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Author Topic: Nikon D7000 Dynamic Range  (Read 111524 times)

ErikKaffehr

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Re: Nikon D7000 Dynamic Range
« Reply #40 on: November 17, 2010, 01:03:56 AM »

Hi,

I made some comparisons between APS-C and full frame in A2-prints. The outcome was interesting:

I one case I could not tell the prints apart. In several other cases the difference was small but I could tell the images apart easily at some distance.

The differences in the prints were much smaller than the difference in files.

---

I also made an experiment with downloaded images shot with different cameras. This was a studio setting, a portrait shot with a lot of different cameras.

So I downloaded an image from D3X and Hasselblad H#D50. Comparing the images at actual pixels it was noted that the Hasselblad image had much more resolution in a very small area than the Nikon D3X. The reason of that area being so small was depth of focus. I made an A2 print of both images and showed to two friends who both worked previously at professional labs. Both said that the images were close, one found the Nikon image sharper and the other one found the Hassy image sharper. Myself new from pixel peeping where to look...

That said, the Nikon image was better! This is one of the issues shooting portrait models in studio. Depth of field is very short and the subject is changing all the time.

To sum up:

In my view, very good A2 prints can be done from 12 MP APS-C images. The file from the larger sensor will be significantly better but the difference in the prints will be smaller than what would be expected from pixel peeping the files.

Best regards
Erik Kaffehr


Are you really sure?
Did you print already an A2 side by side?

We will throw away all our stuff to get this miracle!

Many thanks for your information.

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Ray

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Re: Nikon D7000 Dynamic Range
« Reply #41 on: November 17, 2010, 02:05:27 AM »


What BJL and I say is that recent wins in the dynamic range may be more related to reduction in readout noise. But at low exposures shot noise will dominate.


Erik,
I'm not clear on this. I presume by 'low exposure' you mean fast exposure, resulting in a small amount of light reaching the sensor. In such circumstances, shot noise will be a greater proportion of the signal (but lower in absolute terms than a longer exposure).

Read noise will also be greater as a proprtion of the signal, so at high ISOs noise is a significant problem, both read noise and shot noise.

What has tended to happen with modern DSLRs, is that the underexposed image at any ISO higher than base, is amplified in its analog state so that it emulates in signal strength the correctly exposed image at base ISO.

Now the amplified signal also amplifies any noise currently present, as well as introducing amplifier noise. That's unavoidable. But the benefit lies in the further signal processing, up-chain (in-camera), before the signal is eventaully written to the memory card.

Such further noise introduced by such processing (A/D conversion, dark frame subtraction, whatever), becomes less proportionally than it otherwise would be.

That's my understanding. Correct me if I'm wrong.

What appears to have happened with the current D7000 and K-5, is that the analog boost to the signal occurs at base ISO to create a larger signal than results in other cameras at base ISO.

As a consequence, the high ISO of the D7000 is no better than competing models, such as the D60 or 7D. But the low ISO performance actually is better by a noticeable margin.

This is no doubt an oversimplified interpretation. Perhaps Emil Martinec could clarify.





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dimapant

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Re: Nikon D7000 Dynamic Range
« Reply #42 on: November 17, 2010, 07:54:53 AM »

Sir,
now is clear and I thank you again for your accurate information.

Best regards

I am new on the forum, sorry: this message is for RAY, for his kind explanation on Dynamic range in answer to my question
« Last Edit: November 17, 2010, 08:06:35 AM by dimapant »
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dimapant

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Re: Nikon D7000 Dynamic Range
« Reply #43 on: November 17, 2010, 08:04:22 AM »

Sir,
many thanks also to you for your kind comparison.

I had some doubts about the capability of a Dx or APC forrmat to provide good performances on large (for me) print like A2 format.

I have to revise my opinions and try, as a small camera is quite flexible from the operative point of view, and now is becoming very attractive.

