N- and N+ Development Question

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Dismayed

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Sorry, did I forget to genuflect before criticizing Adams? I guess I should have said I assume Adam's wasn't very good at theory because of all the fundamental mistakes in his book.

I simply stated that I disagree with you. And you chose to be an asshole.
 
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I simply stated that I disagree with you. And you chose to be an asshole.
I was just trying to be funny (post #59), and apologized for not taking it more seriously (post #60). I believe my history on this forum shows that I'm willing to discuss issues. As I wrote, I think this is an important subject and worthy of discussion. If you are willing to make a case for your disagreement, we can begin.
 
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This is actually a very important subject and I shouldn't have been flip with my previous response. There are two issues here. Did Adams' books contain fundamental errors in photographic theory, especially tone reproduction, and exposure theory? What are the points of contention?

And secondly, could the reason many photographers regard Adams as the ultimate authority on photography is that they haven't had the opportunity or weren't aware of the more scientifically oriented photography books? I personally consider Adams' series as falling into the amateur / popular photography / how to milieu.

Stephen,

I agree that this is an important subject and would love to learn more from you. Unfortunately, rhetorical questions without follow-up explanations don't give me any information. So... What are your points of contention with Adams' Zone-System theory?

Best,

Doremus
 

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Flare is one problem.

The Ansel Adams Zone System film tests are performed in a way that there is no flare included in the exposure of the test film.

Then the interpretation is done in a way that flare should have been included in the computation, but it wasn't.

Take a look at silveror0's post #28 and my post #30.

We arrive at different development times for Normal, Normal + 1 and Normal - 1 ... from the same family test data.

That's because I am interpreting the results in a way that incorporates flare.
 

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An important point to bring up is that Ansel Adams worked hard to keep measures of contrast out of the Zone System.

In "Exposure Record," his definition of "Gamma" included his feelings...

"... it is difficult for the average photographer to evaluate and apply."
...
"I do not use the term Gamma in Zone System procedure; I believe it is unecessary and confusing with black and white photography."

Sometimes curve fitting can be hard, even with computers.

I have to admit, I never liked working with Gamma because it is difficult to measure.

But I find Contrast Index easy to use to measure contrast.

I absolutely love the Zone System notation when shooting and planning development. That is pure genius and timeless and practical.

But by ruling out the use of contrast measurement in the "lab," Ansel Adams made the test procedures more complicated than they need to be. Also it's awkward that the test results are valid only for a particular lens/shutter/paper, when those factors can be broken out easily enough.
 

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Last week I was lying on my back at lunchtime looking up at El Capitan. I decided to take that shot looking up and I was able to teach a bit of Zone System metering and previsualization to the group leader... without even taking a break from what I was doing because Zone System metering and previsualization is such a powerful, easy to explain and understand concept.
 
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Stephen,

I agree that this is an important subject and would love to learn more from you. Unfortunately, rhetorical questions without follow-up explanations don't give me any information. So... What are your points of contention with Adams' Zone-System theory?

Best,

Doremus
Doremus,

I was replying to Dismayed who disagreed with an earlier post but didn't include any reasoning to support his disagreement. This was my statement:

Adams in actuality wasn't very good at theory. The aims for NDR and Zone I are based on a misconception. Ever wonder why the LER for Grade 2 paper for a diffusion enlarger is 1.05 and Adams has a 1.15 - 1.25 for the NDR? Or how ZS film speed testing almost universally results in EIs 1/2 to one stop slower than the ISO speed?

So I included two examples of why I believe Adams isn't very good at theory. A critical review of The Negative should be encouraged.
 
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An important point to bring up is that Ansel Adams worked hard to keep measures of contrast out of the Zone System.

In "Exposure Record," his definition of "Gamma" included his feelings...

"... it is difficult for the average photographer to evaluate and apply."
...
"I do not use the term Gamma in Zone System procedure; I believe it is unecessary and confusing with black and white photography."

Sometimes curve fitting can be hard, even with computers.

I have to admit, I never liked working with Gamma because it is difficult to measure.

But I find Contrast Index easy to use to measure contrast.

I absolutely love the Zone System notation when shooting and planning development. That is pure genius and timeless and practical.

But by ruling out the use of contrast measurement in the "lab," Ansel Adams made the test procedures more complicated than they need to be. Also it's awkward that the test results are valid only for a particular lens/shutter/paper, when those factors can be broken out easily enough.

