ISOless sensors, read noise and photography - many questions!

Started 11 months ago | Discussions
boardsy
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ISOless sensors, read noise and photography - many questions!
11 months ago

Accepting the standard definition of exposure as the amount of light registered by the sensor per unit area, and dependent solely on aperture size and shutter speed (not on ISO selection, even if this is used to influence aperture size and shutter speed!), a few questions arise in my mind:

- in order to maximise exposure and DR and minimise noise, do you really need to know your sensor's read noise and ISO DR curves?

Bobn tells us here that the flat read noise characteristic of the Nikon D7000 makes it effectively ISOless:

- if the sensor is effectively ISOless then is base ISO always optimal (providing that you can see enough of the image on your camera to compose and focus in a sub-optimal exposure scenario), or are you as well off raising it in camera (providing highlights are preserved) rather than in RAW/pp?

- is it possible or likely that the camera's ISO implementation is better tuned to its sensor and RAW data than your RAW software? Aside from highlight preservation on exposure, are there other benefits to "doing ISO" in post?

- for a given sensor may it be more effective to raise ISO to some minimum/optimal level vis-a-vis its read noise?

- how do us non-scientists interpret these sensor graphs? E.g. for the Sony NEX C3 (probably the same sensor as my F3, maybe, lol), read noise actually drops down to ISO800 ...but so does DR! Is ISO400 the best compromise here, or should best DR (at ISO200) trump lower read noise (at ISO800)? And could this non-base ISO be valid for all shooting, or just low-light where optimal exposure becomes problematic?

From http://www.sensorgen.info/SonyNEX-C3.html

- finally, could all this be solved for a given sensor by simply shooting a set of fixed aperture/shutter shots at each ISO level, normalising the resultant RAW brightnesses (with the, er, "exposure" slider :-|) and comparing noise (in the shadows, I guess?) by eye?

Apologies for anything (or everything?!) I've misunderstood.

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Alan
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Nikon D7000
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RussellInCincinnati
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agreed, fun to hear if Nex C3 should always be ISO 200
In reply to boardsy, 11 months ago

Boardsy, like you would also enjoy knowing if a Nex C3 should just always be shot at ISO 200, and do any high-ISO "pushing" in raw post-processing. Interesting topic. If someone could explain the answer based on your conveniently provided sensor response graphs, we could apply that logic to all the other sensors that have been rated for quantum efficiency, noise level etc at various ISOs.

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Horshack
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It's better to test to see for yourself
In reply to boardsy, 11 months ago

The DxO data and its derivatives are only quantitative measures and don't capture qualitative aspects of noise like banding, impulse noise, color fidelity, shadow tints, amp glow, etc...

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RussellInCincinnati
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my tests: shadow tints with underexposed ISO 100, but...
In reply to Horshack, 11 months ago

with a Nex C3 maybe I'm not doing something right in post-processing. maybe there is some way to make underexposed "ISO 200" photos brightened in post-processing (raw) look as good as "ISO 3200  photos. Would be a nice simplification in the field...

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edu T
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In the quest of the optimum in-camera ISO setting
In reply to Horshack, 11 months ago

Horshack wrote:

It's better to test to see for yourself

The DxO data and its derivatives are only quantitative measures and don't capture qualitative aspects of noise like banding, impulse noise, color fidelity, shadow tints, amp glow, etc...

While you advise the OP to test & see, I understand that what Alan is looking for in his "last significative paragraph" is just kind of a DIY generic test protocol... so, +1 here!

PS: this "amp glow" is news to me, would it have something to do with tubes ("valves" to Britons) perhaps?

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RussellInCincinnati
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in one sense, pointless to use ISO above 800 on Nex C3
In reply to boardsy, 11 months ago

OK Alan, have put the time in studying the sensorgen site. IF you don't get color casts/banding during your raw post-processing brightening, it appears that there is no point in ever manually setting a Nex C3 to above ISO 800. Because if you do, you are just amplifying "the noise" as much as the brightness and not really getting anything that you couldn't get in post-processing with a lot more finesse and options. Will be checking this out, the practicality of staying at ISO 800, at least with Lightroom 4.4 for Windows if not RawTherapee and LightZone (i.e. latest dcRaw).

Said another way, you might as well brighten a C3 raw digitally, at your leisure if there's not enough light for ISO 800. Just let the raw file "look superficially dark" and figure you'll brighten it in post-processing.

