Zone System - Find EI and dev time without resorting to sensitometry

[Stephen Benskin]

"The Zone System is a practical expression of sensitometry, the science that relates exposure and density in photography. If the Zone System is understood, the underlying sensitometric principles should not be difficult to grasp and can provide much information useful to the photographer." - Ansel Adams, The Negative, p. 84-85.

 

[Photo Engineer]

Daan Zwick used to say "we sell photos not curves"!

Yet, all this seems to center on curves.

PE

 

[RobC]

Yes Ron, but once one decides to use any kind of "system" (ZS, BTZS, etc.), regardless of how technical or non-technical they try to be, they are stuck with curves since curves are the underlying system. You once said it yourself: "The Zone System is just a H&D curve".

No, some people have a completely different mindset and just think of contrast, pushing and pulling. Probably don't even know what a curve is. If they haven't read Adams anything he said is irrelevant to them.

 

[David Allen]

Just to remind everyone, the OP's question was "Zone System - Find EI and dev time without resorting to densitometry" so all of this curve talk is irrelevant. Lets just say, try my tests and you will not need a densitometer (and you will get, very quickly, the answers that you need).

Bests,

David.
www.dsallen.de

 

[pdeeh]

Or, as a real technical authority has already said, shoot at box and develop in a standard developer for the manufacturer's recommended time ... :sly:

 

[David Allen]

Oh I have just remembered a gem of an explanation that I received at age 18. I was on the part-time Professional Qualifying Exam course of the Institute of Industrial Photographers at the Polytechnic of Central London (the course ended up being changed to a BA in my last year). I was, literally, the last class that received sensitometry training from Frank. He was a trained industrial photographer who bought his house through the selling of ice used to cool developers to Arabs during the Eighth Army's campaign in Africa. He knew Dunn and Wakefield well and liked to pontificate about technical matters.

His great comment to me was that Ansel Adams had absolutely no idea about densitometry and that his ideas were 'rubbish'. He then commended favourably on my work on grounds of technical excellence (I was at the time using a plate camera in full Zone System mode) and then came the great explanation and I quote from memory "Ansel Adams is an idiot who does not understand even the basics of sensitometry. However, I do like his pictures even though they are clearly way different from 'real' tonal reproductions of a scene.

That's it for me, bugger the technical 'correct' rendering of a scene, I want my photos to look how I want them to look. That is why I am totally opposed to the rhetoric of 'use the manufacturers ISO and development times'. This is indeed fine if you want to reproduce a scene how the manufacturers intended but that is not what I want.

Bests,

David.
www.dsallen.de

 

[Stephen Benskin]

I can see testing without a densitometer, but using Zone terminology is just another way to express tone reproduction. 1 Zone = 0.30. Same thing. It's counter productive to arbitarily place limits on the terms people can use to express ideas. Oh, the OP brought up the Zone System negative density range of 1.30.

 

[pdeeh]

I am totally opposed to the rhetoric of 'use the manufacturers ISO and development times'. This is indeed fine if you want to reproduce a scene how the manufacturers intended but that is not what wantl]

That's either a bizarre use of the word "rhetoric", or simply bizarre.

What does the manufacturer of the film and developer I will use tomorrow think the photograph I might take tomorrow ought to look like?

Normally your posts make quite a lot of sense, David, and are helpful and useful... but on this occasion you seem to have let your personal theories about film testing get in the way of rational discussion

 

[Stephen Benskin]

That's either a bizarre use of the word "rhetoric", or simply bizarre.

What does the manufacturer of the film and developer I will use tomorrow think the photograph I might take tomorrow ought to look like?

Normally your posts make quite a lot of sense, David, and are helpful and useful... but on this occasion you seem to have let your personal theories about film testing get in the way of rational discussion

The same can be said about this whole thread. I'm thinking about to starting a thread where people can't use pronouns.

 

[pdeeh]

No good for me Stephen, I have no idea what a pronoun is.

 

[Photo Engineer]

David, your post #89 was very much to the point of a lot of my training.

Now, as for manufacturers guessing what you want, remember that they employ a lot of world class photographers to use their products and to give them advice. Even now, several are APUG members. They don't use the zone system or densitometry. They do use densitometry to back up good pictorial results with data.

