# DR and RAW bit depth on Canon's forthcoming...



## jrista (Feb 9, 2012)

With all the details flying around about Canon's forthcoming releases, I'm curious if there has been anything about dynamic range and RAW bit depth for anything announced or rumored? Despite the fact that Canon claims 14-bit capability, they have not seemed to make fully effective use of it so far, with most of their cameras topping out in the 11-12 stops of DR range. Does anyone know what the DR of the 1D X is...will it have a true 14 stops like most of the recent Nikon cameras? Have there been any rumors stating DR for the 5D II successor or this possible new 40mp model?

It would be fundamentally disappointing for Canon to miss the mark AGAIN on dynamic range and keep all their loyal customers bound to an 11.7-stop limit on DR when the competition is blowing that out of the water. Of all the various improvements Canon could make, having thought about it the last few days, I would take a 5D III with the same resolution as its predecessor, same ISO range, and only the 60D's 9-point AF...if I could have better dynamic range. An extra two stops would do more for my landscape photography than anything else...including unbelievably high ISO, the 7D or even 1D X AF, etc. I could stop wasting time setting up and adjusting the single 2-stop GND filter I usually have to use, and just spend my time capturing the beauty before me as-is.


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## Curmudgeon (Feb 25, 2012)

jrista,
I posted a very similar comment on the thread about reaction to the firmed-up specs of the 5D3. (I too begged for two more stops of DR--fat chance.) To me the lack of dynamic range in the 5d2 is its most glaring deficiency-- and the 5D2 is probably one of Canon's better performers in this regard. And yet there seems to be very limited concern about dynamic range among the users of this forum. I think I am the 393rd reader of your post, and the first to make a response.

For me DR is a constant problem--much more so than autofocus or high ISO performance. Any time there is a horizon in my composition it's a pretty good bet that something is either going to be blown out or blocked up. As you say, there are many occasions where neutral density filters, AEB/HDR, even a tripod, are not practical because of subject movement, location, etc. What's really disturbing is to compare my current efforts to some of my 40-year-old prints from 35 mm film. I don't expect two stops in the new 5D, but if there isn't at least one real stop, I'll spend my photographic budget on lenses. The 24L TS-E is looking mighty tasty.

I was going to open a thread on this subject myself, but I'm new to this forum and before flogging what I assumed was a thoroughly dead horse, I did a forum search. Until you started this thread I found incidental snippets, but not one thread devoted specifically to DR issues.

You've raised the question in relation the next 5D; if it isn't hijacking the thread I'd like to broaden the discussion to the whole issue of DR in digital photography. Is this a historico-political problem? Are we in this pickle because we haven't made our needs clear to the manufacturers? There are ten demands for better high ISO performance, more resolution, or faster autofocus for every complaint about limited dynamic range. We've seen major advances in all those other areas. If Canon thought we were really bothered by the limited DR of their products would we see that two-stop DR improvement in the 5d4?

Maybe it's a specialized problem, primarily of concern to landscape photographers? I can see where DR might not be as big an issue for studio photographers, where the photographer and not nature is in charge of the light as well as the composition. Do wildlife shooters miss the dynamic range of film?

Or is this a technical problem? Digital photography has made amazing strides over film in areas like resolution, maybe even color rendition. Modern high ISO performance makes 20th century efforts to "push" film look like something out of the bronze age. On the other hand, perhaps DR is particularly daunting challenge for CMOS technology. Would you have to give up something else to realize a significant gain in DR? Then too, is there a technical reason why Canon lags behind other manufacturers in this area?

All of this leads back to your question of whether the next few generations of digital cameras hold any significant promise for improvement in DR. Do we just have to get in Canon's face, or are we condemned to wait for an as-yet undreamt-of technology? It would be interesting to hear on these issues from people knowledgeable about the historic and technical aspects of photography.


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## jrista (Feb 25, 2012)

@Curmudgeon:

It might take some real doing to get more than 14 stops of DR...that would mean truly pushing into the realm of full 16-bit RAW, and thats not an easy feat...it certainly wouldn't be cheap. However, we already have a load of "true" 14-bit sensors on the market from Sony, used in both Sony cameras as well as Nikon cameras. They are achieving over 13.8 stops of dynamic range. Given that, its obviously possible to achieve close to the full 14 stops that should be possible with 14-bit sensors and image processing chips.

Why Canon is stuck at 11.7 stops at most is really mind-boggling to me, especially given how much they tout their full precision 14-bit image processing pipeline in their DIGIC 4 and new DIGIC 5/5+ chips. Slapping a number on the side of a chip is rather meaningless if you really aren't utilizing the additional capabilities and headroom, and over the last couple of years, Canon has consistently come in second-place to Nikon when it comes to dynamic range and color depth (which really means color reproduction accuracy...and while the difference is not huge (rather largely imperceptible to the human eye in rough comparisons), it is meaningful...particularly to those who require accurate color reproduction.)

Its certainly possible to achieve 13.8 stops of DR and over 23 bits of color sensitivity/accuracy with a current-generation sensor. There is nothing to indicate Canon couldn't achieve the same, and if their new sensors in the likes of the 1D X and 5D III don't show any marked improvement once DXO tests come out...then Canon is making a choice not to improve on those fronts (to the bafflement of their customers, for sure!)


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## PinkFish (Feb 26, 2012)

Despite the fact I really prefer the ergonomics of Canon bodies (I always think that modifying Nikon settings while in the field, is a pain in the butt), I feel more and more disappointed by Canon "politics". Body after body, the upgrades are either a small increase of features, or an attempt to catch up the competition (e.g AF, wireless flash). But no real improvement on DR.
Alas, at least in French forums, most of photogs praise the high ISO of 5DII, but few lament its poor DR. Have the last Canon landscapers fled to the competition? Or is it simply a denial ? "Au royaume des aveugles, les borgnes sont rois !"


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## dtaylor (Feb 26, 2012)

jrista - DxO DR tests are highly inaccurate. You can disprove them yourself by simply buying and shooting a Stouffer transmission step wedge.

I don't know of any Nikon or Sony sensor which can capture 13.8 stops on a transmission step wedge. Canon's 18 MP crop sensor yields about 10 stops, while Nikon's 16 MP crop sensor yields about 11. The 5D2 is good for about 11 stops, as are Nikon's FF sensors.

In all of the above cases, if you're willing to dual process and merge your RAW file, and accept some additional shadow noise, you can probably squeeze 1 more stop out of the file, at least with Adobe's converter.

I don't see any great difference between Canon and Nikon bodies in this regard. On crop Nikon has a slight edge because their 16 MP sensor is one year newer than Canon's 18 MP sensor. I'll be curious to see what the new generation of sensors can do. But I think we're a couple generations away from a sensor which can handle, in a single exposure, landscapes with a wide scene brightness range without filters or HDR. Even color portrait films generally can't handle those scenes, and B&W only could with specialized processing and printing.

While I'm on the topic, I also consider DxO's color tests to be meaningless. Color differences between modern DSLRs are one or more orders of magnitude less than differences introduced by RAW converters, post processing, monitors, printers, and even paper choices. Sensor color differences are, with rare exception in narrow applications, effectively invisible to humans.


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## LetTheRightLensIn (Feb 26, 2012)

dtaylor said:


> jrista - DxO DR tests are highly inaccurate. You can disprove them yourself by simply buying and shooting a Stouffer transmission step wedge.
> 
> I don't know of any Nikon or Sony sensor which can capture 13.8 stops on a transmission step wedge. Canon's 18 MP crop sensor yields about 10 stops, while Nikon's 16 MP crop sensor yields about 11. The 5D2 is good for about 11 stops, as are Nikon's FF sensors.
> 
> ...



Have you ever manipulated a low ISO D3x or D700 file and then gone an manipulated one from Canon? The difference is every bit as real as DxO says it is.
Hopefully Canon can finally match it and it's not something that is only possible with something needing a Sony patent (they use column ADC on their sensors that have the amazing low ISO DR) and/or that Canon can do what is needed with their current fab.


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## Curmudgeon (Feb 26, 2012)

Thanks for the info, jrista. I have to say I was hoping your thread would crystallize feelings and unleash a torrent of pent-up frustration among the Canon faithful.

Guess not. This thread is in its second day; it's gotten billing on the masthead, and there are a total of six responses. Meanwhile, the thread speculating about other features of the 5D3 is probably going on 40 pages. 

And you know, I'd forgotten about all the fuss Canon made about the 14-bit rendering of the 5D2 and what a big difference that was going to make. It didn't--and the preliminary talk from Canon about the improved jpeg performance of the IDX makes me worried that they may be planning to finesse the issue again in the coming models.


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## te4o (Feb 26, 2012)

I'd like to join your discontent with the DR of the current Canon line. The well praised 5dII is just shocking when pushed a bit more energetically in PP. I read here about QE and SNRs etc and it is obvious that it has an old-fashioned sensor whose attraction in 2008 was the resolution. But the resolution is lost in the noisy dark areas. I hope very much as you do that the new generation of sensors will deal better with the DR of our subjects - there was a mention by someone who used the 1DX on one of the stands and got the feeling of shooting HDR - so there is hope. The question is whether the 5D line will take the full advantage of these new sensors or just part of it to make the 1D series still attractive. Who knows...
One small advantage of the rumored 6.9 FPS is that it makes HDR on windy days easier : And the 4 stop AEB adds to it. But as you said, there is no substitute for a single shot of a good quality high IQ high DR. I am happy to pay for it but I am not happy to pay for 36 miserably performing MP giving me sharpness I don't need! Because it is NOT THE SHARPNESS which catches our attention, more it is the quality of light capture in DR and colors (next to subjects, composition, rarity etc etc all shooters' components)


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## Mt Spokane Photography (Feb 26, 2012)

You don't need to do the Stoffer Wedge Test, its been done many times. You can see the usable DR range of competiting camera bodies here:

5D MK II 8.4 EV
Nikon D700 7.8 EV

http://www.dpreview.com/reviews/CanonEOS5DMarkII/page25.asp

You can get more by manipulating RAW files, but the images tend to look flat and ugly.

I'd also like more DR, but, so far, no one seems to match film.


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## DianeK (Feb 26, 2012)

My 60D is my first digital camera. I was an active photographer 20 years ago mostly shooting slides, then completely dropped out of the hobby. My re-entry into the hobby has been very disappointing...I still had fond memories of Kodachrome 64. Seems now I am shooting a lot of AEB triads and spending considerable time in PP to increase dynamic range. It would be very nice to not have to do that.
Diane


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## jrista (Feb 26, 2012)

Mt Spokane Photography said:


> You don't need to do the Stoffer Wedge Test, its been done many times. You can see the usable DR range of competiting camera bodies here:
> 
> 5D MK II 8.4 EV
> Nikon D700 7.8 EV
> ...





Just to make sure everyone understands the 8.4 annd 7.8 EV's from above...those are _attenuated_ results (i.e. has a picture style...or more accurately a tone curve...applied) based on JPEG images. If you scroll down the same page linked in Spokanes post, under the RAW headroom area, it mentioned that RAW images get additional DR...and in the case of the Canon 5D II, its about 10.3 stops. Conversely, the D700 achieves 11.6 stops when tested with RAW. The dpreview tests are different (and less precise, although probably more realistic) than DXO's tests. 

I would say its difficult to directly compare results from dpreview as a measure of low-level camera capabilities, but a great way to measure real-world capabilities. Conversely, I would say DXO is a poor way to compare cameras from a real-world standpoint, but it is an accurate way to compare minor low-level differences in hardware capabilities.

Regardless, both DXO and dpreview indicate that, when using RAW, Nikon (and Sony, for that matter) cameras get better dynamic range than Canon...by over a stop in most cases, and as much as two for the best Sony sensors.