Of course one downside of not setting ISOs above 800, just underexposing, is that you don't get a nice review of the image in-camera, it will always look grim in the playback menu.

With the Nex 7, a quite different sensor in so many ways, there is no point in setting ISOs above 100, if once again your post-processing does not introduce banding or color casts. At least in the narrow sense of noise in a low-light image, you might as well take super dark ISO 100 photos on your Nex 7 and brighten'em in post processing.

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bobn2
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Re: ISOless sensors, read noise and photography - many questions!
In reply to boardsy, 11 months ago

boardsy wrote:

Accepting the standard definition of exposure as the amount of light registered by the sensor per unit area, and dependent solely on aperture size and shutter speed (not on ISO selection, even if this is used to influence aperture size and shutter speed!), a few questions arise in my mind:

- in order to maximise exposure and DR and minimise noise, do you really need to know your sensor's read noise and ISO DR curves?

Bobn tells us here that the flat read noise characteristic of the Nikon D7000 makes it effectively ISOless:

- if the sensor is effectively ISOless then is base ISO always optimal (providing that you can see enough of the image on your camera to compose and focus in a sub-optimal exposure scenario), or are you as well off raising it in camera (providing highlights are preserved) rather than in RAW/pp?

There are other factors to take into account, in no particular order:

- on those graphs the 'base ISO' is not always too accurate, because the sensor may have been run into non-linearity.

- there are qualitative factors as well as the measure of read noise to take into account.

- is it possible or likely that the camera's ISO implementation is better tuned to its sensor and RAW data than your RAW software? Aside from highlight preservation on exposure, are there other benefits to "doing ISO" in post?

It's possible. Nikon, for instance, does some subtle gain adjustments with its cameras. Presumably they wouldn't be doing them unless the engineers thought that they brought some advantage. BTW, I think it's worthwhile distinguishing between 'processing' and 'post processing'. I think the brightness setting is best done in processing (raw conversion), not post-processing.

- for a given sensor may it be more effective to raise ISO to some minimum/optimal level vis-a-vis its read noise?

Yes, I think that's true. The D7000 above is better at 200 for instance.

- how do us non-scientists interpret these sensor graphs? E.g. for the Sony NEX C3 (probably the same sensor as my F3, maybe, lol), read noise actually drops down to ISO800 ...but so does DR! Is ISO400 the best compromise here, or should best DR (at ISO200) trump lower read noise (at ISO800)? And could this non-base ISO be valid for all shooting, or just low-light where optimal exposure becomes problematic?

DR trumps lower read noise if you need it, which is one of those judgements based on experience. A rule of thumb which covers most cameras pretty well is go with ISO but stop about 2 stops faster than base (3 for an APS-C Canon, 4 for a FF one).

From http://www.sensorgen.info/SonyNEX-C3.html

- finally, could all this be solved for a given sensor by simply shooting a set of fixed aperture/shutter shots at each ISO level, normalising the resultant RAW brightnesses (with the, er, "exposure" slider :-|) and comparing noise (in the shadows, I guess?) by eye?

I think personal tests to one's own requirements are always the best - part of getting to know your camera. Just to add, the same goes for you raw processing tools.

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Bob

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Steen Bay
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Re: ISOless sensors, read noise and photography - many questions!
In reply to bobn2, 11 months ago

bobn2 wrote:

I think personal tests to one's own requirements are always the best - part of getting to know your camera. Just to add, the same goes for you raw processing tools.

The subthread below seems to confirm that. It seems that the ISO on the NEX 5N (and maybe other Sony cameras?) just is a tag in the RAW file. No gain/amplification or digital scaling/multiplication at all. Seems that DxO missed that!

http://www.dpreview.com/forums/post/52263644

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boardsy
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Re: In the quest of the optimum in-camera ISO setting
In reply to edu T, 11 months ago

edu T wrote:

Horshack wrote:

It's better to test to see for yourself

The DxO data and its derivatives are only quantitative measures and don't capture qualitative aspects of noise like banding, impulse noise, color fidelity, shadow tints, amp glow, etc...

While you advise the OP to test & see, I understand that what Alan is looking for in his "last significative paragraph" is just kind of a DIY generic test protocol... so, +1 here!

PS: this "amp glow" is news to me, would it have something to do with tubes ("valves" to Britons) perhaps?

