its prettysubjective isnt it? so the line is going to be different for everyone

and then there is all the third party Noise reduction gear out there which can salvage something that was fairly poor and make it acceptable extending that range of use. I dont think comparing things like this soley based on some numbers is very wise.


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## well_dunno (Mar 13, 2012)

etto72 said:


> Last generation sensor gave a 12 EV with 5.7 pixel size
> The mk III has 6.25 pixel size
> Even if Canon didn't progress in DR with the newest sensor engineering...
> ..... I have really hard time to believe that with the 5d mk III with 6.25 they can't get same or better DR results with a sensor that has 5.7 !!!!


+1 to that, mark 3 has bigger photosites thanks to the gapless microlens sensor tech which should benefit both DR and ISO performance of the cam. If there is no improvement on those, I do not think it would make 5D mark 3 a bad camera still, considering all the other improvements, but it would make it difficult to justify the price tag IMHO...


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## Radiating (Mar 13, 2012)

etto72 said:


> I would like everyone to make a simple consideration.....
> Looking at the last 4 Canon sensor generation
> -1Ds mk II, 5D,
> -1Ds mk III,1D mk III,5D mk II, 40D
> ...




I think it's worth mentioning that using raw data to discuss low iso banding and dynamic range is VERY VERY misleading.

The usual testing methodology simply determines the lower end of the dynamic range as the point at which the noise overwhelms the rest of the data, ie a signal to noise ratio.

The issue with low iso banding is not so much that Canon's cameras have excessive noise at low iso, they do not have especially excessive noise, and the data proves this at only slightly more than a 1 stop difference between Canon and say Nikon. The issue however is that this low iso banding noise CANNOT be removed because noise reduction algorithms treat pattern noise as detail and do not remove it.

Noise reduction algorithms are currently good for about 2-5 stops of noise reduction depending on how tolerant you are of losing detail.

So while on paper the 5D II/III have aproximately a fantastic 11+ stops dynamic range. In the real world they have an earth shattering 3-6 stops less DR than tested because NR is ineffective on low iso banding.




wickidwombat said:


> So here is a question
> 
> Does anyone actually know what the useable dynamic range of any of these cameras is?
> I'm not talking about the infinite naval gazing number crunching analytical sort i'm taking about where the line gets drawn between "yeah that looks good" and "OMG that pattern noise just tore my left eyeball out"
> ...




Hope that also answers your question.


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## LetTheRightLensIn (Mar 14, 2012)

etto72 said:


> I would like everyone to make a simple consideration.....
> Looking at the last 4 Canon sensor generation
> -1Ds mk II, 5D,
> -1Ds mk III,1D mk III,5D mk II, 40D
> ...



none of those results are normalized


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## LetTheRightLensIn (Mar 14, 2012)

wickidwombat said:


> So here is a question
> 
> Does anyone actually know what the useable dynamic range of any of these cameras is?
> I'm not talking about the infinite naval gazing number crunching analytical sort i'm taking about where the line gets drawn between "yeah that looks good" and "OMG that pattern noise just tore my left eyeball out"
> ...



the relative, which does better than what, is easily defined (ignoring banding) but sure the amount you find acceptable is subjective, taht's something else (but if one has more measured than another it will also have more by whatever your subjective opinion is than the other one, so that is why it is wise, because it makes it easy to compare in standard way)


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## Tammy (Mar 14, 2012)

http://www.arekgmurczyk.pl/tag/roadshow-nikon-d4-i-d800/

are you able to calculate the D800 DR from this set?


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## jrista (Mar 14, 2012)

etto72 said:


> I would like everyone to make a simple consideration.....
> Looking at the last 4 Canon sensor generation
> -1Ds mk II, 5D,
> -1Ds mk III,1D mk III,5D mk II, 40D
> ...



Where in the world did you get those numbers? They are inconsistent with both primary sources of data for whats technologically possible (DXO) and most likely possible in the real world (DPR). Real-world data is more subjective, so if we just take DXO data, which is more objective, the numbers become:


*Gen.**Model **Pixel Pitch **Screen DR **Norm. DR **Q.E. *15D C8.0410.7711.1325%11Ds II7.0510.7911.3430%240D5.6310.9911.1833%25D II6.3911.1611.8633%21D III7.2011.5011.7029%21Ds III6.3011.2511.9731%37D4.1611.1211.7341%31D IV5.7011.4611.9544%45D III6.25????(47%)?41D X6.95????(47%)?


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## jrista (Mar 14, 2012)

Ardea said:


> looks like the DR is the smae regardles sof the body. There is not advantage in FF over 7D in IQ and dynam,ic ranger!



On a normalized basis, not much. On a native basis, yes, DR has improved by over 2/3rds of a stop over 3 generations. Quantum efficiency has also consistently improved generation over generation (I think I've been conservative with my estimates for Canon's latest.) If we extend that to a fourth generation, one would expect a minimum of about 1/3rd of a stop improvement in DR for the next generation unless Canon has some physical limitation in their electronics that simply prevent achieving 12 stops total.


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## LetTheRightLensIn (Mar 14, 2012)

Ardea said:


> looks like the DR is the smae regardles sof the body. There is not advantage in FF over 7D in IQ and dynam,ic ranger!



Not really for dynamic range. For FF though you can get better SNR what with the 2.5+ times larger area over which to collect light.


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## Aglet (Mar 24, 2012)

[size=14pt]*Pixel-Peepin' Pushing Plaid Shadows update
*[/size]

Preliminary subjective evaluation conclusions are farther below.