Mt Spokane Photography said:


> You can get more by manipulating RAW files, but the images tend to look flat and ugly.
> 
> I'd also like more DR, but, so far, no one seems to match film.



Thats not entirely accurate. You have more headroom with a RAW image. They are still attenuated with a tone curve, so contrast improves over the unprocessed native sensor data (which you can generally only see with open-source RAW processors...ACR/Lightroom and Aperture all apply non-linear base processing to all RAW images). You have a good 1.5 to 2 additional stops of dynamic range headroom with RAW, though, so you are less likely to blow out highlights when shooting, say, a sunset, as you would be if you had two stops less DR. I'd rather have that 10.3 stops than the 8.4, and having 11.6 stops of real-world DR would be bliss. The extra headroom means making photographs is "safer" from hitting that hard limit that digital sensors have on the highlight end of things. In film, highlights "blow out" slowly (its analog after all), there is no hard digital limit, which is why film is still touted as having better highlight flexibility than digital.


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## LetTheRightLensIn (Feb 26, 2012)

Mt Spokane Photography said:


> You don't need to do the Stoffer Wedge Test, its been done many times. You can see the usable DR range of competiting camera bodies here:
> 
> 5D MK II 8.4 EV
> Nikon D700 7.8 EV
> ...



DPR test is ridiculous, it depends on nothing other than what tone curve is in the jpg setting.


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## mkln (Feb 26, 2012)

I have a hard time believing DXO and some of their ratings, often times they look so unrealistic I could shit in my pants. 
for example the rating they give the 70-200 II is low, much lower to what they give to 85L. truth is, I have both and find 70-200 as good as 85L (of course they measure max performance throughout the aperture and zoom range, and I can't agree with them on that)

HOWEVER, their sensor ratings seem to be accurate.
I have a 5d2 and a NEX 5N. they say the 5d2 should have less DR than 5N, and indeed that's what I perceive.

When I bought the 5N I liked its size and its being lightweight. Then I took some pics and I was amazed at how it didn't blow up the highlights. only later did I check on DXO to see what kind of DR they measured on it.
turns out it has 2/3 of a stop more than the 5d2. and I really think that's the case. 
now I enjoyed the 5N shots so much that I will not upgrade to 5d3 (not at that price) unless it shows significant DR improvement over 5d2. 
and by significant I mean at least 1 stop. Sony has proven it possible... why can't Canon?

I really don't understand all that fuss about FPS. if you want fps just buy a used 1D3, or a 1D4. I bet their prices are around what the 5d3 will be (new). and they have the "extra reach" that sports photogs seem to love.

Also I don't understand why people look at the D800 and only see 36mp and say "omg it's too much it's going to be blurry/poor high iso/other" when it will have the same pixel density as my 5N and:
- great DR
- my 5N does not produce blurry pics AT ALL, required shutter speed is not significantly different from what I use with the 5d2
- high iso on my 5N are great. in quantity terms not as good as the 5d2 (FF vs. APSC, that's a given), but in quality terms it's much more manageable (no banding). If I were to extend the 5N sensor to full frame (that's a D800) and to resample the pic to 21mp, I bet the result would be much better than the 5d2.

so yeah, D800 has high mp, but it also has an amazing sensor that excels in everything, DR included.
and yes, canon fanboys are blind to DR, they only want FPS and AF (btw, good AF is the very least we could expect from a $3500 camera, duh!!)


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## Curmudgeon (Feb 26, 2012)

LetTheRightLensIn said:


> dtaylor said:
> 
> 
> > Hopefully Canon can finally match it and it's not something that is only possible with something needing a Sony patent (they use column ADC on their sensors that have the amazing low ISO DR) and/or that Canon can do what is needed with their current fab.
> ...


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## jrista (Feb 26, 2012)

Curmudgeon said:


> When I consider the relatively slow progress Canon has made in DR, I also sometimes wonder if Sony has some recent patents that Canon is having difficulty circumventing. Canon is now competing with some heavy hitters in the electronics industry. LTRLI, can you expand a little on what column ADC is?



Its actually called Column-Parallel ADC. Normally, a single ADC (analog-to-digital converter) is used to convert all of the analog signal read from a sensor into a digital counterpart. Sony has a patent (I believe, anyway) for a CMOS design that uses multiple ADC's in parallel for each column of pixels, theoretically improving readout throughput considerably.

I am not exactly certain how Canon's 1D X sensor works from an actual hardware layout level, but it does have 16 parallel primary read channels, which in turn are split into two groups of 8, each group of which is handled by a dedicated Digic5+ processor. I would imagine that would require at least as many ADC's, one per read channel. I am not sure if Canon's approach reduces read noise levels to the same low level as Sony's, but if they are really able to reach a native ISO 51,200 with the same noise level as present at ISO 6400 before, it must have improved it enough.

I can't say whether the 1D X has column-parallel conversion on each and every pixel column, but seeing as Sony hasn't yet achieved the full theoretical 28fps @ 18mp that should be possible, I figure their C/P ADC isn't quite as good in real life as it sounds on paper. 



Curmudgeon said:


> There were also some older technologies that had some success in expanding DR. As I recall, a few years back Fuji was building DSLRs that featured ganged pairs of high and low sensitivity pixels. Again (if memory serves) Fuji was in the unfortunate position of having to retrofit their technology into Nikon D200 bodies, but apparently the cameras actually did have more latitude than the CCD sensors of the time and enjoyed some popularity among wedding photographers. Anybody have any experience with those cameras or know why that technology faded from the scene?



Fuji's diagonal grid with extra luminance-only sensels did pretty much the same thing that microlenses does on Canon sensors. It helps utilize otherwise wasted space to gather light that would have been reflected by wiring or simply unused wafer surface. With the advent of gapless microlensing, there is very little sensor surface that can't be used to gather photos and direct them to a photowell. It would actually be fairly difficult these days to develop a sensor that had luminance only pixels without taking a step back from where we are with microlensing. Front-illuminated sensors still have obstructions in the light path to the photodiode itself, which can either absorb photons and convert it to heat or noise, or reflect them back out of the sensor. A back-illuminated sensor would reduce the chances of absorbing or reflecting photons before they are captured by the photodiode. Beyond back illuminating...I think the only real improvement would be to move to a layered design like Foveon. Thats the only major remaining drawback of the bayer sensor design, however at the densities they are achieving today vs. the highest density Foveon sensors, the difference is largely moot (an 18mp APS-C/45mp FF has enough density that for realistic presentation formats...moving to a lower-resolution Foveon sensor wouldn't offer any realistic benefit outside of _potential_ for improved DR, reduced color moire, and greater color sensitivity.)


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## Flake (Feb 26, 2012)

Reading some of these posts makes me think that there are some photographers who think it should be realistic to take photos of the setting sun and still keep details in the shadow areas! Hardly any mention of HDR, and no mention at all of specialised filters.

Back in the days of film - and DR comparison of film and digital is incredibly difficult, companies like Lee & Cokin were producing the same filters as they are today. That's photographic technique to improve the dynamic range, and even with the dynamic range improvements being mentioned on the thread, it's still not enough to negate the use of ND grads .

It also makes me wonder if this is a fault of the camera or the monitor? Often I have images which appear to have a blown sky, and increasing exposure in PP of course makes it worse, but using the ND grad tool reveals that the camera has indeed captured all the detail in the sky, it's just that the exposure level needs to be reduced so it can be viewed. Here is a piece from Wikipedia on the subject:

_The most severe dynamic-range limitation in photography may not involve encoding, but rather reproduction to, say, a paper print or computer screen. In that case, not only local tone mapping, but also dynamic range adjustment can be effective in revealing detail throughout light and dark areas: The principle is the same as that of dodging and burning (using different lengths of exposures in different areas when making a photographic print) in the chemical darkroom. The principle is also similar to gain riding or automatic level control in audio work, which serves to keep a signal audible in a noisy listening environment and to avoid peak levels which overload the reproducing equipment, or which are unnaturally or uncomfortably loud._


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## Mt Spokane Photography (Feb 26, 2012)

LetTheRightLensIn said:


> Mt Spokane Photography said:
> 
> 
> > You don't need to do the Stoffer Wedge Test, its been done many times. You can see the usable DR range of competiting camera bodies here:
> ...



You still get a tone curve processing in RAW. you have to manulipate it to get a little more DR. Then images tend to look flat. DPR tells you the real world info. Its like a statement of what you get off the showroom floor whan you buy a automobile, its what many, if not most get.


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## NoFitState (Feb 26, 2012)

I'm really not that well informed on dynamic range. Had a quick search for some examples of comparisons between Nikon & Canon and found this video. I have no idea how indicative it is of the real world performance of both cameras, but its a fairly significant difference in my eyes.

http://testcams.com/blog/2011/05/03/nikon-dx-vs-canon-aps-c-dynamic-range/

Being able to just expose for highlights (and pull up the shadows in post) would make a big difference to some of the photos i've taken. Really does seem like it should be higher on the priority list for a lot of us


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## Kernuak (Feb 26, 2012)

I've said before, that lab tests are pretty meaningless, unless they reflect the real world, after all, as photographers, we are judged by what we achieve, not by what could be theoretically achieved. At work, we use analysers and I remember a number of years ago, I was working through a tender specification. The company supplying the analyser in question quoted a figure of 105 samples/hour throughput. When challenged, they said in reality, it averaged around 90 samples/hour. In reality, it is actually closer to 70-75/hour. It is very rare that any electrical or mechanical goods achieve theoretical values and the variation between reality and theory, is highly variable. Often, it is the equipment with the higher theoretical range, that is furthest from reality.
Flake mentioned the use of HDR and grad filters. As a landscape photographer, I know that even with an extra stop of DR, there is no way that I could capture most scenes without using grad filters, unless I make some compromises. In fact, photography is all about making compromises, that is what sets the greats apart from the merely good. If you could simply point a camera at a scene and get perfect results, then everyone would be doing it. The true masters, know how to manipulate the available light, to get near perfect results. Sometimes, you actually want blown areas for added effect, if you have a massive dynamic range that captures everything, how would you achieve that? Don't get me wrong, I would welcome more dynamic range, especially for wildlife, but I think we also have to be realistic and not accept suggested facts and lab tests too readily. The only sure way to make an accurate comparison, would be to shoot the same scene, with the same exposure value, at the same time, then look at the differences. The human eye is a precision instrument, it will detect meaningful differences if they exist. If it can't detect them, then they are irrelevant, no matter what tests tell you. It's not much use having an extra stop of DR, if your meduim of choice can't show it. I suspect that you'd need an expensive Spectraview type monitor to see any differences. Different papers will also have different DR, some papers have a higher DMax than others, allowing them to show more shadow detail.
A few years ago, I decided to have a play with slide film, as I'd never shot with it before, having only used negative film in the past. I did some digging at the time and was reading that slide film had a DR of around 5-6 stops, compared to 10-11 for negative film. My results with slide film clearly showed less DR than I could get with digital.
I did a bit more digging just now. The figures for slide film ranged between 5-6 and 7-8 stops, while negative film was consistently in the 10-11 stop range. I also came across this article, which looked at comparisons between digital and film, both theporetically and in practice. There are some flaws in the testing, as it involves scanning of the film images, which does increase noise and probably some other effects, but it does show that it isn't as clear cut as it is sometimes made out to be.

http://www.clarkvision.com/articles/dynamicrange2/


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## Tijn (Feb 26, 2012)

Kernuak said:


> The human eye is a precision instrument, it will detect meaningful differences if they exist. If it can't detect them, then they are irrelevant, no matter what tests tell you. It's not much use having an extra stop of DR, if your meduim of choice can't show it. I suspect that you'd need an expensive Spectraview type monitor to see any differences.