And if you suggest that there are no great photographers on Kodak staff, remember that once a member of the staff, they are no longer allowed to compete or show photos outside of EK. EK had a yearly in-house competition for these people and the photos were outstanding. I remind you that the Colorama photos were often taken by in-house photographers. See here: http://library.rit.edu/findingaids/html/RITArt.0087.html

Sam has copies for sale if you want one!

He is just one of many who tested products before and during sale.

PE

 

[Nodda Duma]

Tag for later reading

 

[Xmas]

The same can be said about this whole thread. I'm thinking about to starting a thread where people can't use pronouns.

Be simpler getting a mod to alter the probity filter to map zone to manure.

 

[David Allen]

That's either a bizarre use of the word "rhetoric", or simply bizarre.

What does the manufacturer of the film and developer I will use tomorrow think the photograph I might take tomorrow ought to look like?

Normally your posts make quite a lot of sense, David, and are helpful and useful... but on this occasion you seem to have let your personal theories about film testing get in the way of rational discussion

I was using rhetoric in the sense of one of it’s meanings which is where language is designed to have a persuasive or impressive effect. In this specific case, suggesting that the manufacturers ISO and development times are the best and so should work for you.

However, if someone asks in a thread for advice about finding a personal EI and development time without using a densitometer, it is clear that they have tried the manufacturer’s recommendations and are unhappy with the results. To advise the Op to “shoot at box and develop in a standard developer for the manufacturer's recommended time” is rhetoric in this case as the advice is seeking to persuade someone to do what may work for others but clearly does not work for the OP.

As to “This is indeed fine if you want to reproduce a scene how the manufacturers intended but that is not what I want” - I am sorry if this is not clear enough. It does not imply “What does the manufacturer of the film and developer I will use tomorrow think the photograph I might take tomorrow ought to look like?” but rather how a particular film, EI and development combination has been formulated to work by a manufacturer may well not be what you want when making photographs.

To clear this up, the manufacturers have invested a lot of time, personnel and money developing their products. These are tested to ISO standards and by photographers to ensure that the products work reliably and produce consistent results. They are also in competition with other manufacturers and need to present their products as equal or better. So if the ISO standard says that a film can be promoted as having an ISO of 400 that is how it will be marketed.

Whether said film rated at ISO 400 and developed for the manufacturer’s recommended time produces the results that you as a photographer wants is quite another matter. This will depend upon your views on what balance you want to achieve in terms of sharpness, levels of grain, acutance, speed of film that you require to make your images, subject brightness range, contrast in the final print and tonality. The manufacturer’s recommendations will produce one (of many possible) compromises between all of these variables and this is what I meant by “This is indeed fine if you want to reproduce a scene how the manufacturers intended”. However, if shadow detail is more important to your way of working you are going to have to move away from the manufacturer’s recommendations.



In my case, I use Delta 400 rated at 200 and developed in a two-bath developer. I meter the darkest shadow where I wish to retain detail and place on Zone III. In the case of the photograph above, the shadow area on the right underneath the top of the wall read 9 on the Weston meter and the brightest highlights fell on 15 (meaning they fell on Zone IX). The options for this scene were:

• Expose at 200, place shadow on Zone III and use minus one development with a standard developer.
• Expose at 200, place shadow on Zone III and use a two-bath developer (my preferred way of working)
• Expose at 200, place shadow on Zone III and use some form of water bath or stand development

Other possibilities would be:

• Use the manufacturer’s recommended ISO of 400 and process for recommend time which would result in too little retained shadow detail for my preference (and potentially a little bit too much contrast).
• Use the ‘Sunny 16 rule’ with an ISO of 400 - which would result in 4 stops less exposure than required to retain the shadow detail
• Use the ‘Sunny 16 rule’ with an ISO of 200 - which would result in 3 stops less exposure than required to retain the shadow detail

Hope that clarifies everything.