Best regards

Sorry for my bad management of the answers: this message is for Mr EriKKaffehr, for providing me explanation on A2 prints by APC format
« Last Edit: November 17, 2010, 08:09:33 AM by dimapant »
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FranciscoDisilvestro

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Re: Nikon D7000 Dynamic Range
« Reply #44 on: November 17, 2010, 09:41:33 AM »

If read noise is so low that even at base ISO the dynamic range is limited by shot noise, then ISO could well be a metadata if you shoot RAW. ISO variation as Analog amplification of the signal will not have any benefit. Even out of Camera Jpegs could be processed according to this metadata, as in the case of White Balance

Ray

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Re: Nikon D7000 Dynamic Range
« Reply #45 on: November 17, 2010, 07:46:10 PM »

I notice at DPreview there are a few example images showing noise and detail differences in 'raised' shadows, comparing identical scenes taken with the 60D and D7000. I'm not sure how reliable such examples are.

However, the magnitude of such differences seem to be similar to the differences clearly apparent in the cropped sections of my sunset shot of St Isaac's in St Petersburg, comparing exposures with the 50D that differ by 2.67 stops.

There's a clear implication here that the higher DR of the D7000 claimed by DXO really does translate to a pratical increase in useful dynamic range, compared with Canon DSLRs, notwithstanding claims that such increased performance is already limited by shot noise.

This really is a mixed blessing for me. I'd prefer it to be true that any DR advantage of the D7000 is a fiction as a result of shot noise limitations. I could then quite happily buy a 60D without the feeling that maybe I was depriving myself of some 'occasionally desired' increase in DR capability. I have only one Nikkor lens, the 14-24/2.8.

Will someone please show me some comparison shots of a scene of extremely high SBR, taken with flawless technique, using the D7000 and D60, demonstrating that the theoretical DR advantage of the D7000 is of no practical value.  ;D
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ErikKaffehr

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Re: Nikon D7000 Dynamic Range
« Reply #46 on: November 18, 2010, 01:21:39 AM »

Hi,

I wanted to post you these links but "PBase" was unavailable yesterday:

Here are crops from A900 (FF) and A700 (DX)
http://www.pbase.com/ekr/image/107619976/original

And here are scanned crops from approximately A2 size prints:
http://www.pbase.com/ekr/image/107823207/original

Printing was done from Lightroom on Epson SP3800, at 480 PPI and normal sharpening for glossy. The prints were scanned at 300 PPI on a cheap Canon scanner.

I had a couple of friends check the images, and no one could tell them apart. That said I made similar tests with other images and I could clearly tell A2 prints apart.

I mostly use full frame, and regard it as a good buy. Image quality is certainly better with larger sensor, but APS-C size may be good enough.

The processing pipeline is very important. I'd say that correct capture and output sharpening has a great significance for print quality.

Best regards
Erik


Sir,
many thanks also to you for your kind comparison.

I had some doubts about the capability of a Dx or APC forrmat to provide good performances on large (for me) print like A2 format.

I have to revise my opinions and try, as a small camera is quite flexible from the operative point of view, and now is becoming very attractive.

Best regards

Sorry for my bad management of the answers: this message is for Mr EriKKaffehr, for providing me explanation on A2 prints by APC format
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dimapant

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Re: Nikon D7000 Dynamic Range
« Reply #47 on: November 18, 2010, 06:03:55 AM »

Hi,

I wanted to post you these links but "PBase" was unavailable yesterday:

Here are crops from A900 (FF) and A700 (DX)
http://www.pbase.com/ekr/image/107619976/original

And here are scanned crops from approximately A2 size prints:
http://www.pbase.com/ekr/image/107823207/original

Printing was done from Lightroom on Epson SP3800, at 480 PPI and normal sharpening for glossy. The prints were scanned at 300 PPI on a cheap Canon scanner.

I had a couple of friends check the images, and no one could tell them apart. That said I made similar tests with other images and I could clearly tell A2 prints apart.