See the above video and you'll understand why you're thinking too quickly. The human eye has MASSIVE dynamic range. We can see out of a window and still see every detail in the dark room we're in. When taking a photograph out of a window, the result is that the room will be severely underexposed. We need to push up its exposure in post-processing to recover any detail in the underexposed area. Just simply overexposing shadows will show you a difference in dynamic range, which by the way is a real-life-situation thing, as that's extremely common in postprocessing images. The fact that cameras lack this dynamic range is the whole reason why HDR photography exists.
Cameras are still very far from having the dynamic range or sensitivity of the human eye.


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## Flake (Feb 26, 2012)

Tijn said:


> Kernuak said:
> 
> 
> > The human eye is a precision instrument, it will detect meaningful differences if they exist. If it can't detect them, then they are irrelevant, no matter what tests tell you. It's not much use having an extra stop of DR, if your meduim of choice can't show it. I suspect that you'd need an expensive Spectraview type monitor to see any differences.
> ...



Except that the human eye does not work in the same way as a camera! Persistence of vision means that we are able to scan a scene and the iris is able to adjust its aperture to allow less light to reach the retina, giving the impression that we have a huge dynamic range when we do not. In addition rods and cones in the retina allow difference sensitivities to light, and we can to some extent see in very low light, albeit only in black & white.

The human eye has an approximate focal length of 50mm and around 50MP equivalent, having two of them on the front of the head means we have stereoscopic vision and can perceive depth and 3D, again without two images a camera cannot replicate this.


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## Tijn (Feb 26, 2012)

Flake said:


> Except that the human eye does not work in the same way as a camera! Persistence of vision means that we are able to scan a scene and the iris is able to adjust its aperture to allow less light to reach the retina, giving the impression that we have a huge dynamic range when we do not.


I'm aware of that. And yet, we _do_ have a very large "dynamic range" even when counting in that difference. We can see stars and we can see outside on sunny days, but not at the same time. Still, we _can_ see outside a window and at the same time keep seeing detail of the room inside. Without pupil adjustments. My camera won't do that as well as I "do", at least not without post-processing.


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## tt (Feb 26, 2012)

Tijn said:


> Flake said:
> 
> 
> > Except that the human eye does not work in the same way as a camera! Persistence of vision means that we are able to scan a scene and the iris is able to adjust its aperture to allow less light to reach the retina, giving the impression that we have a huge dynamic range when we do not.
> ...



Out of curiosity - what would be the resolution of the foveal vision?


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## KeithR (Feb 26, 2012)

As long as I can get from this:







to this:






And from this:






to this:






with my 7D, I don't see what the problem is - there's pretty wide DR in those.

Personally though, DR at the top of the histogram is what matters to me, and that seems to be Canon's priority too, I'm pleased to say:











(No idea why the "recovered" bike image is presenting small here, it's the same size as the underexposed one...)

And I suppose this post will get me some more negative karma from the children here...


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## Marsu42 (Feb 26, 2012)

KeithR said:


> with my 7D, I don't see what the problem is - there's pretty wide DR in those. Personally though, DR at the top of the histogram is what matters to me, and that seems to be Canon's priority too, I'm pleased to say:



... but there's a catch: I used to use the htp mode on my 60D on every shot until I realized that even the expanded iso range compresses the shadows so much that recovering them brings in much noise. Nowadays, I simply underexpose 1/3ev and shoot raw - the only drawback that highlight recovery in lightroom torpedoes clarity when used at the same time.

However, I agree with you that the current 18MP sensor has enough headroom for most shots, and if not it's in typical hdr situations when a bit higher dr wouldn't be of any use anyway.


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## Mt Spokane Photography (Feb 26, 2012)

KeithR said:


> As long as I can get from this:



The human eye can see much of the fine detail missing in the images, even after they are adjusted. Things can always be better.


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## thatcherk1 (Feb 26, 2012)

I think the main point of this thread isn't that we want to shoot the sunset without filters and expect perfect exposure from shadows to the sun itself. I think what people are wanting is Canon to produce a sensor with DR that other manufacturers have already achieved. It's more of a comparison to other brands and a worry that Canon will continue to fall behind with DR. In a day and age of "raw" workflows, people like the idea that they can shoot in the field, and spend hours and hours perfecting a digital grad filter rather than be stuck with a poor decision made when taking the photograph. Sometimes I'd prefer to just get it in the ballpark in the field, and not have to touch it much in post. But I certainly can't fault anyone who wants to perfect it later. With digital raw workflow we can achieve some beautiful (and realistic looking) images that would have been difficult or impossible in the days of film with only "in the field" and limited darkroom tools.

Also a note about monitors/photo paper, etc. In practical terms, people want a couple more stops of DR not so they can get some muddy looking image that shows 14 stops of latitude. The purpose is to smartly make adjustments in LR and PS to display those 14 stops in a beautiful way with things like the curve tool, or the grad/brush tools in LR. Or for others such as photojournalists, occasional under/overexposure happens, and more photos will be recoverable if there is more DR to work with especially with LR4(beta)'s exposure adjustment which is highly accurate to actual in-camera exposure adjustment.

Adobe's latest raw processing is exceptionally good at rolling off highlights similar to the way film does. It makes clipping sections of the image look much more pleasant. As soon as I start pulling exposure in LR, that nice roll-off begins to lessen until the clipping looks like crappy old digital. So any number of stops that are added to a camera's capability will only improve the beautiful film-like rolloff.

And as to a comment about how some images you want washed out, it's insanely easy to take even a 30 stop HDR and crush it down to 1 stop of range. It's never a problem to limit DR in post.


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## LetTheRightLensIn (Feb 26, 2012)

KeithR said:


> Personally though, DR at the top of the histogram is what matters to me, and that seems to be Canon's priority too, I'm pleased to say:



Most DSLR sensors are linear capture so there is no such thing as "at the top of the histogram" and the fact is you can't get out of a 7D image (and yes I have one) wht you can from a D7000 at ISO100.


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## LetTheRightLensIn (Feb 26, 2012)

Kernuak said:


> I've said before, that lab tests are pretty meaningless, unless they reflect the real world, after all, as photographers, we are judged by what we achieve, not by what could be theoretically achieved.



But they do! Have you seen what a heavily pulled D7000/D3x ISO 100 shots looks like compared to one from 50D or 5D2?



> Flake mentioned the use of HDR and grad filters. As a landscape photographer, I know that even with an extra stop of DR, there is no way that I could capture most scenes without using grad filters, unless I make some compromises. In fact, photography is all about making compromises, that is what sets the greats apart from the merely good.



But once you are into nearly 3 stops of usably better DR then it does start to make much more a difference in what things you can capture or not.



> It's not much use having an extra stop of DR, if your meduim of choice can't show it. I suspect that you'd need an expensive Spectraview type monitor to see any differences.



Not at all. In fact most of them are IPS and don't even have very huge contrast ratio compared to some cheap SPVA screens. But it makes a big difference either way.

And seriously if Canon had 3 usable stops better DR like it did back when, compared to Nikon, would all of you still be finding every excuse in the world why we don't need it and who cares??

Why would anyone, most of all a Canon user, NOT want Canon to fix this up???
I care because I have Canon equipment.


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## LetTheRightLensIn (Feb 26, 2012)

Mt Spokane Photography said:


> LetTheRightLensIn said:
> 
> 
> > Mt Spokane Photography said:
> ...



No you don't have to make it flat, you just apply special curves, maybe even different ones to different parts of the image and you can end up with rich contrast and color and nice detail without too much mush/noise/poor color and without weird over the top HDR look if you go about it right.

DPR doesn't come close to telling you the real world info. Even without using just a simple curve the in cam jpgs don't come close to the real story from RAW. You could easily chose a jpg style that would make any DSLR look better than any other from DR and then you coudl pick another one and reverse the results.


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## LetTheRightLensIn (Feb 26, 2012)

Flake said:


> Reading some of these posts makes me think that there are some photographers who think it should be realistic to take photos of the setting sun and still keep details in the shadow areas! Hardly any mention of HDR, and no mention at all of specialised filters.
> 
> Back in the days of film - and DR comparison of film and digital is incredibly difficult, companies like Lee & Cokin were producing the same filters as they are today. That's photographic technique to improve the dynamic range, and even with the dynamic range improvements being mentioned on the thread, it's still not enough to negate the use of ND grads .
> 
> ...



You are not reading the posts correctly then.


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## jrista (Feb 26, 2012)

I think everyone is largely missing the point of my original post. I want improved *headroom* in my photographs. I'm not looking to produce photos that are dull and flat and expose every last scrap of dynamic range a sensor is capable of. I am looking to have some buffering and room within which to push my exposures around. Its a _dynamic_ range...not a constant range. The whole point is to attenuate the raw image to look the way you want it to look _within_ that dynamic range (which means the final result will exhibit LESS tonal range than possible when utilizing the full, unattenuated DR the sensor is capable of), and have the freedom to shoot in scenes with broad contrast without too much fear of encountering the worst problem with _digital_ photography: *the hard highlight cutoff.*

Film is an analog device, and as such, when it comes to highlights, you have a lot of room to "push" exposure without fear that your going to hit a brick wall after which all additional exposure information is worthless and causes unrecoverable blown highlights no matter your skill in post. Digital sensors, however, DO have a brick wall, and its all too easy to blow out highlights with Canon cameras. Two additional stops of DR, or four times as much sensitivity to light, would greatly increase the amount of tones that could be allocated to highlights, allow smoother and broader highlight "shoulders" when it comes to default tone curves applied by cameras or RAW processors (better simulating film), etc. The benefit is not in what you get strait out of the camera...the benefit is in greater freedom to correct in post, and less need to correct with filtration in-camera because you have more highlight headroom.

Canon seems to have stopped pushing the envelope some 3-4 years ago when they reached about 11.7 stops of maximum DR (thats according to the DXO tests, which measure every level possible from only a few photons to the point where the sensor just begins to blow out highlights.) During the same time period, Nikon and Sony have continued to push the envelope, such that they are now able to utilize almost all of the theoretical headroom possible with 14-bit RAW images. As someone who is pretty heavily invested in Canon equipment, as someone who likes Canon gear and gear options, as someone who is thoroughly invested in my future as a photographer through Canon...I want them to compete and innovate on all fronts. Not just ISO. Not just sensor resolution. Not just lens quality and variety. Not just camera features, AF, fps, etc. Dynamic range matters too, particularly to nature photographers who shoot out in bright daylight frequently, where high contrast scenes and blown highlights (or the potential for them) are common. Its been years since we've seen any real improvement on that front from Canon.

I'm not some wishy-washy whiner who complains about jumping ship to Nikon (or vice versa when the tables are reversed) any time the other brand announces something new and better. I LOVE Canon glass. I LOVE how Canon still innovates in the lens space, with concepts like diffractive optics, built-in teleconverters, specialty lenses like the MP-E 65mm that no other brand has any counterpart for at all. I don't think there is anything better or more versatile than Canon glass in a general sense (although there are the occasional specialized lenses from the likes of Zeiss that certainly do incredible things, such as a lens that can resolve nearly 400lp/mm wide open). I don't want to have to go looking to another brand in a few years because they have pushed the envelope to 15- or 16-bit RAW, and are achieving nearly another two full stops of dynamic range...while Canon simply claims 16-bit RAW, but is still only achieving 12 stops of DR. That would plain and simply suck, and Canon would have less excuse for that than they do now when they claim 14-bit RAW and still only get 11.7 stops of DR. 

I own the 7D, and Canon has thoroughly touted their 14-bit image processing pipeline and 14-bit RAW images it can produce...its rather miffing not to be able to fully utilize all 14 bits on every level...when its clear that its possible because other manufacturers have done it.


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## dtaylor (Feb 26, 2012)

LetTheRightLensIn said:


> Have you ever manipulated a low ISO D3x or D700 file and then gone an manipulated one from Canon? The difference is every bit as real as DxO says it is.



