Zone vs. BTZS(SBR) Why?

Since I am switching fro a Jobo to BTZS tubes I sat down and decided to reread my copy of Beyond The Zone System (BTZS) by Phil Davis. In the past, when I have read his book I have dismissed parts of it as overcomplicating the zone system. However, my primary dislike was Davis' preference for incident metering.

First, I am a big fan of my Pentax digital spotmeter. I just can't seem to understand how an incident meter could work for every situation. For example, lets say that I was taking a picture at Yellostone's famous Artist Point overlook. Now the overlook is heavily shaded by trees. However, the waterfall in the distance is illuminated by the morning sun. Not being able to move from the overlook towards the point, how could you meter with the incident system to determine the contrast (SBR) of your scene?

Second, one thing I do like about Davis' BTZS method is that he includes the printing paper's testing into the system. THis is not to say that Ansel didn't, as his book The Print includes a section on testing paper. However, Davis argues that one should start with testing the paper and work backwards to produce a negative to fit. Ansel seems a bit more general in producing a negative that targets grade 2 and is adaptable to a variety of papers. Thus, perhaps the question is how specific do we need to be for variable contrast papers? I can see that one might argue for tighter controls with AZO or alt processes; however, do we need to be this tight with variable contrast silver paper?

The zone system is so elegant and simple. Why would I want to complicate it by carrying a PDA with exposure software? With the zone system I can meter the shadows and the highlights, calculate the exposure and development, adjust for filters and/or bellows, and take the picture. I can do all this in my head, what could be simpler?

So, how many people here actually use Davis' system exactly as he designed it?

I started out with a BTZS pocket computer in the field but eventually got rid of it as I find myself not needing it anymore. I keep a notebook with all possible combinations of SBRs, f stop and speed. In addition, through trial and error, I have modified my exposure measurements to take into account my use of a spotmeter. The BTZS system is a great system and one should adhere to it when trying it out for the first time. Use if for a while and make adjustments accordingly. Keep notes, especially as you are going to use a spotmeter. The best thing about it: you really will focus on achieving the correct negative for the paper you will (most often) use.

I have been thinking along these same lines lately.

I have used the "Zone System" up to this point with good results. But now that I am wanting to do some landscape photography I find that my exposures are off (probably because I'm not metering the scene correctly).

I'm sure that with some adjustments I could get them zeroed in, but I decided to order Davis' book and the ExpoDev software for the Palm.

It looks like a good system and I'm going to give it a try.

Jim

Francesco said:

Keep notes, especially as you are going to use a spotmeter.

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I have to admit that I am NOT good at keeping notes. (Bad..Bad.. Jim )

That is one of the features that I'm looking forward to in the ExpoDev software.

Jim

I'm not so sure about BTZS yet. It seems like so much trouble for so few (any?) gains.

Part of BTZS is not much different from the zone system in that we need to know two important pieces of information. First, how much exposure is necessary? Second, how much development?

With the zone system this is quite simple. Meter the shadows and determine the proper zone. This will give you an exposure. Then, meter the highlights and determine the proper development. This is based on the range of luminosity in the scene. Furthermore, selecting proper development is based on prior testing of your darkroom materials. That is, we select a develoment (N, N-1, N+1) based on our previos testing of our oft used printing papers. With VC paper we can aim in the area of our most oft used papers and be able to print without any problems.

With the BTZS system we again need the shadow and highlight meter readings. These are used to determine the proper contrast range (SBR). This is all done for us with the handy computer when we plug in the two meter readings. Then, the computer also helps us compensate for bellows and filters. Of course we need to do this with the zone system too. Finally, the computer suggests an exposure. Of course, everything that the computer does is based on our prior darkroom tests.

I still don't understand the benifits of using the BTZS system over the zone system. Both will give me properly exposed negatives. THe zone system just lets me do it in my head vs. BTZS requiring formulae and computers.

Both will give me properly exposed negatives. THe zone system just lets me do it in my head vs. BTZS requiring formulae and computers.

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I completely agree. But since I am going to start shooting 8x10 for contact printing on AZO and need to test all over again I decided to give it a try

Jim

DrPhil said:

I still don't understand the benifits of using the BTZS system over the zone system. Both will give me properly exposed negatives. THe zone system just lets me do it in my head vs. BTZS requiring formulae and computers.

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The BTZS is a closed loop system, you first test the paper to see the range of "tones" it can accommodate and then tailor the negative to that specific range. While the zone system is an useful tool and as you say it is very simple, it has the flaw of not taking into account the paper, so the target densities for a negative are those set by others, many a times the DR recommended by zone system users is too high and results in negatives less than optimum for printing.

