Poll: should we lie to beginners?

[Detail Man]

chary zp wrote:

bobn2 wrote:

In a few recent posts, I have given my views about the well known Cambridge in Colour website, which I believe cannot be recommended to beginners because it contains many factual and theoretical errors (a partial critique is here ). I have been told that the theory is not important to beginners, and that the correctness of the information given on sites such as CIC is only of interest to scientists and engineers. So, the question is, should we be teaching beginners incorrect theory?

Actually, I teach some beginners some basics how to use digital cameras on quite a regular basis. I am a screener in one specific gallery and the screening happens in the form of "this is wrong, do it better, and this is how".

And I do not worry about the circle of confusion whatever technicalities or whether larger sensors have larger DoF.

I myself like the phrase "Circle of Certainty" better. After all, it's all about "selling confidence" ...

I stick only to shutter speed - aperture - iso = darkness trinity ...

I like that (the "Darkness Trinity"). Look on the dim side ! Better than the "faux-Exposure" bit.

... and focal lenght - F-number - focus distance = DOF trinity, ...

Do you call lens-system F-Ratio both "aperture" and "F-Number" in these respective cases ?

... because they are not going to use a range of sensor sizes in their work, they are going to use their APSC DSLR probably for ever, not even getting up to FF or down to m3/4.

According to the link, I am teaching them lies, because ISO is not a part of the "exposure".

I would instead say that you are foregoing techniques that help to maximize Signal/Noise Ratios.

Yet, my students can easily see the effects those three parts have on the final darkness of the picture and the final appearance of it (noise, camera shake, motion blur, DoF...).

Well, I suppose that the more visible the image-noise is, the less students might forget about it.

So for them, ISO is logically a part of exposure calculation and equivalency equasions.

What "equivalency equasions" would that be (when, as you say, you teach one format only) ?

Why should I confuse them by "the truth" that in fact it is not?

Amazing.

They can also easily see the differences in DoF if they change F-number or focal lenght. That's what they need to know and know how to use.

Seems like the bit about DOF being proportional to the inverse-square of the Focal Length could get a bit "hairy". (Then again), in an equal FOV case (where Camera to Subject Distance is changed along with Focal Length), DOF simplifies to directly proportionality with F-Number.

They do not need to argue with technical geeks about what the real truth here is, ...

Thank goodness.

... they need to know what to set on their cameras to have their pictures look the way they want and need them look. And setting correct iso according to the other two parts is the correct exposure equation, whether it is the real truth or not.

80 percent of life is showing up. (- Woody Allen)

I suppose that the other 20 percent is probably about getting paid money to instill confidence ?

 

[Great Bustard]

Detail Man wrote:

80 percent of life is showing up. (- Woody Allen)

I suppose that the other 20 percent is probably about getting paid money to instill confidence ?

Nah -- the other 20% is looking good when you show up.

 

[Steen Bay]

gollywop wrote:

Steen Bay wrote:

gollywop wrote:

Oh yes, I'm fully aware you had an incorrect notion of a "properly exposed" image. You still do.

OK, then please tell me what the correct definition of a "properly exposed" image is.

Good god, man, that has been one of the central issues in all these "exposure" threads and the whole distinction between exposure and brightening. Are you now telling me that you have been engaging in these discussions without even knowing what the underlying issue are? Don't you think you should have done your homework before coming to class?

--
gollywop

I'm perfectly aware what the underlying issues are. My point was that there isn't such a thing as a 'correct' definition of a 'properly exposed' image, so my definition can be just as good as yours.

 

[Steen Bay]

Detail Man wrote:

gollywop wrote:

Steen Bay wrote:

... please tell me what the correct definition of a "properly exposed" image is.

Good god, man, that has been one of the central issues in all these "exposure" threads and the whole distinction between exposure and brightening. Are you now telling me that you have been engaging in these discussions without even knowing what the underlying issue are? Don't you think you should have done your homework before coming to class?

A couple of years ago, Steen reported that (when used), his cameras were used to record JPGs only, and that he (at that time) had never sorted through, or post-processed, any of the shots.

Re: Steen's gear and photography

Steen Bay wrote:

Detail Man wrote:

I see from your DPR gallery "gear list that (in addition to owning a FZ28 like me, you own a G1). And I see that you are quite a Canon and Fuji fellow, as well (with quite a lens collection, indeed).