I've compiled dark frame raw files for the following cameras:

Canon DSLRs: 40D, 50D, 60D, 7D, 5D2, 5D3, 450D, 1000D
Canon PowerShots: G3, G5, G6, G11, G12
Nikon: D90, D5100 (seeking D800, D300/s)

As much as possible, these were all done using Manual mode and the following settings:

- T = 1/200s
- A = f/16
- iso base + all std values, 100, 200, 400, etc
- WB = daylight
- all in-camera noise reduction disabled
- all in-camera tone-curves disabled (Auto Lighting Optimiser, D-Lighting, etc.)
- capped lenses and as dark an environment as possible (G-series and 5D3 were under less than ideal conditions)


Also, in-camera dark frame subtraction was tested using iso 100 and 800 wherever possible:

- On SLRs this was a 2 second exposure at both 100 and 800 iso with, and without, long exposure noise reduction.

- On the G-series it was done at base ISO and +4 EV iso at 1 second and 2 second exposures. These cameras automatically turn on dark frame subtraction at 1.3 seconds or longer, if I remember correctly.


Post processing was done with ACR, using DNG converter 6.7rc1 for the 5D3 files.

Supported raw file vs converted to DNG files compared look virtually identical on the ones I tested so let it roll as equivalent.

Import processing was preset to:

- 0 black level clipping (so as not to lose any of those noisy pixels)
- +4 EV exposure compensation
- 2010 Adobe default standard style instead of any of the camera-specific tone/color options
- imported as 16b/color
- WB as shot (DL) (some anomalous K amounts showed up despite the daylight settings, looking into that later (4800-5600K)


- further +3 EV added under PS CS5 Image/Adjust/Exposure to really bring up the dark noise to very visible levels


Comparing the overall amount of noise, and its subjective quality, was very illuminating!

WOW!

I can now really see the weaknesses and strengths of various camera bodies when it comes to different kinds of shooting conditions and post-processing expectations. Since I often shoot scenes with very high DR I want to be able to take a single shot, exposed to retain hilite info and PP to bring up shadow details. I don't want to do this with multiple-shot HDR methods since it's often not suitable or convenient for non-static scenes.


As I'd expected, the noise quality of my old 40D is more amenable to large shadow pushing amounts than newer bodies like the 7D.
The 60D was somewhere in between, 50D was kind of like the 40D but much higher overall noise. 450D was surprisingly decent, 1000D was pretty limited.
PowerShot G11 showed considerable room to push shadows while D90 and D5100 Nikons showed far more room and virtually no detectable patterning to the noise at even moderate to high levels of shadow push. 7D shadows could not be pushed much at all at low iso due to tremendous amounts of fine vertical banding (due to it's doubled readout channels?) but is better at 800 iso and up as random noise starts to dominate. This fine banding can be visible in large prints.

When comparing 5d2 to 5d3, the 5d3 shows only about 0.3 EV less overall low-iso dark noise as perceived by overall brightness and histogram of resulting pushed image. 5d3's noise character, however, is somewhat less patterned (retains vertical, almost no horizontal banding) and may allow it to be pushed slightly more in post, perhaps an optimistic 1 stop improvement. 5d3's hi iso performance is pretty good, tho that's not something I normally need beyond iso 1600.

OTOH, D5100 can be pushed an extra 4.5 EV before its low iso files match the same level of total noise as the 5d2 but the D5100's noise is less patterned so could allow for even further pushing before hitting the limits.


This is all a rather subjective comparison, and does not lend itself very well to deriving actual DR numbers for any given camera but this is fairly representative of the kind of post-processing workflow I use for some kinds of shots that I do. Being able to now see these cameras compared like this gives me a good idea which one will be "the right tool for the job."
If I could reshoot all these bodies on a nice static scene example, like imaging-resource does,then an even better idea of the practical shadow pushing limits, using the hi-key areas as a normalizing exposure level, could be obtained. That would be closer to approximating real-world use and limits.

When I get more time to compile and organize actual image samples from all these tests into a layout where you can more readily see the effects I'll start a new thread on the subject using *Pixel-Peepin' Pushing Plaid Shadows* as the topic. 


The recent release of DxOmark data on the D800 is tantalizing, but I still want my own dark file samples if I can get my hands on one.
And let's hope Canon can meet the challenge that Nikon/Sony have thrown down... SOON.


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## Astro (Mar 24, 2012)

jrista said:


> There are slight differences in banding vs. fixed pattern...I believe they are caused by different gains at different parts of the pipeline. The fixed pattern stuff is finer and cross-hatched, and pretty much always the same in every frame. Whatever causes banding is different, and the banding can change frame to frame. As far as I can tell, the fine, FIXED PATTERN noise is gone in the 5D III.



FPN is caused by physical non-uniformities at sensor level. 
it can be easily removed because it does not change.


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## sndan (Mar 24, 2012)

http://www.flickr.com/photos/trentchau/6861371280/#sizes/l/in/set-72157629637172995/

A GREAT DIFFERENCE


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## Aglet (Mar 24, 2012)

random banding is more likely caused by power supply instabilities or other system noise creeping into the sensor signal path. comes down to proper electronics design and shielding.
I found noticeable random horizontal banding in some older bodies I tested, like the 40D, when pushing shadows.
Makes me wonder how well it'd perform if the internal power supplies and shielding were improved...


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