I know, I used the ZS for many years, while the BTZS book sat on my shelve.
I can kick my self in the butt for not giving the BTZS a chance before, since I started using it my percentage of keepers has increased tremendously.

A reformed ZS user....

I have always determined the density range of my paper (for each grade) by exposing a stouffer step wedge in my enlarger. Some papers, such as MGIV, have a much broader range than others, i.e. ilford MG warm tone. I used the MGIV at grade 2 to determine my optimum developing time. That is, I tested my paper first. Then, using the results from grade 2, I can determine the exposure range for that paper. Thus, I know what it will take to produce full white and full black. This exposure range is then determined by the density range of the negative. Thus, I aim to develop my negatives to produce this density range in my nagatives. This is described by Ansel on page 143 in The Print.

Ignoring for the moment creative modifications, done by changing to a different grade, I would want to create a negative with a density range that will match my paper. Thus, I test my developing times to determine the necessary times to generate this density range.

These times are then used when I determine the proper exposure and development for my negative.

As far as I can tell both systems are closed loops. That is, both use the results from a previous final product (testing of papers) to determine exposure and development in the field. Thus, both will yield a negative that is matched for a particular paper.

However, I will point out that Ansel does not seem to emphasize this in his writing. Instead, Ansel seems to emphasize that an artist can use the information from these test to adjust the exposure, development and/or printing to fit their vision. Davis seems to emphasize control throughout the process.

DrPhil said:

I have always determined the density range of my paper (for each grade) by exposing a stouffer step wedge in my enlarger. Some papers, such as MGIV, have a much broader range than others, i.e. ilford MG warm tone. I used the MGIV at grade 2 to determine my optimum developing time. That is, I tested my paper first. Then, using the results from grade 2, I can determine the exposure range for that paper. Thus, I know what it will take to produce full white and full black. This exposure range is then determined by the density range of the negative. Thus, I aim to develop my negatives to produce this density range in my nagatives. This is described by Ansel on page 143 in The Print.

Ignoring for the moment creative modifications, done by changing to a different grade, I would want to create a negative with a density range that will match my paper. Thus, I test my developing times to determine the necessary times to generate this density range.

These times are then used when I determine the proper exposure and development for my negative.

As far as I can tell both systems are closed loops. That is, both use the results from a previous final product (testing of papers) to determine exposure and development in the field. Thus, both will yield a negative that is matched for a particular paper.

However, I will point out that Ansel does not seem to emphasize this in his writing. Instead, Ansel seems to emphasize that an artist can use the information from these test to adjust the exposure, development and/or printing to fit their vision. Davis seems to emphasize control throughout the process.

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You made an intituitive leap in the ZS and recognized the need to adjust neg range to paper. Most books in the ZS, if not all, give you a set range for which to develop your zones and leave it at that. Then of course comes the "the print" book where they have to teach you all kinds of darkroom tricks, I have them all....

Seems you have a system that works for you, why worry what system is best? Having used the ZS for many years, I find the BTZS gives me far better results, but then in pt/pd it is hard to burn/dodge and use all the tricks one normally uses in the darkroom. IMO for pt/pd all of the work is done in the negative at the time you take the picture, of you mess that up, printing controls are very limited, so I want the most precise method of producing a negative.

If you are satisfied with your negatives and prints, who cares what you use?

Jorge,

I can understand the rationale behind using the BTZS system for platinum. I agree that it gives you the control that you would want for alt. processes. Well, untill someone comes up wih VC platinum Anyways, I think JDEF best stated what I was trying to say. I am quite happy with my method of working. Honestly, I was just trying to figure out everyone's excitement lately with BTZS. In my mind it is more than is needed with vc papers.

Thanks for putting up with me!

DrPhil said:

Jorge,

I can understand the rationale behind using the BTZS system for platinum. I agree that it gives you the control that you would want for alt. processes. Well, untill someone comes up wih VC platinum Anyways, I think JDEF best stated what I was trying to say. I am quite happy with my method of working. Honestly, I was just trying to figure out everyone's excitement lately with BTZS. In my mind it is more than is needed with vc papers.

Thanks for putting up with me!

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Actually Phil, I consider pt/pd the first VC process ever. You can vary the contrast, and now with with Sodium platinate even to a greater degree than before. IMO is best to shoot for a perfect negative and then use the alternatives to fine tune. The problem with the BTZS is that it is a very simple method that requires to read a book that can be boring to read and follow. In my case, since I have stated using the BTZS I have done far less testing than I did with the ZS. Also the testing is far easier than the one for the ZS.