Not Fuji, but lots of Canon stuff and a bit Panasonic. Most of it is (unfortunately) just collecting dust. These days I'm mostly shooting with my SX10/SX40 'stuper-zooms' (JPEG-only, of course ;-)).

... I find absolutely no images from you on the internet, whatsoever. (What I think may well be your) Flickr pages only feature your favorite images by other people .

I'd be interested in seeing some of your favorite personally accomplished photographic efforts !

And so would I, but the problem is that that I enjoy the shooting much more than the post processing. Guess that I have about 80-90k images waiting on the HD, and just to find/select the 1-2% that deserves a closer look would take months. Wish that i had a web gallery, but maybe it'll never happen.

Talk is sometimes somewhat engaging sometimes, but imagery can say much more about what we actually do with out little photographic machines, and how we "see" through our cameras, etc. ...

http://www.dpreview.com/forums/post/39843386

Don't know what actual photographic activities have transpired since that time, or whether his time has been spent on the internet discussing weighty issues with "the best and the brightest". Perhaps Steen might tell us about any actual photography activity (including any RAWs) since ?

Sorry, not much new to tell. My HD collection of unfinished images is growing steadily, and maybe 1k or so of images with autumn colors will hopefully be added in the next couple of months (my absolute favorite time of the year). And btw, when I said "JPEG-only, of couse", it was because Canon superzooms up to (and including) SX40 don't shoot RAW. My SX50 can shoot RAW, and my relatively new Sony A58 SLT camera too, of course, but whether I do it or not, that I'll keep as my little secret. ;-)

 

[Glen Barrington]

In absolute terms, if you don't do into ALL the detail and complex relationships that make up an issue, aren't you presenting a false image of that issue? The practical simplification of all sorts of things can present a false image that still allows people to make reasonably functional decisions.

The goal varies from person to person, some people want full knowledge, others want to know just enough to make a "reasonably" informed decision. (And THEY get to decide what is 'reasonable')

 

[Detail Man]

Glen Barrington wrote:

In absolute terms, if you don't do into ALL the detail and complex relationships that make up an issue, aren't you presenting a false image of that issue? The practical simplification of all sorts of things can present a false image that still allows people to make reasonably functional decisions.

Practical simplification implies a reasonable accuracy - not a ****-eyed joke based on pure fallacy.

The goal varies from person to person, some people want full knowledge, others want to know just enough to make a "reasonably" informed decision. (And THEY get to decide what is 'reasonable').

It is really quite simple. The issue is the maximization of image SNRs due to Photon Shot Noise.

Ditch the "ISO" joke (which, in describing only one single point in a non-linear system's transfer-function, is an even crueler joke than 95% of folks even imagine), replace it with Scene Luminance in said "Holy Triangle", and the result is something that (actually) works in controlling and maximizing SNR due to Photon Shot Noise. The scaling of the image-sensor data (Image Brightness, and the entire concept of "ISO ratings" themselves) is absolutely meaningless outside of JPEGs encoded in sRGB color-space.

The "Exposure Triangle" is patently on its face pure misleading garbage, and the defensive, long-winded, and incredibly uninformed reactions exhibited by its "defenders" only serves to underscore the fact that as technology becomes more specialized, human curiosity and intellegence is devolving at ever increasing rates. The modern mind has become flaccid and docile - and the most troubling thing about the situation is how blind people are to their own ignorance.

People can talk all they want about what profound and deep knowledge that they (think) they learned in school - but if they cannot get their heads around something so relatievly simple and basic (and important) as sensor-level Exposure - then they might as well have not wasted their time with all the pomp and circumstance of sitting on their laurels holding a sheepskin diploma.

It has been shown that very few college graduates (in the US, anyway) after all their impressive sounding courses completed can even figure out how to hook up a light-bulb to a battery. I am beginning to get the feeling that such stellar brilliance is not limited only to the US.

That's fine. However, when people's technical knowledge is that limited, they should honestly admit it, and actually listen to (rather than defensively criticize) people as knowledgeable as the OP.

 

[Paul B Jones]

Or should we point out that given the communication norms on DPR it is virtually impossible for us to distinguish angry pedantry from expertise on this site.

 

[Detail Man]

Andre Affleck wrote:

Detail Man wrote:

Andre Affleck wrote:

Andre Affleck wrote:

Iliah Borg wrote:

If the incorrect information affects the shooting negatively it is a big issue.