Yes I have. No it is not. Shoot a transmission step wedge with just about any body and compare your results with DxO. Then you'll understand why I laugh at their DR claims.


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## wockawocka (Feb 26, 2012)

I'm very surprised that Canon hasn't gone to 16 bits yet. I've been testing out an Aptus 22 back out and it blows away my 1Ds3 for IQ, but that's all it does.


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## dtaylor (Feb 26, 2012)

Mt Spokane Photography said:


> You still get a tone curve processing in RAW. you have to manulipate it to get a little more DR. Then images tend to look flat. DPR tells you the real world info. Its like a statement of what you get off the showroom floor whan you buy a automobile, its what many, if not most get.



When you process a RAW for maximum DR you don't leave the image flat and walk away. And you don't lose detail if your output device can't handle 10 or 11 stops. You're basically getting all the detail out of the RAW that you can, compressing it down for monitor or print, and restoring the missing contrast and color without blowing back out the shadows and highlights (i.e. LCE, vibrance, saturation...sometimes with masks to protect specific areas).


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## dtaylor (Feb 26, 2012)

thatcherk1 said:


> I think the main point of this thread isn't that we want to shoot the sunset without filters and expect perfect exposure from shadows to the sun itself. I think what people are wanting is Canon to produce a sensor with DR that other manufacturers have already achieved.



LOL! No one else has achieved this. 

See KeithR's posts for dramatic examples of recovery on Canon's 18 MP sensor. Nikon's 16 MP sensor is better than this, but not by much, certainly not by the amount people make it out to be.

Go back to the introduction date of the 7D, the first body with Canon's new 18 MP sensor. I'm pretty sure at that moment Canon had the widest DR crop sensor. Whoever has the newest sensor is likely to have the lowest noise / widest DR until a newer one comes out.


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## Kernuak (Feb 26, 2012)

Tijn said:


> Kernuak said:
> 
> 
> > The human eye is a precision instrument, it will detect meaningful differences if they exist. If it can't detect them, then they are irrelevant, no matter what tests tell you. It's not much use having an extra stop of DR, if your meduim of choice can't show it. I suspect that you'd need an expensive Spectraview type monitor to see any differences.
> ...


I'm not disagreeing that the human eye has much higher DR than any camera, simply that current displays and paper aren't able to match it. If the increases in a sensor's DR isn't replicated in the medium we choose to see the image, then the advantages are limited. HDR compresses the dynamic range, but consumer displays are unable to see the range, until it is tonemapped, which is one of the reasons it looks so unnatural in many cases. Even the use of grad filters can make a scene look unnatural, simply because of the smaller difference between the highlights and shadows (although it isn't compressed in the same way).


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## Kernuak (Feb 26, 2012)

LetTheRightLensIn said:


> Kernuak said:
> 
> 
> > I've said before, that lab tests are pretty meaningless, unless they reflect the real world, after all, as photographers, we are judged by what we achieve, not by what could be theoretically achieved.
> ...


While I've seen the D3, I haven't seen results from those cameras, but have any _real_ comparisons been made? I'm talking about side by side comparisons in the real world, so that as many variables as possible can be ruled out. We can't judge comparisons, if we don't know the conditions at the time of taking. Simple comparisons of unrelated images is simply unscientific and less meaningful than lab tests under artificial conditions (where you can of course control things at least). I'm not saying that there aren't differences, but it's very easy to jump to conclusions. It's very rare, that reviews make direct side by side comparisons, taking near identical shots. Even when you do make comparisons though, Nikon and Canon cameras seem to have different compromises, aiming for more latitude at opposite ends of the spectrum. I've seen too many cases when I was doing research, of papers that put a spin on something that wasn't actually true, when looked at in detail or repeated.



> Flake mentioned the use of HDR and grad filters. As a landscape photographer, I know that even with an extra stop of DR, there is no way that I could capture most scenes without using grad filters, unless I make some compromises. In fact, photography is all about making compromises, that is what sets the greats apart from the merely good.





> But once you are into nearly 3 stops of usably better DR then it does start to make much more a difference in what things you can capture or not.



Three stops is obviously a different matter, but that is a huge jump, in excess of 30%, so is it realistic?



> It's not much use having an extra stop of DR, if your meduim of choice can't show it. I suspect that you'd need an expensive Spectraview type monitor to see any differences.



Not at all. In fact most of them are IPS and don't even have very huge contrast ratio compared to some cheap SPVA screens. But it makes a big difference either way.

And seriously if Canon had 3 usable stops better DR like it did back when, compared to Nikon, would all of you still be finding every excuse in the world why we don't need it and who cares??

Why would anyone, most of all a Canon user, NOT want Canon to fix this up???
I care because I have Canon equipment.
[/quote]
I didn't say that I wouldn't want more DR, quite frankly, any photographer would always be looking for improvements, whatever they are. However, the type of photography I do would probably benefit more from other improvements, such as improved ISO sensitivity (i.e. cleaner). I can already compensate mostly for shortcomings in DR, but noise at higher ISO isn't as easy and if I want to shoot wildlife around dusk, that is a priority for me. Also, some were offering film as having more DR than Canon's sensors, which certainly isn't the case for slide film and is debatable for negative film. If we want improvements, then we have to be realistic in what we compare it too.


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## jrista (Feb 26, 2012)

dtaylor said:


> LetTheRightLensIn said:
> 
> 
> > Have you ever manipulated a low ISO D3x or D700 file and then gone an manipulated one from Canon? The difference is every bit as real as DxO says it is.
> ...



You should take a look at the videos on this page:

http://testcams.com/blog/2011/05/03/nikon-dx-vs-canon-aps-c-dynamic-range/

DXO's results are absolutely real. It boils down to noise floor, and Sony sensors have the lowest floor of any on the market today...by more than two full stops above and beyond what Canon has to offer. The scenario in the link above is not as rare as it may seem. I shoot wildlife and birds a lot, and when it comes to most of the wildlife I shoot...the deer family and canines, they are usually out during golden hour. There isn't much light during that time of day, and the necessity of pushing exposure in post is frequent. I've encountered the read-noise banding issue demonstrated in the videos from the link above frequently...its a detail destroyer like you wouldn't believe, and its impossible to eliminate without significant downscaling. Increasing ISO helps reduce the read noise (for some reason read noise drops as ISO increases with Canon designs), however every stop of ISO increase is also a stop of DR loss, so its a trade-off. 

You can see the difference in read noise levels at sensorgen.info:

*Nikon D7000:*
http://sensorgen.info/NikonD7000.html
Consistent read noise at 3 e-
Mostly linear drop in DR as ISO increases
Max DR at 14 stops (13.9 really), dropping to 12.6, 11.7, 10.7, etc. as ISO increases


*Canon 7D*
http://www.sensorgen.info/CanonEOS_7D.html
Max read noise of 8.6 e- (almost three times that of Nikon)
Average read noise of 3 e- after increasing ISO by three stops
Loss of DR for ISO 100 and ISO 200, ISO 400 is right on the money, ISO 800 loses 1 stop as expected
Max DR at 11.2 stops at ISO 100, 200, and 400

*Canon 5D II*
http://www.sensorgen.info/CanonEOS_5D_MkII.html
Max read noise of 27.8 e- (almost 10 times that of Nikon!!)
Loss of DR through the first four ISO levels, 100-800
Max DR of 11.2 stops at ISO 100, less than expected DR at ISO 200, 400

(NOTE: The 5D II can somewhat handle the higher read noise at low ISO because its pixel capacity is higher than either the D7000 or the 7D because its Full Frame. There are still a lot of complaints about the 5D II's banded read noise though, so its still a visible problem.)



dtaylor said:


> thatcherk1 said:
> 
> 
> > I think the main point of this thread isn't that we want to shoot the sunset without filters and expect perfect exposure from shadows to the sun itself. I think what people are wanting is Canon to produce a sensor with DR that other manufacturers have already achieved.
> ...



Why don't you take a look at the videos in the link above. Sony (and Nikon via Sony sensors) HAVE INDEED achieved better DR and FAR, FAR lower read noise than Canon. The difference is unbelievable. For many photographers, it may not matter, but for those who shoot in lower light, and bleed from their eyes every time they work a photo in post and have to apply an ungodly amount of noise reduction, watching their precious detail disappear as they do so...it matters a LOT.




dtaylor said:


> Go back to the introduction date of the 7D, the first body with Canon's new 18 MP sensor. I'm pretty sure at that moment Canon had the widest DR crop sensor. Whoever has the newest sensor is likely to have the lowest noise / widest DR until a newer one comes out.



Yes, but that was three years ago! Canon hasn't innovated a sensor since (except the 1D X sensor, _which we still have yet to see if it improved DR and read noise or not._ *It could be exactly the same as its always been, without any improvement at all!*) It's been three years since Canon put something other than the same old 18mp sensor in any camera other than their 1D line (and the 1D IV still has the same read-noise banding that all of Canon's other sensors have...search for one of the many 1D IV noise videos on Vimeo for real-world examples.) Post-process shadow recovery is has become an important part of photography for many photographers...not just from the standpoint of fixing a botched exposure, but for those who simply don't have available light, can't or choose not to use flash (for obvious reasons), and need shadow recovery in post to fully realize the shot they took.

It is indeed possible to build a sensor that is capable of using over 99% of the theoretical dynamic range possible with 14-bit data. Sony's done it, they've been doing it for a couple years, and there are many visual examples that prove the point on the net if you care to actually see actual evidence of the difference. For those who know of the issue, and for those to whom it matters, Canon will _really start losing business_ over the next couple of years if they continue to demonstrate an inability or lack of desire to fix the problem in the face of the innovation their competition is showing.


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## LetTheRightLensIn (Feb 26, 2012)

dtaylor said:


> LetTheRightLensIn said:
> 
> 
> > Have you ever manipulated a low ISO D3x or D700 file and then gone an manipulated one from Canon? The difference is every bit as real as DxO says it is.
> ...



You just don't get it.


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## jrista (Feb 26, 2012)

Kernuak said:


> I didn't say that I wouldn't want more DR, quite frankly, any photographer would always be looking for improvements, whatever they are. However, the type of photography I do would probably benefit more from other improvements, such as improved ISO sensitivity (i.e. cleaner). I can already compensate mostly for shortcomings in DR, but noise at higher ISO isn't as easy and if I want to shoot wildlife around dusk, that is a priority for me.



You realize though, that the reason Canon's ISO settings are not that clean is because of their read logic, right? And its also because of their substandard (by todays standards) read logic that they chop off 2.15 stops of DR at ISO 100? The problem is the way they read data off their sensor. If they can fix that properly (i.e. not take some kind of cheap shortcut like they have a couple times in the past), they can fix it all...better high ISO, better low ISO, better dynamic range, etc.



Kernuak said:


> Also, some were offering film as having more DR than Canon's sensors, which certainly isn't the case for slide film and is debatable for negative film. If we want improvements, then we have to be realistic in what we compare it too.



The point about film is not that it has better total dynamic range than a modern digital sensor (although some of the best films do offer a LOT of DR.) The point is that film has much better dynamic range characteristics...with film, its far more difficult to hit a hard cutoff in the highlights than it is with digital sensors. If you know you've over exposed a roll of film or a slide, you can compensate during development with adjusted time or different chemicals, and you have a LOT of freedom to recover highlights. When recovered, you also run a lesser risk of encountering funky color shifts that are so common when recovering highlights with RAW digital images (particularly with Canon, when recovering highlights, yellows and lighter oranges tend to dull and get absorbed into reds, costing you color fidelity.)


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## LetTheRightLensIn (Feb 26, 2012)

Kernuak said:


> LetTheRightLensIn said:
> 
> 
> > Kernuak said:
> ...