Thanks guys, wasn't requesting a test protocol per se, just wondering if such a test as I suggested would be as reliable (and certainly not as simple!) as basing decisions on the graphs; I would have to test the RAW software as well I suppose; I use ACR and could compare RAWTherapee and similar by comparison...

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Alan
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boardsy
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Thanks Russell - my non-scientific example...
In reply to RussellInCincinnati, 11 months ago

RussellInCincinnati wrote:

OK Alan, have put the time in studying the sensorgen site. IF you don't get color casts/banding during your raw post-processing brightening, it appears that there is no point in ever manually setting a Nex C3 to above ISO 800. Because if you do, you are just amplifying "the noise" as much as the brightness and not really getting anything that you couldn't get in post-processing with a lot more finesse and options. Will be checking this out, the practicality of staying at ISO 800, at least with Lightroom 4.4 for Windows if not RawTherapee and LightZone (i.e. latest dcRaw).

Said another way, you might as well brighten a C3 raw digitally, at your leisure if there's not enough light for ISO 800. Just let the raw file "look superficially dark" and figure you'll brighten it in post-processing.

Of course one downside of not setting ISOs above 800, just underexposing, is that you don't get a nice review of the image in-camera, it will always look grim in the playback menu.

With the Nex 7, a quite different sensor in so many ways, there is no point in setting ISOs above 100, if once again your post-processing does not introduce banding or color casts. At least in the narrow sense of noise in a low-light image, you might as well take super dark ISO 100 photos on your Nex 7 and brighten'em in post processing.

Thanks Russell (didn't know you were still lurking around these forums by the way, been a while since you were in the NEX forum?!), good detective work!

Here's a random example of a shot I under-exposed at base ISO200, around 1/30 hand-held, f2 on the FD 35/2 + Lens Turbo focal reducer, just to preserve highlights and see how it turned out after RAW pp in Adobe Camera Raw. The result is pretty good I think, and brighter than the scene was; sorry I didn't take a high ISO shot for comparison, or note how under-exposed I shot it!

It seems you could use high ISO purely to focus and compose (like an open aperture!) and then bring it back down to take the shot!

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Alan
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bobn2
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Re: ISOless sensors, read noise and photography - many questions!
In reply to Steen Bay, 11 months ago

Steen Bay wrote:

bobn2 wrote:

I think personal tests to one's own requirements are always the best - part of getting to know your camera. Just to add, the same goes for you raw processing tools.

The subthread below seems to confirm that. It seems that the ISO on the NEX 5N (and maybe other Sony cameras?) just is a tag in the RAW file. No gain/amplification or digital scaling/multiplication at all. Seems that DxO missed that!

http://www.dpreview.com/forums/post/52263644

The Sony raw coding is unusual, because they use a non-linear 12 bit code (at least in some cameras) - I think we'd want to look closely to convince ourselves that the non-linearity remains the same from ISO to ISO.

Edit: As Iliah's post confirms

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Bob

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Steen Bay
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Re: ISOless sensors, read noise and photography - many questions!
In reply to bobn2, 11 months ago

bobn2 wrote:

Steen Bay wrote:

bobn2 wrote:

I think personal tests to one's own requirements are always the best - part of getting to know your camera. Just to add, the same goes for you raw processing tools.

The subthread below seems to confirm that. It seems that the ISO on the NEX 5N (and maybe other Sony cameras?) just is a tag in the RAW file. No gain/amplification or digital scaling/multiplication at all. Seems that DxO missed that!

http://www.dpreview.com/forums/post/52263644

The Sony raw coding is unusual, because they use a non-linear 12 bit code (at least in some cameras) - I think we'd want to look closely to convince ourselves that the non-linearity remains the same from ISO to ISO.

Edit: AsIliah's post confirms

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Bob

The 'spikes' in (especially) the shadows (to the left) get wider as the ISO increases, but maybe that has something to do with long exposure NR? (suppose that "2, f/2.8" means 2 seconds, f/2.8)

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bobn2
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Re: ISOless sensors, read noise and photography - many questions!
In reply to Steen Bay, 11 months ago

Steen Bay wrote:

bobn2 wrote:

Steen Bay wrote:

bobn2 wrote:

I think personal tests to one's own requirements are always the best - part of getting to know your camera. Just to add, the same goes for you raw processing tools.