Another example would be http://photographylife.com/what-is-iso-in-photography people get

So opening the proverbial can of worms again, does understanding the true definition of ISO bring a shift in paradigm on ones photographic technique?

Maybe let's put it differently, when you look at a shot, how do you know the exposure is correct?

The same regardless of my understanding of ISO.

It appears that you may well have made Iliah's intended point beautifully. (My interpretation is that) his point is that without an awareness of, and control over, sensor-level Exposure when capturing a shot, there is no way (by simply viewing the image later) to determine whether the Signal/Noise Ratio could have been better by simply viewing the image after "brightening".

If that was his point the he's just skating around question. My question is in the context of photographic technique, not about how it looks later.

"Photographic technique" is only assessable by looking at the final results of all related efforts ...

So I ask again, maybe differently this time. How would knowing ISO was not part of exposure change my shooting technique?

Again, the point is to be aware of, and control, sensor-level Exposure to maximize Signal/Noise Ratio. Thinking about "ISO settings" is like fretting about the setting of an audio volume-control. It has nothing to do with the quality of the music produced - only its relative volume level.

Would I not make the same decisions regardless?

Not necessarily. That's just the point. If it did not affect your settings, it would mean nothing.

I'd like to think it would improve technique, but I haven't seen evidence to support that. Perhaps discribe a scenario or post an example?

"Technique" is utterly subjective to evaluate. One person's "ceiling" may be another person's "floor". (I think) that you have missed Iliah's intended point (which is nothing new for him).

Minimize F-Number and Shutter Speed as much as practicable (given desired DOF and camera/subject-stability). Select the ISO setting last (if recording JPGs or RAWs) - or even leave ISO at base setting (if recording RAWs) if you want to. Have a look for yourself at the differences. The improvement in SNR resulting from Photon Shot Noise will be proportional to the square-root of the ratio of the relative increase in sensor-level Exposure that you achieve.

 

[chary zp]

Great Bustard wrote:

chary zp wrote:

bobn2 wrote:

In a few recent posts, I have given my views about the well known Cambridge in Colour website, which I believe cannot be recommended to beginners because it contains many factual and theoretical errors (a partial critique is here ). I have been told that the theory is not important to beginners, and that the correctness of the information given on sites such as CIC is only of interest to scientists and engineers. So, the question is, should we be teaching beginners incorrect theory?

Actually, I teach some beginners some basics how to use digital cameras on quite a regular basis. I am a screener in one specific gallery and the screening happens in the form of "this is wrong, do it better, and this is how".

And I do not worry about the circle of confusion whatever technicalities or whether larger sensors have larger DoF. I stick only to shutter speed - aperture - iso = darkness trinity and focal lenght - F-number - focus distance = DOF trinity, because they are not going to use a range of sensor sizes in their work, they are going to use their APSC DSLR probably for ever, not even getting up to FF or down to m3/4.

According to the link, I am teaching them lies, because ISO is not a part of the "exposure". Yet, my students can easily see the effects those three parts have on the final darkness of the picture and the final appearance of it (noise, camera shake, motion blur, DoF...). So for them, ISO is logically a part of exposure calculation and equivalency equasions. Why should I confuse them by "the truth" that in fact it is not?

This is because you think exposure is how bright or dark a photo has, and your students think that, 'cause that's what you taught them.

Yeah. We do not have to worry about "only aperture and shutter speed is exposure and iso is not the part", because what we do is solve the problem why the picture is so dark? Well, I need some aperture (F-number, in this case say F8) to get required DoF and sharpness-detailness (lens' F-number sweet spot), and also need a sufficiently short shutter speed to freeze the movement of a fast going train. Slighthly blurred image is not really what we want, is it? So, 1/800s is our answer here. This is the exposure, this is what you need to set in your camera and you will get the required picture. But, but, my picture is too dark. Well, what iso do you have? 100. It doesn't matter, the exposure is correct. Full stop.

Not really. Iso is a part of the calculation to get the right darkness and in my language, we call it the exposure of the photo, you also have the exposure compensation in the camera, don't you? That EV/(+/-) button. But with M F8 1/800s Auto-ISO, what does the camera do? Shifts ISO to get required darkness. Or in ASP modes when you get to a limit of the camera, like lowest F-number of the lens and the scene is too dark, what do you change? So somehow it has to have some effect.