I didn't say that I wouldn't want more DR, quite frankly, any photographer would always be looking for improvements, whatever they are. However, the type of photography I do would probably benefit more from other improvements, such as improved ISO sensitivity (i.e. cleaner). I can already compensate mostly for shortcomings in DR, but noise at higher ISO isn't as easy and if I want to shoot wildlife around dusk, that is a priority for me. Also, some were offering film as having more DR than Canon's sensors, which certainly isn't the case for slide film and is debatable for negative film. If we want improvements, then we have to be realistic in what we compare it too.
[/quote]

I have seen a couple pretty impressive side by side comparisons and it was a very real and impressive difference, almost shocking.

Canon cameras are much closer to the SNR middle gray theoretical limits than they are to low ISO DR range limits so you can't be expecting 2-3 stops better SNR middle gray but you could hope for 2-3 stops better usable low ISO DR.


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## jrista (Feb 26, 2012)

LetTheRightLensIn said:


> dtaylor said:
> 
> 
> > LetTheRightLensIn said:
> ...



Wow, he really doesn't. I think we've reached the point where further argument is rather moot...its like talking to that harsh digital highlight cutoff...it ain't listening or moving.


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## torger (Feb 26, 2012)

A problem with DxoMark dynamic range measurements is that they do not show "usable DR". 14 stops measured DR just means that 14 stops down signal is equal to noise, that is how "engineering DR" is measured. But in a real photograph, such noisy information must be black, it is unusable. In fact, those parts of the image that are bright enough to show detail must have pretty good signal-to-noise ratio to look good. So perhaps only 7-8 out of those 14 is usable.

Another problem is that Dxomark does not measure pattern noise, random noise is much more acceptable to the eye than if you see patterns. And this is a weak spot with Canon. So a sensor with random noise with the same DR measurement as say Canon 5D mark II which have some pattern noise will have more dynamic range in practice.

One may argue that Canon sensors are already good enough and that DR problems never occur in normal images. Many photographers have that experience. But that the sensors are actually worse than the competition is easy to prove, just open a raw file from a Canon 7D and from a Nikon D7000 shot at base ISO and push both files 3-4 stops, and watch the noise in the dark parts.

Oh, remember that color negative film, if scanned with HDR on a high quality drum scanner (practically non-existent these days unfortunately), can deliver about 18 stops of dynamic range. There's still improvements to make in digital sensors... People *think* film has poor dynamic range, because they scan it with lousy flatbed scanners, or are used to old analog print workflows when you couldn't really expand the film S-curve. Also slide film while less DR than color negative do have quite good DR, assuming high end scanning equipment.


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## jrista (Feb 26, 2012)

torger said:


> A problem with DxoMark dynamic range measurements is that they do not show "usable DR". 14 stops measured DR just means that 14 stops down signal is equal to noise, that is how "engineering DR" is measured. But in a real photograph, such noisy information must be black, it is unusable. In fact, those parts of the image that are bright enough to show detail must have pretty good signal-to-noise ratio to look good. So perhaps only 7-8 out of those 14 is usable.



Again, I direct everyone to the following example:

http://testcams.com/blog/2011/05/03/nikon-dx-vs-canon-aps-c-dynamic-range/

Based on what you've said, all the "black" in a photograph is unusable because its SNR is too low, and therefor the information is unusable. I think the videos above prove differently. Unusable "blacks" is largely true with Canon sensors, not true in the least with Sony sensors. I think the videos speak for themselves...modern sensors, including canons, offer far more DYNAMIC range than 7-8 stops. Keep in mind, DR and contrast are not the same thing. A final photo may exhibit 7-8 stops of CONTRAST, the measurement of the darkest parts of the scene vs. the lightest parts...but the range of contrast exists within the *full dynamic range* a sensor is capable of. The range of contrast may start lower and end higher, or start higher and end lower. You may have low-key images that only use the darker range of tones offered by a sensor, or high-key images that only use the lighter range of tones offered by a sensor. You may have something that uses mostly the middle tones. Its called *dynamic* range for a reason, and its not the same as contrast. 

Sensors do indeed provide 12-14 stops of dynamic range, and that full range is usable...either to recover a botched exposure, deal with available light issues, etc. The END RESULT of mucking around with a RAW images exposure in post, shifting highlights and shadows...is a photo that probably has around 7-8 stops of tonal range. Print it, and your probably down to 5-6 stops. The end result does not change the nature of the sensor, though...you still have that original 12-14 stops of DR to work with when taking the shot and working it in post.


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## torger (Feb 26, 2012)

jrista said:


> I think the videos speak for themselves...modern sensors, including canons, offer far more DYNAMIC range than 7-8 stops.



May be true, I haven't actually done any subjective tests of how many stops the files actually contains, I have just compared different cameras to eachother and see I sometimes get problems when I push shadows etc. The actual number is not too important, the relative differences are though. What the camera can record in a scene which then can be compressed into a print without visible noise.

The raw files are 14 bit, meaning that 14 stops down the signal is either 0 or 1. At 13 stops down, the range is 0 - 4. Quite coarse quantization. I would be suprised if those last stops are usuable.

The videos are interesting, but I would certainly not use lightroom as some base to check how many stops (the actual number) there are in there, since you can't really trust that program's linearity, so I'd take the "13 or 14 stops of useful dynamic range" with a grain of salt. How much visible noise and dead colors you accept is also subjective, and it also dependent on the picture what works.


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## Marsu42 (Feb 26, 2012)

LetTheRightLensIn said:


> Most DSLR sensors are linear capture so there is no such thing as "at the top of the histogram" and the fact is you can't get out of a 7D image (and yes I have one) wht you can from a D7000 at ISO100.



I won't start an argument over Nikon vs. Canon, but since you say you know about these things: From what I see, a Canon raw image with "highlight tone priority" is not linear - or am I mistaken?


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## torger (Feb 26, 2012)

Marsu42 said:


> I won't start an argument over Nikon vs. Canon, but since you say you know about these things: From what I see, a Canon raw image with "highlight tone priority" is not linear - or am I mistaken?



The raw file content is always linear, since the sensor is linear. How Canon DPP interprets a RAW file with highlight tone priority may be a different story. You need a "dumb" raw processor like dcraw or similar to actually be sure that there's no non-linear trickery added to the RAW data in the conversion.


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## Kernuak (Feb 26, 2012)

jrista said:


> You should take a look at the videos on this page:
> 
> http://testcams.com/blog/2011/05/03/nikon-dx-vs-canon-aps-c-dynamic-range/



A number of things come to mind when watching those videos. He concentrated almost entirely on shadow areas, with very little comment on the highlight areas. DR isn't just about shadow detail, but also highlight detail. Also, it was as much about processing as actual output. Also, they aren't exactly real world images (after all, I don't photograph many beds, with light shining thorugh the window). It was quite disconcerting the way he kept swapping sides, with Canon on the left at the start, then Nikon and back to Canon. Finally, although he didn't show the unprocessed images in detail, the Canon camera was around 1/3rd to 2/3rd stop underexposed in comparison to the Nikon, by my eyes, which will increase noise anyway. No camera (even the same model) will have a guaranteed exposure level for the same ISO, aperture and shutterspeed, due to normal variation. For example, my 7D underexposes by 2/3rd of a stop compared to my 5D MkII, if the same settings are used. To make a true comparison, you would need to compensate for all variations and examine both the highlights and shadows without processing, before trying to extract as much detail as possible. so that you would have before and after results. Without that, testing isn't valid.
It's all pretty moot anyway though, as until anyone sees the results from the 1D X (and the new 5D), nobody can say whether or not the Sony sensors extract more DR, as at the moment, the comparisons are between different sensor generations, with 2+ years difference in release. A more relevant comparison would be between the 5d MkII and D700 or the 7D and D300s. Even the 1D MkIV is now over two years old.


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## Marsu42 (Feb 26, 2012)

torger said:


> Marsu42 said:
> 
> 
> > I won't start an argument over Nikon vs. Canon, but since you say you know about these things: From what I see, a Canon raw image with "highlight tone priority" is not linear - or am I mistaken?
> ...


... fyi: adobe raw and the in-camera preview (which you know of course) interpret the htp raw file just like dpp, but I never tried dcraw.

Which brings me again to my good ol' question about how Canon htp mode works at all. I can see that it raises the iso level, expands the top highlights and in return compresses the shadows - but concerning dr, I don't know how much it's really worth, because it certainly isn't a "mini hdr mode".


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## torger (Feb 26, 2012)

Kernuak said:


> the comparisons are between different sensor generations, with 2+ years difference in release. A more relevant comparison would be between the 5d MkII and D700 or the 7D and D300s. Even the 1D MkIV is now over two years old.



The new G1X sensor which is fairly large, does not look very promising in that regard, but perhaps they've made it deliberatly worse than the 7D sensor to not compete within their own lines.

There's also the thing that Canon simply don't have the Sony Exmor technology. The big difference is that the ADC is on chip. Canon does not have that. Sony Exmor is a minor revolution (for low ISO). What you can expect from Canon is a gradual evolution. You'll certainly see "good enough" performance, but I'll (almost) eat my shorts if it will be world-leading.


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## jrista (Feb 26, 2012)

Kernuak said:


> jrista said:
> 
> 
> > You should take a look at the videos on this page:
> ...



Very true about the need to normalize exposure, and account for differences in samples. I was not trying to use the videos at that link as a way of _objectively measuring_ DR...its just a way to _demonstrate the value_ if having more DR. Even if the 7D exposures were upped by 2/3rds of a stop, its not going to change the horrible read noise, nor the effect it has on the samples the demonstrator was working with. Yes, it was a contrived example, however it was contrived in order to demonstrate. I encounter problems with Canon's read noise without the need to produce a contrived example. In particular, the color noise on any current Canon body is terrible, and what he mentioned about color fidelity is true even when you expose correctly and that proper exposure has dark shadows. Color noise shows through regardless, and you get that unsightly blotchieness all over.



Kernuak said:


> It's all pretty moot anyway though, as until anyone sees the results from the 1D X (and the new 5D), nobody can say whether or not the Sony sensors extract more DR, as at the moment, the comparisons are between different sensor generations, with 2+ years difference in release. A more relevant comparison would be between the 5d MkII and D700 or the 7D and D300s. Even the 1D MkIV is now over two years old.



As far as I know, the first camera with a Sony sensor with improved read noise was released less than a year after the 7D...I'll have to dig around to see if I can find some specifics. Its not just the D7000 sensor that blows Canon sensors out of the water...its Sony sensors released over the last couple years that do. And its very true...we'll have to wait and see how the 1D X and new 5D sensors fare. They may do superbly well, and if they do, I'm a happy camper. If not, well, thats the reason for this thread.


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## Aglet (Feb 26, 2012)

jrista said:


> torger said:
> 
> 
> > A problem with DxoMark dynamic range measurements is that they do not show "usable DR". 14 stops measured DR just means that 14 stops down signal is equal to noise, that is how "engineering DR" is measured. But in a real photograph, such noisy information must be black, it is unusable. In fact, those parts of the image that are bright enough to show detail must have pretty good signal-to-noise ratio to look good. So perhaps only 7-8 out of those 14 is usable.
> ...



Time for me to jump in on this topic. I generally watch from the wings of non-registered users on this forum but this DR topic is my pet peeve with recent Canon bodies too!

I'm an electronics professional by day, love reading all the tech details from various sites but when it comes down to it, let the images speak for themselves.

I don't completely agree with the usability of DXO's sensors tests; they are a good guideline but they seem to not account for the horrendous pattern noise of Canon's recent sensors at low ISO on some bodies.

Also, if you look at the DR curve vs ISO on Canons sensors from way back until now you'll see they're essentially flat before they drop off into the expected slope at higher ISO. The ISO that this occurs has been increasing with newer generations of their sensors, let's call that "improvement."