I mostly use full frame, and regard it as a good buy. Image quality is certainly better with larger sensor, but APS-C size may be good enough.

The processing pipeline is very important. I'd say that correct capture and output sharpening has a great significance for print quality.

Best regards
Erik



Impressive!
They are the same, you cannot tell which one is coming from.
Good News!

Many thanks and best regards.

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BJL

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where and how to improve Dynamic Range
« Reply #48 on: November 18, 2010, 06:29:09 PM »

... recent wins in the dynamic range may be more related to reduction in readout noise. But at low exposures shot noise will dominate. Shot noise is simple photon statistics, nothing chip designers can do anything about.
Agreed. For one thing, "not enough DR" is often said when the problem is not enough highlight headroom above the midtone exposure level, and that is all about (a) giving the sensor enough exposure to gather enough photons from the midtones and shadow regions with significant detail to overcome shot noise, and (b) the sensor then being able to handle the high photon counts in the highlights.
A standard recommended by Kodak is that a 40:1 SNR in the mid-tones gives excellent IQ while 10:1 is minimally acceptable, and my experience indicates that somewhere around 20:1 is the threshold for "quite good". At all these levels, shot noise dominate over the 3e- or less read noise of modern DSLR CMOS sensors (and even more so in modern compacts, whose sensors have even lower read noise in electron counts) because 10:1 needs at least 100e- of signal and so 10e- RMS shot noise, and 40:1 requires at least 1600e- signal and 40e- RMS of shot noise. Normal highlight handling only needs about 3 stops or well capacity a bit under 10 times midtone signal so even 40:1 SNR only needs a 6,000e- well capacity, but if one asks for five stops (following the only zone system idea of zone 5 for midtones, zone 10 or above max), one needs to be able to handle 2^5=32 times the midtone signal, or 51,200e-. [Aside: dithering or downsampling can reproduce this from more, smaller photosites so that for example twice as many pixels as needed for resolution each with half that target well capacity, or 25,600, would work about as well for this.]

That 40:1 SNR and 5-stops are rather strict requirements, as appropriate for people who worry that the 12 stop DR of modern DMF sensors is not enough. A mere four stops is probably a good amount of head-room most of the time, and my experience suggests that around 500e- in the midtones, giving a bit over 20:1 SNR, is enough to look quite good so long as one is not messing with tone curves to lighten shadow regions substantially. For example, on the D7000, exposure index of ISO 1600 gives about 400e- in the midtones, I think). If so, a well capacity of about 2^4*500=8000e- could be enough "for most purposes of most photographers", as far as highlight handling with normal degree of shadow handling needed.

Maybe it is a pity that the only sensor technology that tried to expand highlight headroom by effectively increasing maximum photon count far beyond the normal limits of well size, Fujifilm's SuperCCD SR, has failed in the DSLR marketplace. Or maybe that just shows that some of us are worrying about highlight headroom and DR way too much, and should get back to the time-honored basics of photographic discussions: arguing about lenses!
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bjanes

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Re: where and how to improve Dynamic Range
« Reply #49 on: November 18, 2010, 09:24:32 PM »

Normal highlight handling only needs about 3 stops or well capacity a bit under 10 times midtone signal so even 40:1 SNR only needs a 6,000e- well capacity, but if one asks for five stops (following the only zone system idea of zone 5 for midtones, zone 10 or above max), one needs to be able to handle 2^5=32 times the midtone signal, or 51,200e-

A nice analysis, but one problem with applying the zone system to digital photography is that there is only a 2.5 stop difference between mid-gray (18% sensor saturation) and highlight saturation, not the 5 stops that one would expect. Placing the highlights 0.5 EV below saturation gives 3 EV headroom above middle gray, which would then correspond to 12.7% saturation. This corresponds to the ISO saturation spec for digital sensor rating. IMHO, allowing 5 stops is not proper ETTR exposure.