And really, with different ISO values resulting in different looking pictures, obviously, for our purposes we include it in the exposure calculation.

They can also easily see the differences in DoF if they change F-number or focal lenght. That's what they need to know and know how to use.

Or just frame tighter -- that seems to be a favorite technique for many in their quest to obliterate the background.

Actually, as I wrote, it is quite a special gallery. Mostly landscapes, but if you want to compose at such and such focal length and have everything "sharp", you need this and that F-number. If you have shorter focal length, you need smaller F-number (and thus can afford lower ISO for lower noise) for the same required sharpness of the frame in the means of DoF.

In fact, we mostly solve the problem how to get the image sharp, not with shallow DoF. There are some cases with shallow DoF in special landscape situations, but again, we discuss with our students in the means of "this F number is too high for the intended picture, go lower". Compositions are usually given, tighter framing is in the vast majority not the required method.

They do not need to argue with technical geeks about what the real truth here is, they need to know what to set on their cameras to have their pictures look the way they want and need them look. And setting correct iso according to the other two parts is the correct exposure equation, whether it is the real truth or not.

Sure, sure. The sun rises, the sun sets. Unless you're putting satellites in orbit, why do you need to know more?

Exactly.

If you want to argue, exposure. What adjectives do you use to describe it? We use "longer shorter" for when you change shutter speed (light trails versus frozen hi-speed motion), and "darker lighter", when you change the exposure trinity whatever way so that the photo is darker or lighter in the end. At that point, the fact that changing F-number changed DoF and image sharpness, changing shutter speed changes the freezment of the movement or shaking of the camera, and changing ISO changes the noise, all these things are irrelevant at that moment. But hey, changing ISO is a part of this. If the photo is under- or overexposed, which means that the photo is too dark or too light, what can you do to get the correct exposure (see EV(+/-)), correctly dark picture? Only change shutter speed or F-number?

 

[Austinian]

Paul B Jones wrote:

Or should we point out that given the communication norms on DPR it is virtually impossible for us to distinguish angry pedantry from expertise on this site.

It can be difficult at times, for sure. For someone without a general technical background it could be very difficult indeed.

I generally look for logical consistency of statements, and look at external information sources for the subjects discussed. When possible, if I think it's useful I'll try to design some simple experiment(s) to test the various ideas presented. The posters whose comments correspond best to the results I see gain credibility.

 

[chary zp]

Detail Man wrote:

chary zp wrote:

bobn2 wrote:

In a few recent posts, I have given my views about the well known Cambridge in Colour website, which I believe cannot be recommended to beginners because it contains many factual and theoretical errors (a partial critique is here ). I have been told that the theory is not important to beginners, and that the correctness of the information given on sites such as CIC is only of interest to scientists and engineers. So, the question is, should we be teaching beginners incorrect theory?

Actually, I teach some beginners some basics how to use digital cameras on quite a regular basis. I am a screener in one specific gallery and the screening happens in the form of "this is wrong, do it better, and this is how".

And I do not worry about the circle of confusion whatever technicalities or whether larger sensors have larger DoF.

I myself like the phrase "Circle of Certainty" better. After all, it's all about "selling confidence" ...

I stick only to shutter speed - aperture - iso = darkness trinity ...

I like that (the "Darkness Trinity"). Look on the dim side ! Better than the "faux-Exposure" bit.

... and focal lenght - F-number - focus distance = DOF trinity, ...

Do you call lens-system F-Ratio both "aperture" and "F-Number" in these respective cases ?

Frankly, due to language barriers, I am not sure I understand your question. What matters to me is the number I set on my camera. That is F2,8 or F8. In my language we say "to aperture it down" or "to aperture it open", we use prefixes, I believe that the English equivalents are "to step down" and "step up?". We deal with real life problems, such as a landscape style photo taken with kit lens shot close to the end of the range full open (eg. 18-105 @ 90mm F5,3). Not really sharpest of the photos, you can imagine. What advice do we give? "You have to use higher aperture, you need to aperture it down / step it down" (higher means higher number, because this is what they understand. F8 is higher than F2,8). We do not bother telling them "narrower aperture" because this, even though it is true, is bit too much for their thinking, because they do not need to know how aperture blades work, they need to know that F8 is more than F5,3 and it makes a sharper image, as one of its effects.