I was stunned when I saw the curves for Nikon's D7000/5100. THAT, to me, is how that curve should look; you trade sensitivity for DR in a very linear fashion. Canon's curves are not like that, roughly indicating there's a noise floor problem somewhere in their system. That Canon's raw files exhibit more pattern noise at low ISO than at high ISO is baffling but I'll leave analysis of this to sites like clarkvision and others who can delve into details I don't have available

On the practical side...
All the fuss about HDR as a technique should be nearly moot for most scenes if we have a truly decent 14 bit capture. My first Canon body was the 40D. I deliberately held out from going into DSLR until there was more than 12 bits worth of data to work with. The live-view was a massive bonus.

I've done some shots with the 40D where I expose for the highlites and push the shadows in post for an effectively HDR, but realistic-looking shot, based on one properly exposed raw file. They can look great!

With all the hoopla over the 5D2, I was downright unimpressed when I got mine. I had low ISO banding right in the midtones!
In fact, I think my 5D2 and 7D are both turkeys when it comes to all the banding noise in the shadows at low ISO, something my older bodies do not exhibit.
Latest firmware and upgrades to DPP seem to have somewhat mitigated the severity of the problem but when it comes down to it, it seems like I can push the shadows from my 40D a bit more than I can with the 5D2 or 7D.
In fact, I was just thinking about doing a comparison of sorts amongst all the Canon bodies I have access to for exactly this sort of test. I often like to boost shadows in post. The 5D2 and 7D raw files don't often leave me as much to work with as I'd hoped.

I plan to take some shots of "dark" at low ISO and moderate shutter speeds, the sort I'd use in landscape work. I'll then see how far I can push these files in post before the banding noise becomes apparent.
I have access to the following bodies for this test:
350D, 40D, 60D, 7D, 5D2, G11, G12.

It'll take me a bit of time to get this done, got a few projects in the way at the moment but I'll post the results when I do.


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## nightbreath (Feb 26, 2012)

torger said:


> There's also the thing that Canon simply don't have the Sony Exmor technology. The big difference is that the ADC is on chip. Canon does not have that. Sony Exmor is a minor revolution (for low ISO). What you can expect from Canon is a gradual evolution. You'll certainly see "good enough" performance, but I'll (almost) eat my shorts if it will be world-leading.


_The 16 outputs are muxed in 4 ADCs siting on a separate image processor chip Digic 5+_

Taken from Image Sensors World. Isn't that the same as "Exmor technology" you are talking about?


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## LetTheRightLensIn (Feb 26, 2012)

Marsu42 said:


> LetTheRightLensIn said:
> 
> 
> > Most DSLR sensors are linear capture so there is no such thing as "at the top of the histogram" and the fact is you can't get out of a 7D image (and yes I have one) wht you can from a D7000 at ISO100.
> ...



What the sensor is grabbing is still linear, regardless and that is what counts. I'm not sure but I think the RAW is still linear anyway. All it doing is underexposing by one stop but applying a different mid-tone point and different roll-off tone curve for the embedded JPG and hints to the RAW processor to do the same. It's not altering the sensor read in any sort of non-linear way. It's not really any sort of special mode at the hardware level.


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## LetTheRightLensIn (Feb 26, 2012)

Aglet said:


> I don't completely agree with the usability of DXO's sensors tests; they are a good guideline but they seem to not account for the horrendous pattern noise of Canon's recent sensors at low ISO on some bodies.



True and that is why I use both the terms "engineering DR" and "usable DR". When talk "usable DR" the Canon bodies fair worse compared to the Sony exmor sensors than when talking "engineering DR". The 5D2 and 50D lose a noticeable amount of usable performance due to banding. The 1Ds3 and 40D do not lose as much of their engineering DR when comparing it to their usable DR. SOme of the SONY exmor sensors leave even far less.

And it also why all the whining about banding is not just so much nonsense. I've seen people beg for more DR and then whack down all those whining about banding as foolish pixel peepers. I've seen people going on about how some Canon model has 1/3 stop better DR and yet bash down any talk that is has more banding (which ends up making maybe 2/3-1 stop less usable). That doesn't make any sense.



> I was stunned when I saw the curves for Nikon's D7000/5100. THAT, to me, is how that curve should look; you trade sensitivity for DR in a very linear fashion. Canon's curves are not like that, roughly indicating there's a noise floor problem somewhere in their system. That Canon's raw files exhibit more pattern noise at low ISO than at high ISO is baffling but I'll leave analysis of this to sites like clarkvision and others who can delve into details I don't have available
> 
> On the practical side...
> All the fuss about HDR as a technique should be nearly moot for most scenes if we have a truly decent 14 bit capture. My first Canon body was the 40D. I deliberately held out from going into DSLR until there was more than 12 bits worth of data to work with. The live-view was a massive bonus.
> ...



Yes, the 50D and 5D2 generation was one of the worst generations for low iso banding while the 40D and 1Ds3 generation had been one of Canons best generations in terms of that (banding). The 7D is sort of in between when it comes to offset banding but added a new issue, gain banding (which can appear as vertical lines, to various degree in different parts of the frame, and which I also found varied considerably in degree from copy to copy, no Canon sensor I've seen has ever varied so much copy to copy in any way as 7D copies due regarding vertical gain banding, granted my sample sizes are modest, less than a dozen), which can also account for the odd kink in the SNR curve seen on some 7D SNR tests. The 7D also uses an odd dual-green color filter array. The initial RAW converters were not expecting this and the 7D files originally suffered from weird looking mazing artifacts. They were later able to fix this while doing something very ingenious and somehow trading away only a tiny bit of resolution and micro-contrast.




> Latest firmware and upgrades to DPP seem to have somewhat mitigated the severity of the problem but when it comes down to it, it seems like I can push the shadows from my 40D a bit more than I can with the 5D2 or 7D.
> In fact, I was just thinking about doing a comparison of sorts amongst all the Canon bodies I have access to for exactly this sort of test. I often like to boost shadows in post. The 5D2 and 7D raw files don't often leave me as much to work with as I'd hoped.



Very true as soon as I got my 5D2 I noticed it compared to my 40D. As you say the more recent converters do mask it better than the early versions though. Also the 5D2 starts out with more engineering DR than the 40D the so the end result isn't quite as bad relatively speaking as it would be had they started out with the same engineering DR.



> I plan to take some shots of "dark" at low ISO and moderate shutter speeds, the sort I'd use in landscape work. I'll then see how far I can push these files in post before the banding noise becomes apparent.
> I have access to the following bodies for this test:
> 350D, 40D, 60D, 7D, 5D2, G11, G12.
> 
> It'll take me a bit of time to get this done, got a few projects in the way at the moment but I'll post the results when I do.



Some tests with 1D3,1Ds3,5D2,20D,7D,40D,50D were done a few years ago and as I said above the 1Ds3/1D3/40D generation had usable DR closest to engineering DR and the 50D/5D2 the farthest apart.

Some say the 60D has less banding of both types than the 7D.

Only the Sony Exmor sensors have that really super clean read noise. I hope the new 1DX/5DX can at least get close, we will see. I see some signs that hint that they will only close the gap by half, if at all, but hopefully they will close it by 2/3 or even all the way. Hopefully it is possible to do it without patent violation.


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## Kernuak (Feb 27, 2012)

I have to admit, that I haven't run into problems with pattern noise on either my 7D or 5D MKII, but then I probably don't push the ISO high enough and don't push it in PP either. I tend to keep the both at ISO 1600 or below, although I have pushed the 5D MkII to ISO 6400 on a couple of occasions. Also, when I do shoot at higher ISO, the contrast is lower, so the need for DR is reduced, plus I tend to overexpose slightly, shooting for the highlights, but exposing for the shadows, as much as possible. In addition, when I am in those conditions, I'm not looking for detail in the shadows, as it isn't part of the subject generally. Shooting style plays a large role in the amount of noise visible, as does individual cameras, as they are all different. Despite not seeing banding in my current cameras, I did see it in my old 40D at ISO 1600, which was pushing its limits. That was one thing that I liked about the 7D, as not only did it give cleaner images, the quality of the noise was different.


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## LetTheRightLensIn (Feb 27, 2012)

Kernuak said:


> I have to admit, that I haven't run into problems with pattern noise on either my 7D or 5D MKII, but then I probably don't push the ISO high enough and don't push it in PP either. I tend to keep the both at ISO 1600 or below, although I have pushed the 5D MkII to ISO 6400 on a couple of occasions. Also, when I do shoot at higher ISO, the contrast is lower, so the need for DR is reduced, plus I tend to overexpose slightly, shooting for the highlights, but exposing for the shadows, as much as possible. In addition, when I am in those conditions, I'm not looking for detail in the shadows, as it isn't part of the subject generally. Shooting style plays a large role in the amount of noise visible, as does individual cameras, as they are all different. Despite not seeing banding in my current cameras, I did see it in my old 40D at ISO 1600, which was pushing its limits. That was one thing that I liked about the 7D, as not only did it give cleaner images, the quality of the noise was different.



It's not just about high ISO though, if you need to maximize DR then it's an issue at ISO100 too.
7D tends to have less high ISO banding than the 5D2 or 50D.


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## Kernuak (Feb 27, 2012)

LetTheRightLensIn said:


> Kernuak said:
> 
> 
> > I have to admit, that I haven't run into problems with pattern noise on either my 7D or 5D MKII, but then I probably don't push the ISO high enough and don't push it in PP either. I tend to keep the both at ISO 1600 or below, although I have pushed the 5D MkII to ISO 6400 on a couple of occasions. Also, when I do shoot at higher ISO, the contrast is lower, so the need for DR is reduced, plus I tend to overexpose slightly, shooting for the highlights, but exposing for the shadows, as much as possible. In addition, when I am in those conditions, I'm not looking for detail in the shadows, as it isn't part of the subject generally. Shooting style plays a large role in the amount of noise visible, as does individual cameras, as they are all different. Despite not seeing banding in my current cameras, I did see it in my old 40D at ISO 1600, which was pushing its limits. That was one thing that I liked about the 7D, as not only did it give cleaner images, the quality of the noise was different.
> ...


That was one of the things that was touted in reviews when the 7D came out and was one of the reasons, I went for it (I didn't have the 5D MkII at the time), having passed on the 50D as having worse noise characteristics than the 40D. I've never had problems with noise on the 5D MkII at ISO 100, but then I don't have the patience to spend hours processing an image, preferring to try to get it as right as possible in camera.


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## jrista (Feb 28, 2012)

Well, four more days until the official announcement of whatever is replacing the 5D II! The 1D X announcement did not indicate anything about the DR that camera might be capable of, and only specified two additional stops of native high ISO (which, as it turns out, is only actually possible with JPEG, they won't even guarantee a full additional stop for RAW.) Here's to hoping they announce full specs, and at least offer some insight into dynamic range of the 5D II successor.

All I can really say is...*Ima be ubermiffed* if they don't fix their read noise banding (fixed pattern noise), and I'll hold onto my cash until the next camera announcement at end of year. I wonder how the speculative 40+mp Canon sensor will fare...and whether it will improve DR and eliminate read noise or not.


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## wickidwombat (Feb 28, 2012)

How do all the high end medium format digital backs get such good DR? do they read at a higher true bit rate though sampling before the AD converter?


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## torger (Feb 28, 2012)

wickidwombat said:


> How do all the high end medium format digital backs get such good DR? do they read at a higher true bit rate though sampling before the AD converter?



The good DR of medium format is a bit of a myth. They do have 16 bit ADC, but that's meaningless since the noise levels are too high, 14 bit would yield the same result. I've also heard the exposure metering is different from DSLRs, underexposing more so you get more highlight headroom so you can push more in Lightroom which some mistakingly think means that there is more dynamic range.