BTW, what do you regard as the the minimum SNR for acceptable shadow detail in determining photographic DR?

Regards,

Bill
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ejmartin

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Re: Nikon D7000 Dynamic Range
« Reply #50 on: November 18, 2010, 09:33:56 PM »

Discussions of SNR should also take into account that SNR varies with spatial frequency.  SNR of 40 at 1000 lph is quite different from SNR=40 at 4000 lph.
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emil

BJL

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Re: Nikon D7000 Dynamic Range
« Reply #51 on: November 18, 2010, 10:48:04 PM »

A nice analysis, but one problem with applying the zone system to digital photography is that there is only a 2.5 stop difference between mid-gray (18% sensor saturation) and highlight saturation, not the 5 stops that one would expect.
A clarification: I know that there is only 2.5 stops from 18% reflectance to 100%, but was thinking of extreme cases where metered mid-tones are far lower, like having shadows on the main subject that one want to print at middle gray but something brightly sunlit elsewhere in the scene. The base ISO standard allows a bit over three stops above mid-tones, a luminosity factor of 170/18 IIRC (to allow for a main subject darker than 18% reflectance, or somewhat shadowed?), but some people complaining about blown highlights clearly want more at times. My five stops was a rather arbitrary value chosen to be generous to that wish, for cases where exposing to put the highlights just below saturation (ETTR?) places a dimly lit main subject well below 18% of maximum subject brightness. If in that situation someone still wants an excellent 40:1 SNR on the shadowy main subject, big well capacities are needed --- though I suspect that this need is far rarer in real life than in gear-head forum discussions. (I personally avoid having the main subject more than four stops below highlights that cannot be allowed to "white-out", by adjusting composition, because I have never succeeded in getting nice prints in that situation.)
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Ray

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Re: where and how to improve Dynamic Range
« Reply #52 on: November 18, 2010, 11:22:46 PM »

Agreed. For one thing, "not enough DR" is often said when the problem is not enough highlight headroom above the midtone exposure level, and that is all about (a) giving the sensor enough exposure to gather enough photons from the midtones and shadow regions with significant detail to overcome shot noise, and (b) the sensor then being able to handle the high photon counts in the highlights.
A standard recommended by Kodak is that a 40:1 SNR in the mid-tones gives excellent IQ while 10:1 is minimally acceptable, and my experience indicates that somewhere around 20:1 is the threshold for "quite good". At all these levels, shot noise dominate over the 3e- or less read noise of modern DSLR CMOS sensors (and even more so in modern compacts, whose sensors have even lower read noise in electron counts) because 10:1 needs at least 100e- of signal and so 10e- RMS shot noise, and 40:1 requires at least 1600e- signal and 40e- RMS of shot noise. Normal highlight handling only needs about 3 stops or well capacity a bit under 10 times midtone signal so even 40:1 SNR only needs a 6,000e- well capacity, but if one asks for five stops (following the only zone system idea of zone 5 for midtones, zone 10 or above max), one needs to be able to handle 2^5=32 times the midtone signal, or 51,200e-. [Aside: dithering or downsampling can reproduce this from more, smaller photosites so that for example twice as many pixels as needed for resolution each with half that target well capacity, or 25,600, would work about as well for this.]

That 40:1 SNR and 5-stops are rather strict requirements, as appropriate for people who worry that the 12 stop DR of modern DMF sensors is not enough. A mere four stops is probably a good amount of head-room most of the time, and my experience suggests that around 500e- in the midtones, giving a bit over 20:1 SNR, is enough to look quite good so long as one is not messing with tone curves to lighten shadow regions substantially. For example, on the D7000, exposure index of ISO 1600 gives about 400e- in the midtones, I think). If so, a well capacity of about 2^4*500=8000e- could be enough "for most purposes of most photographers", as far as highlight handling with normal degree of shadow handling needed.