It is probably just another example of "lies to the children" as in Terry Pratchett's Discworld Science series, which probably sums the whole discussion up. D

... because they are not going to use a range of sensor sizes in their work, they are going to use their APSC DSLR probably for ever, not even getting up to FF or down to m3/4.

According to the link, I am teaching them lies, because ISO is not a part of the "exposure".

I would instead say that you are foregoing techniques that help to maximize Signal/Noise Ratios.

Actually, not any of their business, because absolute majority of them are enthusiasts who will never go beyond DX. They just like taking pictures and DX cameras are a good balance of IQ/money.

Yet, my students can easily see the effects those three parts have on the final darkness of the picture and the final appearance of it (noise, camera shake, motion blur, DoF...).

Well, I suppose that the more visible the image-noise is, the less students might forget about it.

Frankly, language barrier here. What do you mean? You mean that if they see the noise more, they are more aware of it? They are bothered by the noise, but it is a part of the game, if you need fast shutter speed and narrow aperture for the type of photos they take, the high iso and corresponding noise is the necessary evil.

So for them, ISO is logically a part of exposure calculation and equivalency equasions.

What "equivalency equasions" would that be (when, as you say, you teach one format only) ?

Easy to explain. I want to shoot a scene and the camera says that I need F4 iso100 1/1250s. Well, F4 is too low here, I need more, say F8 because of DoF and Sweetspot. Then I don't need 1/1250, it is a bit too much, 1/800 would be just fine. The quiestion is, what ISO do I need to have "right dark" picture? This kind of equations. Sorry for the typo in the first post. If I am right, the math says iso250.

Why should I confuse them by "the truth" that in fact it is not?

Amazing.

Depends on the point of view. What they need to know is what to change in the camera to get a change in the darkness of the photo, which we call exposure. The final exposure. If exposure is only aperture x shutter speed, and changing ISO also changes the final darkness, the final exposure, plus if you change two of the three in the exposure calculation and you still get "more or less" the same dark picture, then ISO is somehow a part of the exposure (calculation) and while the truth presented in the ling in the OP's first post says that ISO is not a part of exposure, my students can clearly see that for them it is, because they do not give a spit about the amount of light which hits the surface due to the interlaboration of the two (aperture, shutter speed) or whatever, they use the three (the previous two AND iso) to make the right dark picture. Still amazing? Not for them.

They can also easily see the differences in DoF if they change F-number or focal lenght. That's what they need to know and know how to use.

Seems like the bit about DOF being proportional to the inverse-square of the Focal Length could get a bit "hairy". (Then again), in an equal FOV case (where Camera to Subject Distance is changed along with Focal Length), DOF simplifies to directly proportionality with F-Number.

Actually, we do not do any sophisticated calculations, the simple fact that "the longer lens the shallower DoF (at the same F-number and focal distance)" or "the smaller F-number the shallower DoF (at the same focal length and focal distance)" is just what then need to be aware of and what to do to change it.

They do not need to argue with technical geeks about what the real truth here is, ...

Thank goodness.

Exactly.

... they need to know what to set on their cameras to have their pictures look the way they want and need them look. And setting correct iso according to the other two parts is the correct exposure equation, whether it is the real truth or not.

80 percent of life is showing up. (- Woody Allen)

I suppose that the other 20 percent is probably about getting paid money to instill confidence ?

Frankly, I don't get this one, maybe a language barrier.

 

[Andre Affleck]

Detail Man wrote:

Andre Affleck wrote:

Detail Man wrote:

Andre Affleck wrote:

Andre Affleck wrote:

Iliah Borg wrote:

If the incorrect information affects the shooting negatively it is a big issue.

Another example would be http://photographylife.com/what-is-iso-in-photography people get

So opening the proverbial can of worms again, does understanding the true definition of ISO bring a shift in paradigm on ones photographic technique?

Maybe let's put it differently, when you look at a shot, how do you know the exposure is correct?

The same regardless of my understanding of ISO.

It appears that you may well have made Iliah's intended point beautifully. (My interpretation is that) his point is that without an awareness of, and control over, sensor-level Exposure when capturing a shot, there is no way (by simply viewing the image later) to determine whether the Signal/Noise Ratio could have been better by simply viewing the image after "brightening".