Bests,

David.
www.dsallen.de

 

[removed account4]

No, some people have a completely different mindset and just think of contrast, pushing and pulling. Probably don't even know what a curve is. If they haven't read Adams anything he said is irrelevant to them.

been making photographs ( negatives and prints ) for a long time
sometimes process and print other people's work in addition to my own ...
no idea how to even read a curve, just as you said ...
i can understand others rely on them but i don't ...
not because it stifles creativity or turns people who
uses them into this or that but because i never found the need
to use / study ( or maybe be devoured by ) them .
( just like i don't have the need to measure out my ingredients when i make dceffenol developer
but that's another thread )

of course YMMV

 

[rbultman]

David, this part of the problem. It is an unlikely scenario. It is much more probable the person has read something about EIs or "real" speeds or the Zone System or whatever, and has decided at the outset to find an EI which is better than the ISO speed.

This is where I am, I've read about it. My negs seem to be ok for the most part with a few being problematic WRT printing. It's the reading that is driving me to look at developing an EI, not because I have huge problems.

Your test methodology is as good as any other no-flare/low flare model (although "minimum time to max black" can be problematic), but ultimately is subject to the same shot-to-shot variables as ISO or any system.

Bill makes this point in his article. Pick a system and stick to it, at least initially.

More questions: In the context of current long scale films and VC papers, is the Zone System still relevant? Do we have the control we think we have over our negatives? I've tried to test quite a few of these controls and the results were sobering.

I've had the same question regarding VC papers. I think the ZS still applies even with VC papers. Expose for what you want to emphasize and develop to try to match the equivalent of grade 2 and filter as needed for more or less contrast. Split grade/filter printing with VC papers gives even more leeway.

Michael, can you please describe some of your tests and the results?

Regards,
Rob

 

[Sirius Glass]

I shoot at box speed. When I use the Zone System I set the Gossen Luna Pro SBC to the zone [Zone 4] of the part of the subject that I will set that zone [for example an area I want to be in Zone 4] and take the light reading. I use that light reading for the camera setting. That is pretty simple.

 

[RalphLambrecht]

David, this part of the problem. It is an unlikely scenario. It is much more probable the person has read something about EIs or "real" speeds or the Zone System or whatever, and has decided at the outset to find an EI which is better than the ISO speed. That's the legacy of the Zone System - ie the presumption, before even shooting one picture, that we should do a test which will somehow reveal a personal EI.

In reality, there is nothing really "personal" about it, and no mystery behind it. Why does everyone's "personal" Zone System EI end up the same (1/2 to 1 stop lower than ISO speed)? Because in a Zone System test you look for the speed point 2/3 stop lower than in the ISO model. That's about all there is to it from a practical testing perspective. Not only do you not need a densitometer, you don't need need a test. Just down rate the film by a stop.

Regarding manufacturers knowing or not knowing how I want to shoot, I think that is another Zone System red herring, particularly in the context of current materials. It also works under the misguided assumption regarding the level of precision we can achieve. There is nothing to be gained by calibrating an EI to 1/3 stop precision.

Your test methodology is as good as any other no-flare/low flare model (although "minimum time to max black" can be problematic), but ultimately is subject to the same shot-to-shot variables as ISO or any system. I'm not saying it is wrong and I'm not advocating against it. What Stephen is trying to get us all to understand is simply that we should be aware of what these tests are or aren't telling us.

Here's another thought. Why don't we just dispense with EIs, use the ISO speed and simply place values one Zone higher? It's all arbitrary anyway, so why not?

A thought regarding Adams (who I admire greatly): Most of his famous images are from negatives made before the Zone System, negatives he messed up on etc. Read his stuff carefully and it is mostly about latitude, and we have quite a bit more flexibility at our disposal than he did.

More questions: In the context of current long scale films and VC papers, is the Zone System still relevant? Do we have the control we think we have over our negatives? I've tried to test quite a few of these controls and the results were sobering.

I'm a big fan of the Zone System and all the testing but I agree with Michael's conclusions too.He obviously understands his materials and that is the one thing Zone System testing and the densitometer really did for me.We all learn in different ways,quantittive test results is the best road to understanding for me.Hoeever, at the end of the day,one has to review the test data and put it all into practical terms.No need to expose and develop to 1/6 stop(and yes,I can do that)if you have trouble recognizing 1/3 stop difference in the print(and many of us do).Keep it simple,AA did and then D&Bed the heck out of it to model the print.

Thank God for VCpaper.