DrPhil said:

The zone system is so elegant and simple. Why would I want to complicate it by carrying a PDA with exposure software? With the zone system I can meter the shadows and the highlights, calculate the exposure and development, adjust for filters and/or bellows, and take the picture. I can do all this in my head, what could be simpler?

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There is absolutely nothing elegant and simple about the Zone system in my opinion. The trial-and-error testing procedures used to determine effective film speed and development time are extremely laborious, and they must be repeated for subject lighting conditions that require expansion and contraction development. And second, the results, which are evaluated by visual comparison, are somewhat arbitrary because all visual comparisons are inherently subjective in nature.

BTZS testing, which relies on sensitometry, is capable of providing much more useful data about our films in far less time than the trial-and-error testing that has been traditionally used with the Zone System. A couple of hours testing film with the BTZS system can provide a photographer with virtually everything he or she needs to know about exposing and developing film for the specific requirements of a given process, regardless of the lighting conditions of the subject. Acquiring an equivalent amount of information by trial-and-error procedures as used for Zone System testing would by contrast would take many days.

Another consideration is that the data you collect brom BTZS testing can be used for both the SBR Incident system of metering, or with a spot meter with the Zone system. Zone system data, ion the other hand, is useful only for reflective metering. This is important for me because I generally prefer incident metering there are times when Zone system metering will give better results.

BTW, the fact that one uses BTZS does not mean that you always teake very extensive field notes about lighting conditions and expose and develop every sinlge negative according to a formula. To the contrary, once you have become familar with the system it is every bit as intuitive as the Zone system. The ExpoDev program, for example, while extremely accurate, is certainly not necessary for the majority of lighting conditions. I myself only use it for very complicated lighting situations that involve reciprocity and/or filter adjustments. In these cases I trust it much more than my own calcluations. For the majority of situations I simply calculate the SBR of the scene, meter in the shadows and make the negative. Takes less time than Zone metering and is much less subject to gross operator error.


Sandy King

DrPhil said:

Jorge,

Honestly, I was just trying to figure out everyone's excitement lately with BTZS. In my mind it is more than is needed with vc papers.

Thanks for putting up with me!

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The excitment is in the simplicity of BTZS testing and in its precision. Regardless of what process you are using it is always good practice to make the best possible negative. And once you get beyond the initial learning curve BTZS testing is both easier, takes less time, and provides far more useful data than Zone system testing. So why spend more time to get less precise results?

Sandy Kiing

And one more thing. If you buy the WinPlotter program it comes on a disk with testing by Phil Davis of hundreds of film/developer combinations that you can apply immediately. You may have to calibrate the data to your working conditions but in most cases the results that you and I would get from testing a film and develper are very similar so if you develop your film for the condtions described your results should be very similar.

Unfortunately the film testing data provided by Davis is primarily for regular silver gelatin printing and is of limited use for alternative printing. And very few if any of his tests were made with pyro staining developers. But for that there are quite a number of photograhers using pyro staining developers who can provide useful data.

Sandy

Simplicity? How about never having to worry about where to place what in which Zone and then figuring out f stop and speed that averages those placements. Meter low EV, meter high EV (or look at the scene, and through experience say 8 or 7 or 9 SBRs). Set the aperture and speed accordingly, note the SBR for devt time later, then shoot. One shot! Allows much more time for composition, focusing, and seeing - for me anyway.

After you have used any system for some time, whatever its logic may be, you will be able to use it without any metering as long as you stay in your neighborhood. West Virginia is mine now. It was once upon a time the rehearsal stage of a symphony orchestra. If I moved west of the Mississippi, my instincts would no doubt have to be revised. I would probably resort to BTZS to accomplish the revision.

As with some others, I don't see the point of arguing the supremacy of one system over the other. How was my grandfather, in his limited number of years which ended in 1905, able to get over 100 5X7 glass negatives that I can print now? I do see the need for presenting as many systems as are known so that one may make a choice. I gave private oboe lessons for a number of years, and found that different students responded better to one approach or another. The important thing about the oboe is what goes on inside the mouth, which I can't demonstrate very well while playing, so I must resort to different analogies for different students. Granted, some will still sound like a wounded duck, but that is because they don't have a tonal concept. Of course, we photographers each have a tonal concept, don't we?

gainer said:

As with some others, I don't see the point of arguing the supremacy of one system over the other.

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I agree with you, if the issue is which system you use to meter in the field. However, if the issue is film testing there is no doubt but that BTZS is superior in that it can give you much more useful data in far less time than Zone system type testing. Now, if you never use but one film or one developer both systems should serve you equally well. But if you happen to be someone who likes to experiment with different film/ developer combinations, as I do and suspect that you do as well, there is absolutely no doubt but that BTZS testing is superior in that it gives you far more useful data with much less testing.