If that was his point the he's just skating around question. My question is in the context of photographic technique, not about how it looks later.

"Photographic technique" is only assessable by looking at the final results of all related efforts ...

So I ask again, maybe differently this time. How would knowing ISO was not part of exposure change my shooting technique?

Again, the point is to be aware of, and control, sensor-level Exposure to maximize Signal/Noise Ratio. Thinking about "ISO settings" is like fretting about the setting of an audio volume-control. It has nothing to do with the quality of the music produced - only its relative volume level.

Would I not make the same decisions regardless?

Not necessarily. That's just the point. If it did not affect your settings, it would mean nothing

Then give me an instance where it wouldn't. It's a simple request and everyone has evaded it including you. Give me a scenario where gaining the insight that "ISO was not part of exposure" has led one to a better (or even different) decision than a person less enlightened. Just one. Patiently waiting...

.

I'd like to think it would improve technique, but I haven't seen evidence to support that. Perhaps discribe a scenario or post an example?

"Technique" is utterly subjective to evaluate. One person's "ceiling" may be another person's "floor". (I think) that you have missed Iliah's intended point (which is nothing new for him).

No, I got the point. He had missed mine (I think). Perhaps his silence is evidence that he got it now?

Minimize F-Number and Shutter Speed as much as practicable (given desired DOF and camera/subject-stability). Select the ISO setting last (if recording JPGs or RAWs) - or even leave ISO at base setting (if recording RAWs) if you want to. Have a look for yourself at the differences. The improvement in SNR resulting from Photon Shot Noise will be proportional to the square-root of the ratio of the relative increase in sensor-level Exposure that you achieve.

 

[chary zp]

Great Bustard wrote:

Detail Man wrote:

80 percent of life is showing up. (- Woody Allen)

I suppose that the other 20 percent is probably about getting paid money to instill confidence ?

Nah -- the other 20% is looking good when you show up.

Sorry, I am not native. My dictionary says, that "show up" means either to "appear", or to "dishonour somebody or self, diminish, embarrass". Lovely confusing word. What is meant by all that Detail Man and Great Bustard wrote?

 

[Detail Man]

chary zp wrote:

Great Bustard wrote:

Detail Man wrote:

80 percent of life is showing up. (- Woody Allen)

I suppose that the other 20 percent is probably about getting paid money to instill confidence ?

Nah -- the other 20% is looking good when you show up.

Sorry, I am not native. My dictionary says, that "show up" means either to "appear", or to "dishonour somebody or self, diminish, embarrass". Lovely confusing word. What is meant by all that Detail Man and Great Bustard wrote?

Not to worry, my friend. "Showing up" (in this context) simply means "to appear" - as one would appear for an appointment for a class, or appear at a work-site of their employment. Woody Allen was just saying that to physically appear and to be a part of such experiences in life is significant. There is a certain "truth" in that. To "be there" in body, as well as in mind.

Best Regards,

DM

 

[Detail Man]

Andre Affleck wrote:

Detail Man wrote:

Andre Affleck wrote:

Detail Man wrote:

Andre Affleck wrote:

Andre Affleck wrote:

Iliah Borg wrote:

If the incorrect information affects the shooting negatively it is a big issue.

Another example would be http://photographylife.com/what-is-iso-in-photography people get

So opening the proverbial can of worms again, does understanding the true definition of ISO bring a shift in paradigm on ones photographic technique?

Maybe let's put it differently, when you look at a shot, how do you know the exposure is correct?

The same regardless of my understanding of ISO.

It appears that you may well have made Iliah's intended point beautifully. (My interpretation is that) his point is that without an awareness of, and control over, sensor-level Exposure when capturing a shot, there is no way (by simply viewing the image later) to determine whether the Signal/Noise Ratio could have been better by simply viewing the image after "brightening".

If that was his point the he's just skating around question. My question is in the context of photographic technique, not about how it looks later.

"Photographic technique" is only assessable by looking at the final results of all related efforts ...

So I ask again, maybe differently this time. How would knowing ISO was not part of exposure change my shooting technique?

Again, the point is to be aware of, and control, sensor-level Exposure to maximize Signal/Noise Ratio. Thinking about "ISO settings" is like fretting about the setting of an audio volume-control. It has nothing to do with the quality of the music produced - only its relative volume level.

Would I not make the same decisions regardless?