Bill, I find the conclusion to the Gamma quote from the first edition of The Negative, 1948 to be most interesting.

"Hence, is it not more logical to leave gamma to the sensitometrist and manufacturer, and to think of negative development in terms of a simpler symbol? X minutes at Y degrees temperature would represent “normal” with consideration for the photographer’s concept, lens, film, film developer, methods of printing and enlarging, and the paper used.

“7 minutes at 68 degrees F in Ansco 47 Isopan represents “normal” to me. I have no idea what the actual effective gamma is, nor do I care. I could consider this degree of development as yielding Gamma – 1.0 or being Development No. 9 or Operation H, or any other symbol I choose. But why should I inject an unnecessary and confusing symbol for a perfectly simple statement of procedure?"


I consider this to not only be a naive statement but erroneous. The particulars of any method of average gradient are communicated by the name of the method. By writing Gamma or CI or G bar in front of a number, it is informing the reader of how the film was tested. The results can then be evaluated based on the known strengths and weaknesses of the method. A statement about processing for X minutes at Y degrees gives little relevant information. If someone tells me the film was developed to a CI 0.58. I know how much contrast the film has, how it should print for a given luminance range and on what grade of paper, and am able to reproduce the results myself with any film / developer combination. If someone tells me they developed a film for 7 minutes at 68 degrees. I only know those two pieces of information.

Attempting to incorporate the camera isn't more logical. Too many variables are included that will confuse the results of a film test. Factoring in the methods of printing and paper used are important to determining degree of development. They should be a know and generally included with the definition of Normal, +1, etc. And while Adams states it's important, he doesn't actually give a explanation of paper testing and how it calculates into the determination of development. What most people are familiar with is a table of the aim negative density ranges for a diffusion and condenser enlarger that are towards the back of the later editions. The table doesn't adequately explain how the numbers are derived.
 
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I should add some info to my post #28 as regards reduction of flare:

1) The camera used was actually a Sinar 5x7 with a 4x5 back to keep the camera bellows farther from the film during exposure in an effort to minimize the bellows' contribution to flare.

2) The lens used was a Symmar that's not multi-coated and its inherent flare characteristics are therefore included in the test results (none of my lenses are multi-coated); its actual shutter speeds are known and accounted for. If I knew how to go about confirming the accuracy of my apertures I would have done that as well, but I do have a habit of changing apertures by moving in the "closing down" direction (recommended by AA) to rule out free-play in the aperture mechanism.

3) Admittedly the use of a white mount board as a target should cause more flare than a darker board, so that’s why I chose to use a bellows shade that masked the film format as closely as possible, then metered the target using an SEI photometer with its anti-flare tube attached (the meter, incidentally, was checked for agreement with my Gossen meter recently re-calibrated by Quality Light Metric).

My point in all this is that the test results calibrate MY equipment and MY workflow and agitation technique to work as MY system.

In post #28 you wrote, "All tests were done by taping a Stouffer 21-step wedge to the sheet of film in its holder." The step tablet was contacted. There is no flare. Camera flare is irrelevant to this test. What you did with the bellows isn't a factor. Please understand that I am not attacking your technique, but only using this one example to make a point. What assumptions do we make with testing and how do they influence the interpretation of the results? How do we know the testing results are legitimate or if they just happen to fall under the tolerances of the process? How necessary is testing if the answer is most likely the latter? Proper interpretation of good data is critical for any results to be relevant. So what's worse, bad testing or no testing at all?
 

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I should add some info to my post #28 as regards reduction of flare:

1) The camera ...

2) The lens ...

3) ... the use of a white mount board as a target...

Your test is a good one. Non-Flare tests are good.

As Stephen pointed out, taping the step wedge in contact with film eliminated flare.

There are some other common tests...

In a flat tone test, flare does not exist when the subject luminance ratio is 1:1, which would be the ratio when you shoot a single tone test target.

In a flat tone test, people reduce the light hitting the film by increasing the shutter speed and/or closing down the lens aperture. What little percent of flare exists will only add a small percentage of light to what is already a greatly reduced amount of light.

There is one other kind of film test which does have flare and where flare adds exposure to the shadows.

The kind of test where you tape a step wedge to a window, and mask off the extraneous edges carefully, and shoot with camera... That kind of test will have flare.