Maybe it is a pity that the only sensor technology that tried to expand highlight headroom by effectively increasing maximum photon count far beyond the normal limits of well size, Fujifilm's SuperCCD SR, has failed in the DSLR marketplace. Or maybe that just shows that some of us are worrying about highlight headroom and DR way too much, and should get back to the time-honored basics of photographic discussions: arguing about lenses!

BJL,
I hope you don't mind if I say that I think you are confusing the issue. We should all know by now that any DR comparisons between images from different DSLRs require the same thorough technique of ensuring a full exposure in both shots (known as an ETTR exposure).

Highlight headroom is an old concept that applied to the film era. Negative film gave more highlight headroom than positive film, and was sometimes preferred for that reason.

With digital, it is assumed that anyone who wishes to compare image qualities from different cameras, whether such qualities be DR, SNR, tonal range or color sensitivity, must compare images that have all been given a 'full' exposure (or ETTR exposure), or such comparisons are not valid.

Comparing images from the same camera that have different exposures, in order to see what visual effect a difference of 1 or 2 stops' exposure may have on the shadows, is fine.
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ErikKaffehr

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Re: Nikon D7000 Dynamic Range
« Reply #53 on: November 19, 2010, 12:08:56 AM »

Hi,

Could you elaborate on this? Are you discussing perception or measurable quantities?

Best regards
Erik


Discussions of SNR should also take into account that SNR varies with spatial frequency.  SNR of 40 at 1000 lph is quite different from SNR=40 at 4000 lph.
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BartvanderWolf

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Re: Nikon D7000 Dynamic Range
« Reply #54 on: November 19, 2010, 08:16:37 AM »

Could you elaborate on this? Are you discussing perception or measurable quantities?

Higher spatial frequencies (fine detail) usualy have lower contrast than lower spatial frequencies (coarse detail). Therefore the detail is obscured by the noise faster. That's BTW why I prefer MTFs, they add more info, but they cannot be summarized to a single figure for comparison as easily.

Cheers,
Bart
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ErikKaffehr

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Re: Nikon D7000 Dynamic Range
« Reply #55 on: November 19, 2010, 11:59:06 AM »

Hi,

I think I got the point now. Modulation transfer is weaker at high frequencies, so the 'S' in the SNR is smaller, correct?

Best regards
Erik



Higher spatial frequencies (fine detail) usualy have lower contrast than lower spatial frequencies (coarse detail). Therefore the detail is obscured by the noise faster. That's BTW why I prefer MTFs, they add more info, but they cannot be summarized to a single figure for comparison as easily.

Cheers,
Bart
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BartvanderWolf

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Re: Nikon D7000 Dynamic Range
« Reply #56 on: November 19, 2010, 12:10:39 PM »

Modulation transfer is weaker at high frequencies, so the 'S' in the SNR is smaller, correct?

Yup, as recorded. The original intensities, especially at the higher spatial frequencies, are modified by the optical chain before the sensor can add its noise to the shot noise of the photons that got through.

I'm just assuming that was what Emil was pointing out.

Cheers,
Bart
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BJL

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Re: Nikon D7000 Dynamic Range
« Reply #57 on: November 19, 2010, 02:58:15 PM »

We should all know by now that any DR comparisons between images from different DSLRs require the same thorough technique of ensuring a full exposure in both shots (known as an ETTR exposure).

Highlight headroom is an old concept that applied to the film era.
My point is actually simpler: many complaints about "inadequate dynamic range" are in reality complaints about "inadequate highlight headroom when I meter the way that I used to with film" because overexposed highlights hit a hard wall with digital that was not there with film. Some sources even try to measure a camera's "highlight DR" and "shadow DR" as separate components, even though the split between the two is a matter of mid-tone placement, which the photographer can adjust.