And then there is what you compare with. If you compare with Canon 5D mark II, yes, there is better dynamic range, because the MF sensors are usually very nice random noise, not patterned noise like on the 5D. But compare with a Sony Exmor sensor and the MF sensor has a little bit less DR. All MF vs DSLR tests I've seen has been with Canon cameras, and they always lose. But they would lose against a Nikon or a Sony with a Sony Exmor sensor too.

Then there is the larger sensor area, there is some DR gain from that since you can gather more photons (less shot noise), but that gain is not very large.

Throughout the years many DSLRs have been released with less than perfect DR, while MF sensors has at least since 2003 had good DR. But that's only on base ISO of course, those CCDs are not good at high ISO. DSLRs have always aimed for more all-around performance including high ISO. Anyway for several years if you have got MF you know that base ISO performance will be great, which has helped established the belief that MF is generally superior, although some DSLRs today mave even have greater DR.


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## jrista (Feb 28, 2012)

I wouldn't be surprised if modern DSLR's, particularly Sony Exmor, had better DR. The pixel densities (pixel pitch) of 60mp FF MF, or 40mp cropped MF, are about the same as a Canon 5D II. From what I understand, the read noise on an MF sensor is just about as bad as on the 5D II, however if they start wiht 16 bits, and lose two stops to read noise, they would still end up with a solid 13-14 stops of DR, which is still about 2 stops better than any Canon sensor. They might lose out just a bit to a Sony Exmor at that point, as Sony consistently pulls off about 13.8 stops of DR.


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## Flake (Feb 28, 2012)

I have a comment, who here has ever managed to test or has seen a test on a sensor from any camera? I've never ever seen a test on a bare sensor, and I truly believe it can't be done in any case. All the tests I've ever seen have been in camera, together with the image processor, and there's the rub, because the Digic, Expeed, Bionz device has at least as much an influence as the sensor if not more. The Bionz device is only 12 bit, the expeed has poor throughput so is switchable to allow 12 / 14 bit, only the Digic is full 14 bit. 

According to one Canon interview (which I can't put my finger on) there's two stops more of DR to be wrung from the image processor than the sensor, before physics says there's a limit.

Cameras are more than sensors (though reading some threads you'd never believe it) Other components have a massive influence on image quality, and it's a mistake to overlook their importance.


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## jrista (Feb 28, 2012)

Flake said:


> According to one Canon interview (which I can't put my finger on) there's two stops more of DR to be wrung from the image processor than the sensor, before physics says there's a limit.



Absolutely...its not exactly the sensor thats the problem, its the ADC. I believe that actually resides in the Digic image processing chip (I'm not 100% certain of that, I've heard conflicting things, and I don't know what patents of Canon's to look at to figure out which is true), rather than in the sensor (at least for current Canon sensors.) If Canon has changed their approach, and put the ADC on-sensor with their new generation of sensors, and even partially taken the Sony Exmor approach of parallelizing ADC, then we could very likely see an improvement. I don't know enough about CMOS electronics to understand exactly why the ADC burns shadow detail and injects so much fixed-pattern noise. There are also other noise sources, such as thermal, which can be introduced by hot components. That would become more of a problem with high speed cameras, however it can be addressed with proper cooling devices, passive or active.



Flake said:


> Cameras are more than sensors (though reading some threads you'd never believe it) Other components have a massive influence on image quality, and it's a mistake to overlook their importance.



Sure, its not just the sensor, its the whole image processing pipeline. I guess I've been using terms loosely, although in the case of Sony Exmor sensors, they definitely pack column-parallel ADC on-chip, and however they designed them, they introduce very little noise (about a third of what the 7D's introduces.) Once the analog signal is converted into digital, its just 1's and 0's, and your not going to see any further introduction of noise...at worst, you might digitally amplify noise (like increasing exposure in post), but with RAW that is obviously not going to happen in-camera.


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## KeithR (Feb 29, 2012)

LetTheRightLensIn said:


> the fact is you can't get out of a 7D image (and yes I have one) wht you can from a D7000 at ISO100.


And it amazes me that people get so frothed up about the fact that _at one ISO setting_ the D7000 can do something that the 7D can't do quite as well...

In over 30,000 actuations, my 7D hasn't _once_ been at 100 ISO; and _at any other ISO_ it compares just fine.

Frankly, I'd expect a near two year newer sensor to be _much, much_ more impressive, in direct comparison to the 7D, than it actually is.

Most importantly of all is the fact that _"properly" exposed_, my 7D has not let me down once. Literally not once. 

People who get all worked up about the "magic" D7000/Pentax K5 sensor seem primarily to do so on the basis that it will allow them to _stuff up_ their exposures, secure in the knowledge that the "ISOless" nature of this sensor will allow them to recover at conversion/in post.

Bugger that - I'll just get it right in camera, thanks..!


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## jrista (Feb 29, 2012)

As someone who also uses my 7D for landscapes, I use ISO 100 as well. I want that maximum DR, and having about two stops chopped off by crappy electronic noise is something I think many of the other landscape photographers who use a 7D is an entirely valid talking point. It should also be noted that for many things, like wildlife and bird photography, the key subject is usually only a part of the frame, and it other parts are blocked or blown it usually doesn't matter as much. When it comes to landscapes (which the 7D is entirely valid for, when you don't have $3000 to spend on a better performing full-frame camera), the whole entire image area matters. 

You need every scrap of DR you can get your hands on. Far more often than not, you have to compromise on image quality by using graduated neutral density filters, which almost always create some kind of undesirable outcome to one degree or another (i.e. black mountain peaks, visible separation between sky and land where land or trees protrude through the flat horizon, etc.) When its obviously possible to NOT lose some two stops of DR to read noise because its been done by the competition, its entirely valid to ask for the same improvement and expect something be done by Canon to provide the same benefit to its customers...especially for the prices they seem to be asking for new gear (which is greater than inflation would indicate, if $3500 for a 5D III body is actually true.)


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## Curmudgeon (Feb 29, 2012)

It's too bad the swamping of the servers sort of dried up this thread, although maybe the subject has now been covered in reasonable depth. I've been looking back over the posts, and I have to say this is one of the most informative and civilized Internet discussions I've ever encountered. 

We all know about the excesses and personality aberrations that online forums seem to encourage, but this forum in general and this thread in particular strike me as an example of the positive possibilities of the Internet. I posted several questions myself over the course of the thread and within 24 hours had incisive answers from knowledgeable respondents. You can't get that off Wikipedia unless you already know a lot about the subject you're querying. Have there been disagreements between posters? Of course. Knowledgeable people frequently disagree on specific points. But for the most part the discussion has been carried out without giving or taking the kind of personal offense that has led me to shy away from participating in these discussions.

As a film era fogey trying to expand my grasp of what has become an ever more technical medium, this is exactly what I hoped to get when I registered for this forum. Not only have I increased my understanding of the subject in an academic sense, but I've acquired some practical, useful knowedge about what I can reasonably expect from the 5D3. When (if) it arrives I'll have a better idea of whether it's time for a new body or in the short term my precious photographic dollars would be better spent on, say, a full lash-up of Lee GNDs. (I've noticed that a lot of people get a little sheepish about the geekiness of participating in these discussions, and I know, I know, it's the photographer not the equipment, but, ... it seems to me that the medium has indeed become so technical--and expensive--that making informed purchases plays at least a modest part in improving the quality of one's photographic output.)

In any event, I'd like to offer a little word of appreciation to jrista, dtaylor, LetTheRightLensIn, Mt Spokane, mkln, Kernuak, Tijn, Flake, Flake, torger, Marsu42 and all the others who made this a stimulating and useful discussion. And Hello to Aglet, another noobie who got sucked off the forum sidelines and into the fray by the issue of dynamic range in Canon equipment.

And while I'm at it, amen to jrista's previous post:

"You need every scrap of DR you can get your hands on. Far more often than not, you have to compromise on image quality by using graduated neutral density filters, which almost always create some kind of undesirable outcome to one degree or another (i.e. black mountain peaks, visible separation between sky and land where land or trees protrude through the flat horizon, etc.) When its obviously possible to NOT lose some two stops of DR to read noise because its been done by the competition, its entirely valid to ask for the same improvement and expect something be done by Canon to provide the same benefit to its customers...especially for the prices they seem to be asking for new gear (which is greater than inflation would indicate, if $3500 for a 5D III body is actually true.)"

There are three significant problems with NDs.

1) As jrista points out, it's hard not to leave obvious traces of them in the photograph--especially if, like me, mountain scenery is a favorite subject.

2) A good set is considerable added weight, especially if you're an aging backpacker who's already made the concession to artistic integrity of schlepping a full frame DSLR and several lens.

3) Shooting landscapes is not like covering the sidelines of the NBA or NFL, but it's amazing how often the best shots involve serendipity and "shooting from the hip." One day 40 years ago I waited until the rain stopped to take out the trash--and walked into what remains the most spectacular sunset I've ever seen. Cloud textures in infinite variety and god rays up the ying yang. I dropped the can, ran inside and grabbed my tripod and old Mamiya SLR and fired off the half roll of film in the camera. I'd never heard of a neutral density filter, but I got the shot. The scene was gone in two minutes. If I'd been fumbling around mounting, testing and aligning NDs on my 5D2 I'd have gotten a well-exposed shot of the afterglow.


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## Kernuak (Feb 29, 2012)

The 7D isn't really suited to landscape work, for more reasons than DR, it can do it, but it doesn't produce the best results. Just like the 5D MkII and wildlife, it can do it, but it isn't its forte. I orignally got my 7D to replace the 40D, but I kept the 40D, following an instance where I missed a shot through only having one body. The plan was to use it for landscape and wildlife, just like I had with the 40D. I had seen some deficiencies with the 40D for landscapes, but as soon as I got the 7D, everything was magnified. L zooms start to look soft on crop cameras due to diffraction and of course, the diffraction limited aperture on the 7D is wider than on the 40D due to the pixel density and interference due to Airey discs. This coupled with the higher resolution show up the softer images more, particularly in the corners (even though the worst performing parts of a lens are cropped out by the sensor). According to DXO, the 7D has more DR than the 5D MkII, but I don't actually find to usable, particularly before one of the early firmware updates. You tend to get more colour casts on the 7D and some of my early shots were distinctly pink in the highlight areas.
I much prefer to get it as right as possible in camera and that is why I choose to use grad filters. Many of the landscapes I shoot have upwards of 5 stops difference between the foreground and sky, so even with a 3 stop improvement in DR, I won't be selling off my Lee grad filters any time soon.


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## jrista (Feb 29, 2012)

Kernuak said:


> The 7D isn't really suited to landscape work, for more reasons than DR, it can do it, but it doesn't produce the best results.



Hmm, really? I...I would have never known...

(Just a random sampling. Take a skilled photographer, the 10-22 EF-S, and maybe a few GND filters, and the 7D can do wonders!)
http://500px.com/photo/1157203
http://500px.com/photo/3718508
http://500px.com/photo/3131439
http://500px.com/photo/1929326
http://500px.com/photo/3981585

Sadly, you can clearly tell most of those have used a GND filter or two. But thats exactly my point about DR. 



Kernuak said:


> Just like the 5D MkII and wildlife, it can do it, but it isn't its forte. I orignally got my 7D to replace the 40D, but I kept the 40D, following an instance where I missed a shot through only having one body. The plan was to use it for landscape and wildlife, just like I had with the 40D. I had seen some deficiencies with the 40D for landscapes, but as soon as I got the 7D, everything was magnified.



The reason the 5D II isn't great for wildlife is because its limited by AF. It doesn't really have better DR than the 7D though (I think the difference between the two is a small fraction of a stop), and at ISO 100, the two cameras are little different from each other (except for the fact that the 5D II exhibits less noise and has a larger frame.) Conversely, the 7D HAS a highly capable AF system, but that doesn't preclude it from being used for other purposes, like landscapes. If the 5D III gets a nice AF system, it will be every bit as capable for wildlife as for landscapes, limited against the 7D only in the aspect of reach.