Here you have a clear step that allows nearly 100% of the light through, a few percent of that will hit the entire sheet of film. Under the 2.0 step you would want to have only 1 percent of light strike the film, but a few percent already hits it from the light reflecting off the bright step and bouncing around inside the camera.

silveror0, You did a contact test... light can't sneak around and get under the 2.0 step, so you really do hit that film with 1% of the light that hit the top of the step wedge.
 

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Bill, I find the conclusion to the Gamma quote from the first edition of The Negative, 1948 to be most interesting.

"Hence, is it not more logical to leave gamma to the sensitometrist and manufacturer, and to think of negative development in terms of a simpler symbol? X minutes at Y degrees temperature would represent “normal” with consideration for the photographer’s concept, lens, film, film developer, methods of printing and enlarging, and the paper used.

“7 minutes at 68 degrees F in Ansco 47 Isopan represents “normal” to me.
.

Here Ansel Adams does not even realize the pure beauty of the Zone System he created.

It is the N notation, not the "number of minutes in the developer that equates to Normal", that was his genius idea.

In abstract terms, Normal is the extent of film development that fits a normal subject luminance range to a normal grade of paper.

Normal plus 1 is a longer extent of development that expands "one less stop than normal" of subject luminance range to fit the same paper.

Normal minus 1 is a shorter extent of development that contracts so that "one more stop than normal" fits...

While I don't find where he concretely defined how many stops he means when he is talking "Normal", I may choose a sensible number of stops as Normal, suppose I call 7 stops subject luminance range Normal. It might be Zone I to Zone VIII.
 

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"Hence, is it not more logical to leave gamma to the sensitometrist and manufacturer, and to think of negative development in terms of a simpler symbol?..

But why should I inject an unnecessary and confusing symbol for a perfectly simple..?"

Here he started to say it... but didn't finish the abstraction

N, N-1, N+1

Purely simple and abstract and easy to grasp and implement.
 

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Is that what we want?

Depends of course. All week in Yosemite, I found mostly normal and flat lighting, N to N+2

But I did have one shot of Half Dome with banks of Merced at 5:45am where clouds metered 15 and fell on Zone XI and foreground trees metered 6 placed on Zone II

I noted EI 400 and gave exposure 1/4 second at f/22

Do I want to develop it N and sacrifice clouds? Or develop it at N-1 and hold some detail I might be able to reveal with a bit of burning?

I think I'll develop it N-1
 

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You're still thinking like Ansel. If you develop your 5:45am shot N, are you sacrificing the clouds? (hint: answer is no).

What if developing N- actually sacrifices some detail?

Let me think about that a minute.

I placed my shadow on Zone II. By using EI 400, I effectively placed them on Zone I. The clouds on Zone XI may have come to Zone X by dint of the EI 400 rating. And that may be where I want them to be.

Since I consider my spotmeter to preview flare, I could say that Zone I is where the shadows will fall including flare. Developing N-1 would bring the density of 0.10 if that's what I was getting, to 0.06

Cloud density on negative if developed to N-1 would be 1.5 vs cloud density 1.9 developed to N.

Are you sure I'm not going to lose my clouds developing to Normal?
 

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This shot I described is a good example of the problem.

The foreground, early morning is very flat. If I develop N+1 it would make the foreground more interesting. N-1 is likely to make it dull and lifeless.

So maybe I'll bring Half Dome up to Zone VII and VIII and gain contrast in the river. Forget the clouds, and sort of forget Half Dome too. I could leave that landmark barely recognizable so it merely hints at the location of the scene.
 

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This shot I described is a good example of the problem.

The foreground, early morning is very flat. If I develop N+1 it would make the foreground more interesting. N-1 is likely to make it dull and lifeless.

So maybe I'll bring Half Dome up to Zone VII and VIII and gain contrast in the river. Forget the clouds, and sort of forget Half Dome too. I could leave that landmark barely recognizable so it merely hints at the location of the scene.
Or burn in the clouds?
 
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Okay, the curves in the below example are from The Negative. The curve for Normal has the negative density range (NDR) for Zone I to Zone VIII as 1.25, which correlates with the table of aim negative density ranges. Grade 2 papers have an average LER of 1.05 which means the NDR should be 1.05 for the negative to fit the paper printing with a diffusion enlarger. 1.25 is obviously too large. Film curves are created in a flare free environment. Flare for the average luminance range is around 1 stop. That means the 7 stop luminance range will be a 6 stop illuminance range at the film plane. So, we need to measure the range not to Zone VIII, but to Zone VII. This gives us a NDR of 1.05 which will fit the grade two paper.