Sandy King

gainer said:

After you have used any system for some time, whatever its logic may be, you will be able to use it without any metering as long as you stay in your neighborhood. West Virginia is mine now. It was once upon a time the rehearsal stage of a symphony orchestra. If I moved west of the Mississippi, my instincts would no doubt have to be revised. I would probably resort to BTZS to accomplish the revision.

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Agreed Patrick, I have found that most of my exposure/development times fall within a certain narrow range that if done repeatedly one can learn to "see" the light and the resulting exposure/development combo. Nevertheless, I still require my security blanket...

Yes, I agree there. The Zone system leaves a certain leeway in visualization in that one man's Zone 2 mau be another man's Zone 3. A numerical scene brightness range visualized in terms of a numerical paper density range, and a contrast index obtained by a least-squares fit of a straight line to a definite portion of an H&D curve are not easily personalized. It is a little more difficult to impersonalize the nuances due to other than random deviations from the straight line, but we use terms like long toe, etc.

It is certainly easier for me to convey the results of my tests to you and vice versa using BTZS numbers, especially if I can provide the H&D curves.

I forgot to add that from what I have read of Hurter and Driffield's work, the BZTS is more like their understanding of things. They dealt with numbers and equations relating speed, density and contrast to time, temperature and developing agent. Using their concepts, I can take the results of three different tests to determine contrast index, two at one temperature and the third at a different temperature, and derive an equation from which I can prepare a chart of CI vs time and temperature that is accurate enough for practical work. But I am by nature an engineer. If I were teaching the photographic process, I would feel obliged to adjust my teaching methods to feedback from my students.

sanking said:

The excitment is in the simplicity of BTZS testing and in its precision. Regardless of what process you are using it is always good practice to make the best possible negative. And once you get beyond the initial learning curve BTZS testing is both easier, takes less time, and provides far more useful data than Zone system testing. So why spend more time to get less precise results?

Sandy Kiing

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So I sat down yesterday and reread Davis' book. Did many of his end of chapter questions too. In the end, my conclusion is that Davis has significantly refined Adam's zone system. The underlying idea is still the same; however, Davis has made improvements in several areas. First, his testing procedure is much more refined than Adam's methods. Less film and better data is always a good thing. Second, Davis logically starts with paper as the initial point for testing. Third, using the data from Davis' BTZS test you can mix and match different papers and films more easily than with the traditional zone system. Fourth, Davis presents us with a refined method of determining development. Instead of fixed N numbers we have SBR numbers. Using a Dev. time vs SBR graph we can get the equivalent of N-0.5 or N+1.2 etc. Not a new idea from Adam's method, just a more elegant solution. Finally, the fifth improvement is the one area where I still have trouble. Davis is a major proponent of incident metering. I borrowed a friend's incident meter and still don't have the hang of it.

Sandy's quote above made the most sense to me. My initial idea was simply to make an acceptable negative that certainly could be printed; however, Sandy's point struck a cord with me and I am going to give BTZS a whirl..Indeed, I called and talked to Fred Newman today and ordered a bunch of BTZS stuff. I might actually take one of his workshops too as I still don't get the whole incident metering method. Conceptually it make sense; however, in practice I feel a whole lot more comfortable with the spotmeter. Perhaps because I have used it for so long.

Anyways, what am I currently going to use now? I am going to test my film Ilford FP4+ for pyrocat HD. I will use the plotter program to create my variuos curves for Ilford MGIV paper. I ordered a powerdial with the plotter program to use as well. My current plan is to continue to use N numbers instead of SBR. My primary reason for this is that I haven't come up with a good method for keeping all of the negative separate for the proper developing. Since I am not using readyloads, how could I possibly keep 400 sheets of FP4+ separate from each other? Especially if each sheet has its own individual developing time. Three boxes for N, N-1, and N+1 seems easier in this regard. Does anyone have a suggestion here?

I use a mixture of BTZS and spotmeter (I can't stand incident meters) - trial and error is how I arrived at a solution. Do not fret. Stick with your spot meter and get the hang of it with BTZS.

Francesco,

Do you use N numbers to separate your sheet film for development? Or do you use individual SBR numbers to specify the precise developing time for each sheet?

I use SBRs in half step increments to dictate development time.

sanking said:

Acquiring an equivalent amount of information by trial-and-error procedures as used for Zone System testing would by contrast would take many days.

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In addition it takes quite a few boxes of film and paper, a fact to which my credit card statement will attest most eloquently.