And as you say, there is a simply-described solution to blown highlights; meter differently, with more attention to the highlights: "ETTL". (Or to get the tolerance for poor exposure choices that negative film can allow, pre-set a negative exposure compensation, and then compensate back up in post.)

That said, this is my point: once highlights are exposed correctly, the dominant limit of noise on IQ will be getting enough light in the main parts of the image, which means getting at least about 500 photons per pixel (or better, somewhere over 1000) in the mid-tones --- and at those photon levels, shot noise overwhelms read noise in modern CMOS sensors, all the way down to three or more stops below the mid-tone subject matter of the scene, and anything darker than that will, in virtually all "artistic" photography [as opposed to surveillance, medical, astronomical etc.] will be printed or otherwise displayed so dark that noise is not a visible problem. So read noise is of little significance, unless one plays games like massively lightening deep shadow regions of the mid-tone print levels: may I call this "shadow peeping"?

I was going to say something abut high ISO case that you mentioned in one post, but that is irrelevant now that we agree that the scenario under discussion is exposures that make use of the full well capacity.
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madmanchan

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Re: Nikon D7000 Dynamic Range
« Reply #58 on: November 19, 2010, 03:02:57 PM »

Correct -- for example, on many modern SLRs if you spot meter an area and take the picture at the recommended exposure (i.e., with the meter needle in the middle), that area will be about 3 to 3.5 stops below sensor saturation. In other words, you could increase the exposure time by ~3 stops before you start clipping.
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Ray

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Re: Nikon D7000 Dynamic Range
« Reply #59 on: November 19, 2010, 11:21:53 PM »

My point is actually simpler: many complaints about "inadequate dynamic range" are in reality complaints about "inadequate highlight headroom when I meter the way that I used to with film" because overexposed highlights hit a hard wall with digital that was not there with film. Some sources even try to measure a camera's "highlight DR" and "shadow DR" as separate components, even though the split between the two is a matter of mid-tone placement, which the photographer can adjust.

Perhaps this was true about 8 years ago before Michael raised the issue of 'expose to the right (of the histogram)' and 2500 threads ensued, over the years, exploring the concept in ever more detail.

I get the impression that most people still shoot in jpeg mode (even with DSLRs) and they mostly shoot subjects which generally make no special demand on the DR capability of their camera and therefore have no complaints about the DR limitations of their camera, assuming such people even understand what DR means.

Speaking for myself, I would say I have a greater number of spoiled shots as a result of blown highlights than spoiled shots as a result of shadows with unacceptable noise. But of course, a concern for one influences the other. A concern for achieving the best shadow detail can lead one to inadvertently overexpose. A concern to avoid overexposure can result in actual underexposure with the consequence of noisier shadows that one would otherwise get.

For this reason I frequently have my camera set on autobracket mode, because memory is so cheap and because the rated 'potential shutter actuations' of modern DSLRs is so high (typically 150,000). What have I to lose?

Quote
That said, this is my point: once highlights are exposed correctly, the dominant limit of noise on IQ will be getting enough light in the main parts of the image, which means getting at least about 500 photons per pixel (or better, somewhere over 1000) in the mid-tones --- and at those photon levels, shot noise overwhelms read noise in modern CMOS sensors, all the way down to three or more stops below the mid-tone subject matter of the scene, and anything darker than that will, in virtually all "artistic" photography [as opposed to surveillance, medical, astronomical etc.] will be printed or otherwise displayed so dark that noise is not a visible problem. So read noise is of little significance, unless one plays games like massively lightening deep shadow regions of the mid-tone print levels: may I call this "shadow peeping"?

That all sounds very reasonable, JBL, but again I think we're slipping into a modern equivalent of the 'horse's mouth' parable. (Let's attempt to find out how many teeth a horse has through appeal only to authority, instead of checking the hard facts for ourselves.)