The subthread below seems to confirm that. It seems that the ISO on the NEX 5N (and maybe other Sony cameras?) just is a tag in the RAW file. No gain/amplification or digital scaling/multiplication at all. Seems that DxO missed that!

http://www.dpreview.com/forums/post/52263644

The Sony raw coding is unusual, because they use a non-linear 12 bit code (at least in some cameras) - I think we'd want to look closely to convince ourselves that the non-linearity remains the same from ISO to ISO.

Edit: AsIliah's post confirms

-- hide signature --

Bob

The 'spikes' in (especially) the shadows (to the left) get wider as the ISO increases, but maybe that has something to do with long exposure NR? (suppose that "2, f/2.8" means 2 seconds, f/2.8)

I wouldn't expect NR to change the histogram on that scale, it would mean hugely visible smudging if that was true. Think, the nature of NR is to change pixels to very nearly the same tone, but within the same distribution of tomes that already exist. If it goes inventing new tones, the results will look very strange indeed.

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Bob

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boardsy
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Re: ISOless sensors, read noise and photography - many questions!
In reply to bobn2, 11 months ago

bobn2 wrote:

boardsy wrote:

Accepting the standard definition of exposure as the amount of light registered by the sensor per unit area, and dependent solely on aperture size and shutter speed (not on ISO selection, even if this is used to influence aperture size and shutter speed!), a few questions arise in my mind:

- in order to maximise exposure and DR and minimise noise, do you really need to know your sensor's read noise and ISO DR curves?

Bobn tells us here that the flat read noise characteristic of the Nikon D7000 makes it effectively ISOless:

- if the sensor is effectively ISOless then is base ISO always optimal (providing that you can see enough of the image on your camera to compose and focus in a sub-optimal exposure scenario), or are you as well off raising it in camera (providing highlights are preserved) rather than in RAW/pp?

There are other factors to take into account, in no particular order:

- on those graphs the 'base ISO' is not always too accurate, because the sensor may have been run into non-linearity.

- there are qualitative factors as well as the measure of read noise to take into account.

Sorry, this is all a bit opaque to me - what is the upshot for practical purposes?

- is it possible or likely that the camera's ISO implementation is better tuned to its sensor and RAW data than your RAW software? Aside from highlight preservation on exposure, are there other benefits to "doing ISO" in post?

It's possible. Nikon, for instance, does some subtle gain adjustments with its cameras. Presumably they wouldn't be doing them unless the engineers thought that they brought some advantage. BTW, I think it's worthwhile distinguishing between 'processing' and 'post processing'. I think the brightness setting is best done in processing (raw conversion), not post-processing.

Do you mean: processing means RAW software (ACR, LR etc), and post-processing applies to JPG (PS, GIMP etc)?

- for a given sensor may it be more effective to raise ISO to some minimum/optimal level vis-a-vis its read noise?

Yes, I think that's true. The D7000 above is better at 200 for instance.

But it has less DR & Sat Cap and equal read noise at 200 vs 100?

- how do us non-scientists interpret these sensor graphs? E.g. for the Sony NEX C3 (probably the same sensor as my F3, maybe, lol), read noise actually drops down to ISO800 ...but so does DR! Is ISO400 the best compromise here, or should best DR (at ISO200) trump lower read noise (at ISO800)? And could this non-base ISO be valid for all shooting, or just low-light where optimal exposure becomes problematic?

DR trumps lower read noise if you need it, which is one of those judgements based on experience. A rule of thumb which covers most cameras pretty well is go with ISO but stop about 2 stops faster than base (3 for an APS-C Canon, 4 for a FF one).

You mean raise ISO in-camera as required, up to 2 (APS-C), 3 (APS-C Canon), or 4 (FF) stops?

From http://www.sensorgen.info/SonyNEX-C3.html

- finally, could all this be solved for a given sensor by simply shooting a set of fixed aperture/shutter shots at each ISO level, normalising the resultant RAW brightnesses (with the, er, "exposure" slider :-|) and comparing noise (in the shadows, I guess?) by eye?

I think personal tests to one's own requirements are always the best - part of getting to know your camera. Just to add, the same goes for you raw processing tools.

Does what I outlined above make sense?

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Bob

Thanks for your help! One other point - why would ISO800 read noise be better than base ISO200, as in the NEX-C3 sensor above? Seems counter-intuitive - something to do with good ADC or other sensor gain up to that point, and just digital processing (brightness mapping) applied after that? Just vague ideas of mine, not an engineer!