Not necessarily. That's just the point. If it did not affect your settings, it would mean nothing

Then give me an instance where it wouldn't. It's a simple request and everyone has evaded it including you. Give me a scenario where gaining the insight that "ISO was not part of exposure" has led one to a better (or even different) decision than a person less enlightened. Just one. Patiently waiting...

If image-sensor-level Exposure happens to (as it is) be maximized (the photosites are illuminated to their maximum possible illumination (with becoming non-linear in their response to the light) - then the highest possible Signal/Noise Ratio resulting from Photon Shot Noise is achieved.

The point of all this stuff is that unless the following technique is used (quoted from below):

Minimize F-Number and Shutter Speed as much as practicable (given desired DOF and camera/subject-stability). Select the ISO setting last (if recording JPGs or RAWs) ...

... then maximum sensor-level Exposure may not be achieved when recording an image.

Also quoted from below:

The improvement in SNR resulting from Photon Shot Noise will be proportional to the square-root of the ratio of the relative increase in sensor-level Exposure that you achieve.

I do not know if you may find this comprehensive text about these issues to be helpful or not:

http://theory.uchicago.edu/~ejm/pix/20d/tests/noise/

... but it is an excellent text that many of us have learned a great deal from.

I'd like to think it would improve technique, but I haven't seen evidence to support that. Perhaps discribe a scenario or post an example?

"Technique" is utterly subjective to evaluate. One person's "ceiling" may be another person's "floor". (I think) that you have missed Iliah's intended point (which is nothing new for him).

No, I got the point. He had missed mine (I think). Perhaps his silence is evidence that he got it now?

Iliah Borg does not say very much sometimes. He, as well as bobn2, are very knowledgeable.

Minimize F-Number and Shutter Speed as much as practicable (given desired DOF and camera/subject-stability). Select the ISO setting last (if recording JPGs or RAWs) - or even leave ISO at base setting (if recording RAWs) if you want to. Have a look for yourself at the differences. The improvement in SNR resulting from Photon Shot Noise will be proportional to the square-root of the ratio of the relative increase in sensor-level Exposure that you achieve.

 

[Andre Affleck]

Detail Man wrote:

Andre Affleck wrote:

Detail Man wrote:

Andre Affleck wrote:

Detail Man wrote:

Andre Affleck wrote:

Andre Affleck wrote:

Iliah Borg wrote:

If the incorrect information affects the shooting negatively it is a big issue.

Another example would be http://photographylife.com/what-is-iso-in-photography people get

So opening the proverbial can of worms again, does understanding the true definition of ISO bring a shift in paradigm on ones photographic technique?

Maybe let's put it differently, when you look at a shot, how do you know the exposure is correct?

The same regardless of my understanding of ISO.

It appears that you may well have made Iliah's intended point beautifully. (My interpretation is that) his point is that without an awareness of, and control over, sensor-level Exposure when capturing a shot, there is no way (by simply viewing the image later) to determine whether the Signal/Noise Ratio could have been better by simply viewing the image after "brightening".

If that was his point the he's just skating around question. My question is in the context of photographic technique, not about how it looks later.

"Photographic technique" is only assessable by looking at the final results of all related efforts ...

So I ask again, maybe differently this time. How would knowing ISO was not part of exposure change my shooting technique?

Again, the point is to be aware of, and control, sensor-level Exposure to maximize Signal/Noise Ratio. Thinking about "ISO settings" is like fretting about the setting of an audio volume-control. It has nothing to do with the quality of the music produced - only its relative volume level.

Would I not make the same decisions regardless?

Not necessarily. That's just the point. If it did not affect your settings, it would mean nothing

Then give me an instance where it wouldn't. It's a simple request and everyone has evaded it including you. Give me a scenario where gaining the insight that "ISO was not part of exposure" has led one to a better (or even different) decision than a person less enlightened. Just one. Patiently waiting...

If image-sensor-level Exposure happens to (as it is) be maximized (the photosites are illuminated to their maximum possible illumination (with becoming non-linear in their response to the light) - then the highest possible Signal/Noise Ratio resulting from Photon Shot Noise is achieved.

Sure but the person who believes that ISO is part of exposure also comes to that conclusion. Nice try though ;-)

See here...

pforsell basically said that here http://www.dpreview.com/forums/post/52214364

Funny. Back when I was dumb and happy, shooting my 20D, I too discovered this. Only I said it like this, "Using the same aperture and shutter, if I compare a correctly exposed shot at ISO3200 to one that was underexposed at ISO100 and pushed, the ISO3200 has lower noise."