 

[RobC]

What the zone system does is to give you control. What that level of control is depends on your ability to calibrate accurately. Most people only attempt to work out a personal film speed ( EI ). But they don't calibrate development time. Adams for all his writings shows in his charts and curves that that he was actually calibrating to an 8 stop range and not 10 (this assumes that paper in his day responded in same way as current papers). So was he being a naughty boy or did he not understand his own numbers or did he just like the results he got by using his own values and assume it must be correct? I have no idea which but if you use his numbers you will get essentially what Micahel is saying.

However, since everyone thinks but never tests that a 10 stop range actually fits grade 2 they never get what they think they will get and that will lead to claims of zone system inaccuracy or being wrong. It is and it isn't depending on how you go about it.

So how many of you have actually reproduced that zone patch test as I suggested. I suspect very few if any and those that have, probably found it doesn't give them what they expected. To then say there is no accuracy in the zone system is garbage. The fact is that if it doesn't give you the patches as shown in his book then YOU HAVE NOT CALIBRATED PROPERLY according to what the zone system says. Don't blame the zone system for that.

So off you all toddle and test if you are using the zone system or not. You do that by doing the test in 1st post of this topic. If it produces the correct result then you are using the zone system. If doesn't then you aren't, you just think you are. So no further need of argument or discussion because you can all validate your own claims and assertions by doing the test. Anyone whose test doesn't produce the correct result can keep it to themselves but should feel a great deal of shame about getting it wrong considering their assertions being made here.

My bet is nobody will do it. Well before you tell me you know best or ask why should you, I should say its not compulsory but as long we're all arguing when we're all using different testing regimes, then we're never going to agree on anything. Until everyone can produce the same result from the same test it means some are not capable of doing it with any accuracy. The proof of the pudding is in the eating. If you can't produce the correct result then ask yourself why not. Assuming your equipment is not faulty then it will be YOU that can't do it right. That will be very educational for all those who try it. It's a simple enough test if you can be arsed to do it.

 

[Stephen Benskin]

David, this part of the problem. It is an unlikely scenario. It is much more probable the person has read something about EIs or "real" speeds or the Zone System or whatever, and has decided at the outset to find an EI which is better than the ISO speed. That's the legacy of the Zone System - ie the presumption, before even shooting one picture, that we should do a test which will somehow reveal a personal EI.

In reality, there is nothing really "personal" about it, and no mystery behind it. Why does everyone's "personal" Zone System EI end up the same (1/2 to 1 stop lower than ISO speed)? Because in a Zone System test you look for the speed point 2/3 stop lower than in the ISO model. That's about all there is to it from a practical testing perspective. Not only do you not need a densitometer, you don't need need a test. Just down rate the film by a stop.

Regarding manufacturers knowing or not knowing how I want to shoot, I think that is another Zone System red herring, particularly in the context of current materials. It also works under the misguided assumption regarding the level of precision we can achieve. There is nothing to be gained by calibrating an EI to 1/3 stop precision.

Your test methodology is as good as any other no-flare/low flare model (although "minimum time to max black" can be problematic), but ultimately is subject to the same shot-to-shot variables as ISO or any system. I'm not saying it is wrong and I'm not advocating against it. What Stephen is trying to get us all to understand is simply that we should be aware of what these tests are or aren't telling us.

Here's another thought. Why don't we just dispense with EIs, use the ISO speed and simply place values one Zone higher? It's all arbitrary anyway, so why not?

A thought regarding Adams (who I admire greatly): Most of his famous images are from negatives made before the Zone System, negatives he messed up on etc. Read his stuff carefully and it is mostly about latitude, and we have quite a bit more flexibility at our disposal than he did.

More questions: In the context of current long scale films and VC papers, is the Zone System still relevant? Do we have the control we think we have over our negatives? I've tried to test quite a few of these controls and the results were sobering.

Michael, I'd just like to add that sensitometry, like all science, is a diagnostic tool to examine and explain phenomena. You don't have to do sensitometric testing to use tone reproduction theory to examine a process. We know that the Zone System will produce consistently lower EIs because it has different testing parameters than the ISO method, and we can know that because we understand the process through knowledge of sensitometric principles. And we can illustrate it and communicate it to others through the language of sensitometry.