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Alan
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bobn2
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Re: ISOless sensors, read noise and photography - many questions!
In reply to boardsy, 11 months ago

boardsy wrote:

bobn2 wrote:

There are other factors to take into account, in no particular order:

- on those graphs the 'base ISO' is not always too accurate, because the sensor may have been run into non-linearity.

- there are qualitative factors as well as the measure of read noise to take into account.

Sorry, this is all a bit opaque to me - what is the upshot for practical purposes?

Well, the real upshot is, you might use those graphs to help you select, if you value 'ISOless', but you're best off doing some test shots (as there is even sample to sample variation) to work out how best to use your camera). Things like pattern noise and pixel response non-uniformity are not included in the above graphs. Canon's particularly are bad for pattern noise, which means their useable range is less than indicated.

- is it possible or likely that the camera's ISO implementation is better tuned to its sensor and RAW data than your RAW software? Aside from highlight preservation on exposure, are there other benefits to "doing ISO" in post?

It's possible. Nikon, for instance, does some subtle gain adjustments with its cameras. Presumably they wouldn't be doing them unless the engineers thought that they brought some advantage. BTW, I think it's worthwhile distinguishing between 'processing' and 'post processing'. I think the brightness setting is best done in processing (raw conversion), not post-processing.

Do you mean: processing means RAW software (ACR, LR etc), and post-processing applies to JPG (PS, GIMP etc)?

Software packages mix and match. What I mean by 'processing' is the act of assigning brightnesses and colours to the pixel values, which are essentially photon counts. Basically, you want to assign the brightness you want at that stage, rather than later. Essentially, one might expect the processing results in a tiff or jpeg file, post processing would take that file and work with it. The boundaries are a bit confused because many processors (raw converters) include operations subsequent to conversion, and many PP tools can convert a raw image.

- for a given sensor may it be more effective to raise ISO to some minimum/optimal level vis-a-vis its read noise?

Yes, I think that's true. The D7000 above is better at 200 for instance.

But it has less DR & Sat Cap and equal read noise at 200 vs 100?

Sur, but saturation capacity and DR are only of interest if you're going to use them. If your scene and chosen exposure doesn't include anything that will blow out at 200, then 200 is as good as 100, and maybe a bit better in some cases.

- how do us non-scientists interpret these sensor graphs? E.g. for the Sony NEX C3 (probably the same sensor as my F3, maybe, lol), read noise actually drops down to ISO800 ...but so does DR! Is ISO400 the best compromise here, or should best DR (at ISO200) trump lower read noise (at ISO800)? And could this non-base ISO be valid for all shooting, or just low-light where optimal exposure becomes problematic?

DR trumps lower read noise if you need it, which is one of those judgements based on experience. A rule of thumb which covers most cameras pretty well is go with ISO but stop about 2 stops faster than base (3 for an APS-C Canon, 4 for a FF one).

You mean raise ISO in-camera as required, up to 2 (APS-C), 3 (APS-C Canon), or 4 (FF) stops?

the 4 stops for FF was Canon only. Yes, essentially use that as your fixed working ISO, lowere it if you need more highlight headroom.

From http://www.sensorgen.info/SonyNEX-C3.html

- finally, could all this be solved for a given sensor by simply shooting a set of fixed aperture/shutter shots at each ISO level, normalising the resultant RAW brightnesses (with the, er, "exposure" slider :-|) and comparing noise (in the shadows, I guess?) by eye?

I think personal tests to one's own requirements are always the best - part of getting to know your camera. Just to add, the same goes for you raw processing tools.

Does what I outlined above make sense?

Yes, you'd be characterising your own workflow, which always makes sense. On the basis of what you learn, you might decide to change your workflow a bit.

Thanks for your help! One other point - why would ISO800 read noise be better than base ISO200, as in the NEX-C3 sensor above? Seems counter-intuitive - something to do with good ADC or other sensor gain up to that point, and just digital processing (brightness mapping) applied after that? Just vague ideas of mine, not an engineer!

The question is at which stage in the signal chain does the noise arise. Typically high low ISO read noise is caused by high late chain noise (say from the ADC). Raising the analog gain before that stage makes its noise less significant. The Sony column ADC's are very good, but ironically Sony seems to get less out of them than other manufacturers. Perhaps they run them faster, or are a bit less cute in optimising the gain settings.