Ironically, now that I am much wiser, I still shoot that way! Imagine that. Sure glad that I learned about that pesky exposure thing.

Still waiting...

The point of all this stuff is that unless the following technique is used (quoted from below):

Minimize F-Number and Shutter Speed as much as practicable (given desired DOF and camera/subject-stability). Select the ISO setting last (if recording JPGs or RAWs) ...

... then maximum sensor-level Exposure may not be achieved when recording an image.

Also quoted from below:

The improvement in SNR resulting from Photon Shot Noise will be proportional to the square-root of the ratio of the relative increase in sensor-level Exposure that you achieve.

I do not know if you may find this comprehensive text about these issues to be helpful or not:

http://theory.uchicago.edu/~ejm/pix/20d/tests/noise/

... but it is an excellent text that many of us have learned a great deal from.

I'd like to think it would improve technique, but I haven't seen evidence to support that. Perhaps discribe a scenario or post an example?

"Technique" is utterly subjective to evaluate. One person's "ceiling" may be another person's "floor". (I think) that you have missed Iliah's intended point (which is nothing new for him).

No, I got the point. He had missed mine (I think). Perhaps his silence is evidence that he got it now?

Iliah Borg does not say very much sometimes. He, as well as bobn2, are very knowledgeable.

I consider them, as yourself and a few others, the leading authorities on the subject. That's why I'm surprised about the lack in response.

Minimize F-Number and Shutter Speed as much as practicable (given desired DOF and camera/subject-stability). Select the ISO setting last (if recording JPGs or RAWs) - or even leave ISO at base setting (if recording RAWs) if you want to. Have a look for yourself at the differences. The improvement in SNR resulting from Photon Shot Noise will be proportional to the square-root of the ratio of the relative increase in sensor-level Exposure that you achieve.

 

[Glen Barrington]

Detail Man wrote:

It is really quite simple. The issue is the maximization of image SNRs due to Photon Shot Noise.

Ditch the "ISO" joke (which, in describing only one single point in a non-linear system's transfer-function, is an even crueler joke than 95% of folks even imagine), replace it with Scene Luminance in said "Holy Triangle", and the result is something that (actually) works in controlling and maximizing SNR due to Photon Shot Noise. The scaling of the image-sensor data (Image Brightness, and the entire concept of "ISO ratings" themselves) is absolutely meaningless outside of JPEGs encoded in sRGB color-space.

The "Exposure Triangle" is patently on its face pure misleading garbage, and the defensive, long-winded, and incredibly uninformed reactions exhibited by its "defenders" only serves to underscore the fact that as technology becomes more specialized, human curiosity and intellegence is devolving at ever increasing rates. The modern mind has become flaccid and docile - and the most troubling thing about the situation is how blind people are to their own ignorance.

People can talk all they want about what profound and deep knowledge that they (think) they learned in school - but if they cannot get their heads around something so relatievly simple and basic (and important) as sensor-level Exposure - then they might as well have not wasted their time with all the pomp and circumstance of sitting on their laurels holding a sheepskin diploma.

It has been shown that very few college graduates (in the US, anyway) after all their impressive sounding courses completed can even figure out how to hook up a light-bulb to a battery. I am beginning to get the feeling that such stellar brilliance is not limited only to the US.

That's fine. However, when people's technical knowledge is that limited, they should honestly admit it, and actually listen to (rather than defensively criticize) people as knowledgeable as the OP.

I have no idea what you are talking about, I feel like I stumbled into somebody else's argument. I was responding to a broader philosophical question.

 

[Iliah Borg]

Give me a scenario where gaining the insight that "ISO was not part of exposure" has led one to a better (or even different) decision than a person less enlightened.

I gave it recently. ISO speed bump clips the highlights. On the other hand the low brightness of an important part of a scene calls for an ISO bump if ISO is considered to be a part of something (anything). So in a scenario like a narrow alley in an old Italian town where the sky is bright and the walls on one side of the alley are very dark closer to the pavement it is worth to know that one does not need to bump the ISO speed.

And by the way, what ISO are we discussing, the red, green, or blue ISO? Daylight ISO or mercury vapor ISO?