Do people generally find their EIs 2/3 (+-1/3) stop lower than the ISO rating? They do. This is a strong indication our theory is correct. Where did the theory come from? Working out the steps and figuring out the differences. ZS starts at the metered reading and stops down 4 stops. That's a difference of 1.20 log-H. No curves or densitometers used. The ISO speed point is at a fixed density of 0.10 and uses the equation of 0.80/Hm. The equation used for the metered exposure point is 8/Hg. Let's use 125 speed for example. 0.80/125 = 0.0064, 8/125 = 0.064. That's a 1.0 log-H difference or 3 1/3 stops. The difference between the resulting Zone System speeds and the ISO speeds, all things being equal, is 2/3rds of a stop. Determined through simple reasoning. Even better, this can be illustrated using pictures or curves.

Sensitometric principles can be used to evaluate what a process is actually doing or if there are potential flaws or unconsidered variables involved. We know that the rate of a falling object is 32 ft/s2. If a dropped object takes longer than calculated then other forces must be at work, like air resistance. If somebody didn't know gravity was a constant, they could easily come to a different conclusion as to why the feather took longer to fall than the rock. Aristotle sure did.

The argument against manufacturers testing under control conditions comes from not understanding the scientific process. Lyod Jones did psychophysical testing to determine film speed, paper grades, and most of the concepts of tone reproduction like matching the scene through the negative and reproducing it on a print. You could say everything was reverse engineered. Images were shot and printed. People then judged what was good. Jones and his people then looked at the sensitometric data from the negatives and prints that produced the prints judged as having the highest quality. He then try multiple testing methods to determine which method would produce the same results from the judged prints (judged print speeds) over the widest range of film types and shooting conditions. So even though the tests are done in the lab (in order to be consistent and eliminate unwanted variables), the results are linked to usage.

As for people unhappy with the ISO speeds. The most likely explanation is from how they use their equipment or from personal taste (this includes how the print looks to them). If one test generally produces a consistent result relative to another test (in this case the ISO speed), why retest? Not happy with the results using the ISO setting, use the ISO as a base and go from there. Read the ISO speed, open up 2/3rds of a stop and Bobs your uncle. The claim that ZS testing incorporates your equipment, etc is mostly rubbish if you break it down. You'd have to a test for every lens you own, at every shutter speed, at every f/stop? There are a bunch of other variables that aren't even considered most of the time? If a person is concerned about their equipment, including meter calibration. Get it checked. Then if necessary factor in those results. If want to know the film speed, test for just the film speed.

Truthfully, I suspect the emphasis placed on the importance of ZS film speed checking is because you can't determine the film's contrast without it. Another shortcoming?

Finally, art is a combination of craft and expression. Anyone who argues differently is being disingenuous.

 

[Stephen Benskin]

However, since everyone thinks but never tests that a 10 stop range actually fits grade 2 they never get what they think they will get and that will lead to claims of zone system inaccuracy or being wrong. It is and it isn't depending on how you go about it.

A ten stop range isn't considered normal, so it won't fit on a grade 2 paper if it is developed to what is considered normal contrast. Don't know where the assumption that normal luminance range is 10 stops comes from. It might be coming from the print having 10 print zones. I've already approached this question in two different ways, posts 77 & 82. To summarize, the basic scene luminance range is 7 1/3 stops.



The range is based on the deepest shadow in which detail is visible and the brightest diffuse highlights. The normal range is from a 100% relative reflectance to 0.63% relative reflectance. Accent black and specular reflections are not part of the calculation.

The idea is to fit the NDR of the film onto the paper. The paper's log exposure range is determined from two points that aren't at the paper's D-max or D-min. The idea is to place the deepest shadow in which detail is visible and the brightest diffuse highlights within these two points. The more extreme values will fall outside this range. You do not want to place accent shadow or specular reflections within these two points.

If the scene has a greater luminance range than 7 1/3 stops, then the development needs to be adjusted in order for the negative to fit on a grade 2 paper or a different paper grade is required.

There is an equation: Aim Paper LER (also NDR) / (log subject luminance range - flare) = aim contrast index. Kodak uses an CI of 0.58 for Normal. They consider the LER for a grade 2 paper to be 1.05 and flare to equal 0.40. The average subject luminance range is then (NDR + CI*Flare) / CI = LSLR or (1.05 = (.58*.40)) / .58 = 2.20 or 7 1/3 stops.

A ten stop scene luminance range would require a CI of 0.43 (flare generally increases 1/3 stop per stop luminance range). Using a a fixed flare value of 0.40 would result in a CI of 0.40.