If Adams adjusted the aim NDR in his book to compensate for a flare free test, he never stated it and there's no indication he ever though about it.

The Negative Film Curve.jpg
 
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Bill Burk

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You know I always consider the shift for flare to come from the shadow, so by my reckoning Zone I comes up to Zone II and the density of Zone VIII remains 1.25 - still produces a negative with DR 1.05 for Normal.

Now in my example where I changed EI to 400, for my shot of Half Dome and Merced River, I created a negative which was exposed much like your sketch (except my clouds on Zone XI will come down to Zone X because I changed EI and I will have a Negative Density of 1.9 on my curves if I develop to my N).

I will have a density 0.4 more in the clouds to burn (thus 1 1/3 stop of burning. On a 32 second base print exposure that means over a minute of burn time more than an N-1 negative). I don't think I would enjoy printing that negative. Even with N-1 I will get 1.5 density clouds and that is going to be paper white.

Still I argue this negative may be best developed to N+1 - because the flat morning light will give me no sparkling water. I metered 9 on water and placed on Zone V. 10 and 9 on the granite of Half Dome which I placed on Zone VI and Zone V respectively. The water and dark granite of Half Dome would look good printed to Zone VI and the light granite of Half Dome would print on Zone VII which will hold detail.

I'm thinking that I will sacrifice the clouds though since they will hit somewhere around Negative Density of 2.3 which would be silly to try to print.
 
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You know I always consider the shift for flare to come from the shadow, so by my reckoning Zone I comes up to Zone II and the density of Zone VIII remains 1.25 - still produces a negative with DR 1.05 for Normal.

Now in my example where I changed EI to 400, for my shot of Half Dome and Merced River, I created a negative which was exposed much like your sketch (except my clouds on Zone XI will come down to Zone X because I changed EI and I will have a Negative Density of 1.9 on my curves if I develop to my N).

I will have a density 0.4 more in the clouds to burn (thus 1 1/3 stop of burning. On a 32 second base print exposure that means over a minute of burn time more than an N-1 negative). I don't think I would enjoy printing that negative. Even with N-1 I will get 1.5 density clouds and that is going to be paper white.

Still I argue this negative may be best developed to N+1 - because the flat morning light will give me no sparkling water. I metered 9 on water and placed on Zone V. 10 and 9 on the granite of Half Dome which I placed on Zone VI and Zone V respectively. The water and dark granite of Half Dome would look good printed to Zone VI and the light granite of Half Dome would print on Zone VII which will hold detail.

I'm thinking that I will sacrifice the clouds though since they will hit somewhere around Negative Density of 2.3 which would be silly to try to print.

Bill, it's just a way to measure. It's not supposed to be a model of how flare works. Flare reduces the range by one stop. Take off one stop. What is the NDR for a 6 stop range?
 
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Bill, there's another way to look at measuring the exposure range. With correct ISO exposure, the shadow will fall approximately one stop below the fixed density of 0.10 over Fb+f. Flare will bring it up to around 0.10. So the highlight should then fall Δ1.90 log-H to the right. Only with the Zone System EI with the 2/3 to 1 stop overexposure does the flare fall where you are referring to and the highlight density would be what it would be at Zone VIII. Otherwise with correct exposure, it will fall at what is considered Zone VII density.

Speed Point - Metered Exposure Ratio - Zone System apug.jpg
 

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Bill, there's another way to look at measuring the exposure range. With correct ISO exposure, the shadow will fall approximately one stop below the fixed density of 0.10 over Fb+f. Flare will bring it up to around 0.10. So the highlight should then fall Δ1.90 log-H to the right. Only with the Zone System EI with the 2/3 to 1 stop overexposure does the flare fall where you are referring to and the highlight density would be what it would be at Zone VIII. Otherwise with correct exposure, it will fall at what is considered Zone VII density.

I came close to what you are describing, ISO exposure, by setting my meter at 400. So for what I did (your post 84) graph is right (I get different specific densities because I use my graphs).

I keep hearing you say... do you know what you're getting? That's why I point out what I think would be a better model for Zone System usual practice. (Your post 88 graph looks good)
 
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I came close to what you are describing, ISO exposure, by setting my meter at 400. So for what I did your graph is right (I get different specific densities because I use my graphs).

I keep hearing you say... do you know what you're getting? That's why I point out what I think would be a better model for Zone System usual practice.

There's also how the Zone System range is suppose to theoretically start at Zone I.
 
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