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boardsy
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Re: ISOless sensors, read noise and photography - many questions!
In reply to bobn2, 11 months ago

bobn2 wrote:

boardsy wrote:

bobn2 wrote:

Yes, I think that's true. The D7000 above is better at 200 for instance.

But it has less DR & Sat Cap and equal read noise at 200 vs 100?

Sur, but saturation capacity and DR are only of interest if you're going to use them. If your scene and chosen exposure doesn't include anything that will blow out at 200, then 200 is as good as 100, and maybe a bit better in some cases.

A bit better how, in what cases - you're getting lower DR and equal read noise at 200?

- how do us non-scientists interpret these sensor graphs? E.g. for the Sony NEX C3 (probably the same sensor as my F3, maybe, lol), read noise actually drops down to ISO800 ...but so does DR! Is ISO400 the best compromise here, or should best DR (at ISO200) trump lower read noise (at ISO800)? And could this non-base ISO be valid for all shooting, or just low-light where optimal exposure becomes problematic?

DR trumps lower read noise if you need it, which is one of those judgements based on experience. A rule of thumb which covers most cameras pretty well is go with ISO but stop about 2 stops faster than base (3 for an APS-C Canon, 4 for a FF one).

You mean raise ISO in-camera as required, up to 2 (APS-C), 3 (APS-C Canon), or 4 (FF) stops?

the 4 stops for FF was Canon only. Yes, essentially use that as your fixed working ISO, lowere it if you need more highlight headroom.

You mean not just as required by low light, to choose lowest read noise despite lower DR? Interesting, I wouldn't have expected that - so  DR would only trump read noise in high DR scenes e.g. midday sun & dark shadows?

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Alan
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Steen Bay
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Re: ISOless sensors, read noise and photography - many questions!
In reply to bobn2, 11 months ago

bobn2 wrote:

Steen Bay wrote:

bobn2 wrote:

Steen Bay wrote:

bobn2 wrote:

I think personal tests to one's own requirements are always the best - part of getting to know your camera. Just to add, the same goes for you raw processing tools.

The subthread below seems to confirm that. It seems that the ISO on the NEX 5N (and maybe other Sony cameras?) just is a tag in the RAW file. No gain/amplification or digital scaling/multiplication at all. Seems that DxO missed that!

http://www.dpreview.com/forums/post/52263644

The Sony raw coding is unusual, because they use a non-linear 12 bit code (at least in some cameras) - I think we'd want to look closely to convince ourselves that the non-linearity remains the same from ISO to ISO.

Edit: AsIliah's post confirms

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Bob

The 'spikes' in (especially) the shadows (to the left) get wider as the ISO increases, but maybe that has something to do with long exposure NR? (suppose that "2, f/2.8" means 2 seconds, f/2.8)

I wouldn't expect NR to change the histogram on that scale, it would mean hugely visible smudging if that was true. Think, the nature of NR is to change pixels to very nearly the same tone, but within the same distribution of tomes that already exist. If it goes inventing new tones, the results will look very strange indeed.

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Bob

We have many unanswered questions here, but I find it very interesting that the NEX 5N RAW files seem to be able to 'handle' the same exposure without clipping at all (or at least most) ISOs. Seems to me that DxO's Measured ISO therefore also should be the same at all (or most) ISOs.

PS - That should make it possible to shoot 'ISO-less' with the 5N, and still get JPEGs with the 'correct' brightness. Or rather, it'll give you the advantage of 'ISO-less' shooting (more headroom), without actually shooting 'ISO-less'.

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rubank
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Re: It's better to test to see for yourself
In reply to Horshack, 11 months ago

Horshack wrote:

The DxO data and its derivatives are only quantitative measures and don't capture qualitative aspects of noise like banding, impulse noise, color fidelity, shadow tints, amp glow, etc...

Beware of trial and error, some "scientists" will knock you for it

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rubank
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Re: ISOless sensors, read noise and photography - many questions!
In reply to bobn2, 11 months ago

bobn2 wrote:


I think personal tests to one's own requirements are always the best -

I hardly beleive my eyes

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Reilly Diefenbach
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Re: my tests: shadow tints with underexposed ISO 100, but...
In reply to RussellInCincinnati, 11 months ago

Not going to happen.

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