What would be the resulting NDR if a 10 stop subject luminance range was processed at a normal CI of 0.58? 1.51 What paper grade would that most likely fit on?

 

[RobC]

yes it gives massive control so that printing becomes easy and not a rescue job.

It gives the control to put the exposure on the film where printing becomes much easier. As I outlined, if you expose for a highlight then you always place your highlights on a consistent highlight density. This allows increasing print contrast to get shadow densities where you want them without danger of blocking them. And without the need to reduce print time. This means you can get the optimum print time to get good blacks and good highlights very easily.

My L1200 enlarger out of the box has a contrast speed point on a middle grey. Ilford filters have a speed point on a highlight. I have never seen any filtration system which has its speed point on a shadow value. The usual advice is work out print time for a highlight and adjust contrast to get your shadows correct. Well this is nonsense if your filters speed point isn't in a highlight. What I suggest is that matching your film exposure to put it on the optimum density to match your filters speed point will make printing much much easier and allow you to concentrate on making a fine print instead of rescuing a negative with poor exposure.

If you expose for the shadows and SBR is only say 6 stops then you really need to adjust print time to suit the shadows and adjust contrast to suit the highlights. Well that will be a real PITA if your filter speed point is in the middle or a highlight because you will be having to adjust print time a lot more with a change in contrast than you would if your filters and film exposure are matched.

Importantly I am basing all of this on roll film usage not sheet film where you can do what you want. AND its based on the fact that we know Ilford filters are highlight speed matched. Your own enlarger may or may not be speed matched on any density so using Ilford filters takes the uncertainity out of the equation unless you want the hassle of trying to work out your own Y+M filter values which is another exercise in time wasting.

Again, if your SBR is greater than 10 stops then resort to exposing for the shadows just to get them on fllm but expect to do a rescue job in printing.

I think most people find it easier to work up to required print contrast rather than work down which is why I don't favour your "use manufacturers film dev time" approach. However this is really dependant on the type of subjects you typically make images of. If they are landscapes which tend to have higher SBR then I would certainly not use your approach. But if they were closed scenes without bright skies and lower SBR then maybe I might think about it. But I say my approach works for both whereas your approach will make printing high SBR subjects (upto 10 stops (and more) ) more difficult, you will need to work down to required contrast.

The ideal subject would probably have an SBR of around 5 stops. But they don't, they are usually all over the place and not ****** "normal".

Just my opinion. YMMV as usual..

 

[markbarendt]

If you expose for the shadows and SBR is only say 6 stops then you really need to adjust print time to suit the shadows and adjust contrast to suit the highlights. Well that will be a real PITA if your filter speed point is in the middle or a highlight because you will be having to adjust print time a lot more with a change in contrast than you would if your filters and film exposure are matched.

Well, what you're saying may be absolutely true for you, but it is still a conditional statement based on your preferences and subject matter.

There are a few of us that peg to mid-tones and high tones as a matter of course though because it's an easier way to get the print we want. This is typically driven by photos that include, among other things, faces. This group includes movie studios, portrait and wedding photographers, grand parents, and a few others like color film shooters.

 

[Photo Engineer]

Rob, with such "fine" control of your negatives and prints, I would think that you would have posted at least one of these "prize winners"!

The majority of the rest of us have anted up! Come join us.

PE

 

[RobC]

Well, what you're saying may be absolutely true for you, but it is still a conditional statement based on your preferences and subject matter.

There are a few of us that peg to mid-tones and high tones as a matter of course though because it's an easier way to get the print we want. This is typically driven by photos that include, among other things, faces. This group includes movie studios, portrait and wedding photographers, grand parents, and a few others like color film shooters.

I think there have been quite a few people long before I formed my opinions that came to the same conclusion. Somewhere sometime someone said expose for the shadows and develop for the highlights. That might be workable for sheet film users who can develop individual sheets but I don't think it works very well for roll film users. Unfortunately it has become ingrained in the minds of many who write books about b+w photography. Most books on b+w photography are written by people who get their knowledge from other peoples books, fiddle with it, and regurgitate it parrot fashion. Result is everyone believes it's the only way to do it and myths are perpetuated.

And what are incident meters set to do by default and why do they do it?