Kernuak said:


> L zooms start to look soft on crop cameras due to diffraction and of course, the diffraction limited aperture on the 7D is wider than on the 40D due to the pixel density and interference due to Airey discs. This coupled with the higher resolution show up the softer images more, particularly in the corners (even though the worst performing parts of a lens are cropped out by the sensor).



I think this is an area where most people misunderstand diffraction. On the 7D, vs. the 40D, diffraction only *sets in* sooner...simply because the 7D is recording at a higher resolution. The 7D is recording more information at a finer degree, and the only reason...at 100% crop...it looks "worse" than the 40D is simply because the 40D is incapable of capturing enough detail for an even comparison. Normalize the image size with the 40D, and the 7D will always win. You can NEVER get WORSE IQ with more resolution...you can only approach a point where you get diminishing returns for significant increases in cost (and image files that are so huge and contain so many pixels that you don't need all the extra data anyway, even IF your upscaling.) Scale any pair of images from the 7D and 40D down to say 900 pixels long edge, and all that "softness" you see when pixel peeping at 100% will become a total non-issue. Print at 8x10 or 13x19, and the problems you perceive at 100% will also cease to be an issue (well, probably less than 13x19, since the 40D can't actually achieve that natively...maybe 11x16.) You can't compare IQ when viewing a 100%, because you are literally comparing apples to oranges. 



Kernuak said:


> According to DXO, the 7D has more DR than the 5D MkII, but I don't actually find to usable, particularly before one of the early firmware updates. You tend to get more colour casts on the 7D and some of my early shots were distinctly pink in the highlight areas.
> I much prefer to get it as right as possible in camera and that is why I choose to use grad filters. Many of the landscapes I shoot have upwards of 5 stops difference between the foreground and sky, so even with a 3 stop improvement in DR, I won't be selling off my Lee grad filters any time soon.



Sure, I'm an advocate of _get it right in-camera_, too. And "usable DR" is a tough thing to nail down, so experiences differ on that front. I usually have to use my Lee .6 GND, sometimes the .9, and its only in extreme cases where I need to correct more than about 3 stops of contrast different to capture a landscape the way I want to (I don't usually want to capture an unlimited amount of detail in the shadows, I'm happy leaving them dark most of the time.) I think my assertions here about DR play MORE to the whole "get it right in camera" crowd than anyone else though. With more DR, you have more room within which to work...in camera...out in the field, than if you have less DR. With more DR, you have to spend less time fiddling around with physical filtration to get a good shot, meaning that when that moment...that extremely SHORT moment...hits, when light and shadow is absolutely perfect, and your simply agape in awe, you have more time to think about composition, exposure, etc. and get that superb shot...WITHOUT any funky shading because of the need to use graduated filters.


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## jrista (Feb 29, 2012)

Curmudgeon said:


> It's too bad the swamping of the servers sort of dried up this thread, although maybe the subject has now been covered in reasonable depth. I've been looking back over the posts, and I have to say this is one of the most informative and civilized Internet discussions I've ever encountered.
> 
> We all know about the excesses and personality aberrations that online forums seem to encourage, but this forum in general and this thread in particular strike me as an example of the positive possibilities of the Internet. I posted several questions myself over the course of the thread and within 24 hours had incisive answers from knowledgeable respondents. You can't get that off Wikipedia unless you already know a lot about the subject you're querying. Have there been disagreements between posters? Of course. Knowledgeable people frequently disagree on specific points. But for the most part the discussion has been carried out without giving or taking the kind of personal offense that has led me to shy away from participating in these discussions.
> 
> ...



Certainly! I always enjoy a good debate, especially when they don't degrade into uselessness like so many things on the net.


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## Kernuak (Feb 29, 2012)

jrista said:


> Kernuak said:
> 
> 
> > The 7D isn't really suited to landscape work, for more reasons than DR, it can do it, but it doesn't produce the best results.
> ...



You don't need a 10-22 to get good results, in fact for many of the landscapes around here, that would be far too wide. The difference is, when you're using longer focal lengths, you need narrower apertures, so diffraction becomes more of an issue. While they're good images, they're too heavily processed for my tastes. That's probably the main difference between your experience and mine, as the more processing work, the greater the chance that noise starts to show. Also, I judge based on 50%, as that is more representative of what is visible in an average print and may have a greater tolerance for noise in an image anyway.



> Kernuak said:
> 
> 
> > Just like the 5D MkII and wildlife, it can do it, but it isn't its forte. I orignally got my 7D to replace the 40D, but I kept the 40D, following an instance where I missed a shot through only having one body. The plan was to use it for landscape and wildlife, just like I had with the 40D. I had seen some deficiencies with the 40D for landscapes, but as soon as I got the 7D, everything was magnified.
> ...



Precisely. However, when it gets dark, I find the AF on the 5D MkII more reliable...as long as I use the centre point.



> It doesn't really have better DR than the 7D though (I think the difference between the two is a small fraction of a stop).



I didn't say that the 5D has more DR than the 7D (DXO suggests the opposite), but in terms of what [i'I[/i] find usable, it is better, in fact, the cut off at both ends is slightly different between the two. It also has a different tonality, that I prefer.



> Conversely, the 7D HAS a highly capable AF system, but that doesn't preclude it from being used for other purposes, like landscapes. If the 5D III gets a nice AF system, it will be every bit as capable for wildlife as for landscapes, limited against the 7D only in the aspect of reach.



Likewise, I didn't say that it was preculded from other purposes, on the contrary, I used it for landscapes for around 6+ months before I got the 5D.



Kernuak said:


> L zooms start to look soft on crop cameras due to diffraction and of course, the diffraction limited aperture on the 7D is wider than on the 40D due to the pixel density and interference due to Airey discs. This coupled with the higher resolution show up the softer images more, particularly in the corners (even though the worst performing parts of a lens are cropped out by the sensor).



I think this is an area where most people misunderstand diffraction. On the 7D, vs. the 40D, diffraction only *sets in* sooner...simply because the 7D is recording at a higher resolution. The 7D is recording more information at a finer degree, and the only reason...at 100% crop...it looks "worse" than the 40D is simply because the 40D is incapable of capturing enough detail for an even comparison. Normalize the image size with the 40D, and the 7D will always win. You can NEVER get WORSE IQ with more resolution...you can only approach a point where you get diminishing returns for significant increases in cost (and image files that are so huge and contain so many pixels that you don't need all the extra data anyway, even IF your upscaling.) Scale any pair of images from the 7D and 40D down to say 900 pixels long edge, and all that "softness" you see when pixel peeping at 100% will become a total non-issue. Print at 8x10 or 13x19, and the problems you perceive at 100% will also cease to be an issue (well, probably less than 13x19, since the 40D can't actually achieve that natively...maybe 11x16.) You can't compare IQ when viewing a 100%, because you are literally comparing apples to oranges. [/quote]


If that was the only reason, then why is DLA quoted in terms of pixel size? I agree, that a large part of the increased softness is due to looking at a smaller area and more detail, but there are also relationships between the pixel:Airy disk size ratio. When using the 17-40 and 24-105 though, I certainly noticed soft corners (although I also see it on the 5D because of the lack of sweet spot effect from crop sensors).



> Kernuak said:
> 
> 
> > According to DXO, the 7D has more DR than the 5D MkII, but I don't actually find it usable, particularly before one of the early firmware updates. You tend to get more colour casts on the 7D and some of my early shots were distinctly pink in the highlight areas.
> ...


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## jrista (Feb 29, 2012)

Kernuak said:


> If that was the only reason, then why is DLA quoted in terms of pixel size? I agree, that a large part of the increased softness is due to looking at a smaller area and more detail, but there are also relationships between the pixel:Airy disk size ratio. When using the 17-40 and 24-105 though, I certainly noticed soft corners (although I also see it on the 5D because of the lack of sweet spot effect from crop sensors).



The misconception is in the (incorrect) idea that once the airy disk has grown larger than about a 2x2 pixel area, IQ _DROPS_. That is ABSOLUTELY NOT the case. If you take a camera with a pixel pitch of 6um, and another camera with a pixel pitch of 3um. You can fit four times as many 3um pixels into the total area of a single 6um pixel. Diffraction will set in at around f/11 for the 6um camera, where as it will probably set in around f/6 for the 3um camera. *Note the pixel sizes there*...at f/6, the airy disk has grown large enough to _become apparent_. The 3um sensor is now *diffraction limited*, in that as you continue to stop down the aperture, diffraction will interfere more and more with detail. Lets say you stop down to f/8. Well, your 3um sensor is recording some of the effects of diffraction...they are minor, and your still capturing a lot of detail, but diffraction is having an effect. The 6um sensor, however, isn't even experiencing the effects of diffraction yet. Its still capturing LESS detail, despite the fact that the 3um sensor is now a full stop beyond its initial DLA. Now lets stop down to f/22. Diffraction will visibly affect image quality now...softness will be prevalent. The images from both sensors now are roughly the same...however the 3um sensor is still going to produce a slightly better result, since its recording the image at a finer level than the 6um sensor. Think about pixellation of an image...if you pixellate at 6x6 pixel and 3x3 pixel squares, even if you blur the image, the 3x3 pixellated image is always going to exhibit more detail. 

You can't get *worse* quality from a higher resolution sensor as you stop down to progressively smaller apertures. You only approach a normal baseline, wherein all images from any camera of any resolution are pretty much the same.


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## Circles (Mar 1, 2012)

Precisely. However, when it gets dark, I find the AF on the 5D MkII more reliable...as long as I use the centre point


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## RedEye (Mar 1, 2012)

jrista said:


> Kernuak said:
> 
> 
> > If that was the only reason, then why is DLA quoted in terms of pixel size? I agree, that a large part of the increased softness is due to looking at a smaller area and more detail, but there are also relationships between the pixel:Airy disk size ratio. When using the 17-40 and 24-105 though, I certainly noticed soft corners (although I also see it on the 5D because of the lack of sweet spot effect from crop sensors).
> ...



Thank you for the excellent explanation!
+1


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## jrista (Mar 1, 2012)

RedEye said:


> Thank you for the excellent explanation!
> +1



Glad to be of service. (And I'm glad that was useful to someone...usually when I post something like that its the end of the thread.


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## Flake (Mar 1, 2012)

"You need every scrap of DR you can get your hands on."

Well if you really do need every scrap here's something to consider.

The full exposure of a DSLR camera is acheived when just one of the three RGB channels reaches the 255 value (or close to it), so it makes sense to attept to try to balance the three colours which will give a higher DR. In situations where the white balance is not optimum, a return to using the old correction filters will help, tungsten having more red channel and fluoresecent having more blue. Removing these colour casts means that the light reaching the sensor is more 'balanced' there is no colour peak in one of the channels & therefore more headroom.


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## jrista (Mar 2, 2012)

Flake said:


> "You need every scrap of DR you can get your hands on."
> 
> Well if you really do need every scrap here's something to consider.
> 
> The full exposure of a DSLR camera is acheived when just one of the three RGB channels reaches the 255 value (or close to it), so it makes sense to attept to try to balance the three colours which will give a higher DR. In situations where the white balance is not optimum, a return to using the old correction filters will help, tungsten having more red channel and fluoresecent having more blue. Removing these colour casts means that the light reaching the sensor is more 'balanced' there is no colour peak in one of the channels & therefore more headroom.



I guess thats an option. Some concerns with that would be the effect of an additional filter element in front of the lens...greater chance for flaring, reduction in contrast or sharpness due to the quality of the filter (which can be very high, but very rarely as high as the glass in the lens itself), etc. With 35mm film, resolution was generally not as high as it is today (with a few exceptions), so the impact of a filter on resolution, vs. the ability to correct white, was not a big deal. With incredibly high resolution sensors today, the quality of all the optics in front of them matters more and more.


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