The testing that I've done with my own equipment would suggest that what you write above is either, simply not true, or if it is true, there are other significant factors which are being overlooked. Those other factors may be, for example, that read noise and shot noise are not the only sources of noise, even though they may be the single most significant sources, or it may be the case that the eye, being less sensitive to detail and noise in the shadows, can accept shot noise in far greater proportions to the signal than would result in a patch on the sensor with an average of 500 photons per pixel, which I really don't think is at all applicable to deep shadows.

For example, in an area of midtones where the pixels might have a mean average of 500 photons per pixel, the average shot noise would be about 22 photons per pixel. Is this correct?

22 photons per 500?? That's only 4.4%. If shot noise overwhelms read noise at this level, we're still only looking at something less than 8.8% total noise within this tonal range. This is not relevant for even modestly deep shadows.

The testing I'm thinking of, that's relevant here, was carried out shortly after I bought a Canon 20D a few years ago. I'd become rather dissatisfied with the rather limited high-ISO capability of the D60, and the 20D was orders of magnitude better.

I'd read on the old Rob Galbraith forum that it was always better to raise ISO than underexpose at base ISO. This was not such a big deal with the D60. An ETTR exposure at ISO 400 was hardly better than the same exposure at ISO 100, after using EC in ACR to raise the levels.

I decided to check this new performance of the 20D at high ISO for myself, taking two shots of the same high-SBR scene at equal exposure, the exposures being just right for an ETTR at ISO 1600. Of course the exposure when used at ISO 100 became a 4-stop underexposure.

I raised the shadows of the ISO 100 shot in ACR, converting both images without sharpening or noise reduction, and to my astonishment the ISO 1600 shot was so much better across the entire tonal range. Whilst the greatest improvement was observable in the shadows, there was a lesser, but still noticeable improvement in the midtones and upper mid-tones, in the ISO 1600 shot.

Now some of you may be thinking, so what! This is old hat. We all know that it's better to use the higher ISO rather than underexpose at base ISO.

But here's the rub. Not with the D7000. There's no image quality advantage in using a higher ISO as an alternative to underexposing at base ISO. So what? You're probably thinking again.

If we refer to the DXOMark graphs, comparing the D7000 with the 20D in 'screen' mode (ie. pixel level), we find that at ISO 1600 a D7000 image, cropped to the 8mp of the 20D is as good in all parameters that DXO measure, SNR, DR, tonal range & color sensitivity.

Or, to put it another way, the image which was underexposed by 4 stops in the 20D at ISO 100 and which looked significantly noisier than the analog-boosted image at ISO 1600 in the 20D, will not look noisier in the D7000 when underexposed 4 stops at ISO 100. It will look about the same as the analog-boosted ISO 1600 shot from the 20D, ie. much improved.

Of course the D7000 has double the pixel count of the 20D and that fact provides for an over all better performance than the 20D at equal image or print size. That's another issue. To see the effects of that, click on 'print' mode on the DXOMark charts. The 20D is left behind in all respects.

Now some of you are probably protesting that the 20D is old technology. This fact I find quite interesting. The 20D is old technology and newer models since then have boasted many useful improvements, but not it seems at the pixel level, with the exception of the most recent 1DMK4 which, at the pixel level, has 2/3rds of a stop greater DR than the 20D at ISO 3200, but only at ISO 3200 (and probably beyond if one extrapolates the graph for the 20D). At lower ISOs the difference is reduced to 1/2 a stop, the minimum difference that might be of any concern.

In fact the 20D pixel seems to very slightly better, over all, than the 1Ds3 pixel, with regard to all parameters. The 5D2 pixel appears to be sometimes very slightly better than the 20D pixel, but not by a margin that one would notice in practice.

It seems that the 20D pixel represented the pinnacle of Canon technological achievement, until the 1D4 pixel edged ahead in respect of DR. Regarding color sensitivity, tonal range and SNR at 18% grey, there appears to be no improvement over the 20D pixel.

Have I successfully counted the horse's teeth without even sticking my head in the horse's mouth?  ;D


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