So many variables! [Archive] - Large Format Photography Forum

mfratt

20-Nov-2010, 23:01

I'm trying to nail down my ideal development process. When I first started, I began looking for the "answers" to my questions about time, agitation, etc, but I quickly found that the only answer was "test, test, test."

So test, test, test I will...

But where to begin?

I'm working right now with Ilford Delta 100 in HC-110 Dil B, using trays.

I need to figure out what I should use as a baseline N development time.

I need to figure out which agitation scheme works best for me.

I need to figure out push / pull times for each stop.

I need to figure out the real-world EI of the film.

And each variable effects each other. My head is spinning with trying to figure out how to test these.

I just finished processing about twelve sheets, two at a time, playing with varying combinations of agitation and time. I developed at 5, 5.5, and 6 minutes (Spec sheet says 6), and for agitation I flipped to the next sheet continuously for the first minute, then cut it to every 5, 10, or 15 seconds. My negatives came out acceptable, but overall pretty flat.

I guess with all this I'm left with two specific questions

a) Where do I begin in my "test, test, testing" when theres so much to test, all of which is inter-related?

b) In terms of agitation, I've seen people suggesting to do things like agitating for 15 seconds every minute. How does this work in tray processing? Do I just flip through the sheets for x seconds then let them sit? Wont the sheets in the middle develop differently in that case? Also, when you flip sheets in the tray, do you bump the tray too to agitate more, or is just the moving of the film enough agitation?

I don't know whats making me more dizzy, trying to quantify all of these variables (which my personality necessitates), or the chemistry I've been breathing in all night.

Thanks in advance for you advice!

Peter Gomena

20-Nov-2010, 23:13

I find slow, constant agitation best for sheet film. I will process up to six sheets of 4x5 film at a time in 8x10" trays, shuffling through the deck about twice per minute. To help with consistency, if I have only four or five sheets to process, I will put one or two "dummy sheets" (failed sheets from previous batches, fixed, washed, dried) into the stack so that the amount of agitation remains the same.

The number of variables is a bit daunting when you're first starting out. Film exposure, developer, development time, temperature, agitation. Consistency is the key.

Peter Gomena

Chuck P.

21-Nov-2010, 08:44

So test, test, test I will...

Trial and error testing will drive you crazy............choose a known system of exposure and development that works i.e. BTZS of ZS. I personnally like the ZS method.

I suggest you learn to test using a 21-step step tablet and a densitometer---keep an eye on ebay for some deals on a transmission densitometer. Once in hand and you understand how to test, it's very simple and quick. You can produce the characteristic curve and determine the EI with one sheet of film. If you wanted to try three different developers with your film, you could produce three characteristic curves and determine the EI for each easily in a day--just trying to emphasize how easy it is once you understand the process. Generating the "plus" and "minus" times is also just as easy.

An excellant text I have found is The Ansel Adams Guide, Basic Techniques of Photography Book 2. Contains a very practical ZS testing procedure using the step tablet.

ic-racer

21-Nov-2010, 13:24

I think you are making it more difficult than it needs to be.

Film speed and development are independent variables.
No need to push unless you want underexposed negatives.
Use multigrade paper and develop everything for N
Set your exposure index with the simple 0.1 test using your own equipment.

22-Nov-2010, 09:44

It sounds like you may still be sorting out film processing. If I'm misreading your post, my apologies. But, if you are somewhat new at it, I'd urge you to batch the solving of all your questions into smaller portions. Your range of questions suggests that you want to get a grip on a very broad bunch of things, all at once. That's laudable, but I think that it may be more productive to start with solving just one problem. Sort it out, and then move to the next...

I'd begin with sorting out an agitation scheme that works for you. If you want the zone system to give you a lot of control, processing consistency is a vital underpinning to it all. There's no magic in any agitation scheme, but the principles behind the various agitation schemes are very widely written about and easy to search on the net. Many threads are searchable here and on APUG ( www.apug.org/forums/forumdisplay.php?f=13 ) on agitation. Some folks have a plan where they agitate 30 seconds the first minute, say 10 seconds each following minute till say the fifth minute and then 5 seconds each minute till... and so on. Some folks just do 30 seconds to start and then 10 per minute thereafter. There's a lot of room for finding what plan fits you. I'm not sure that which one particular plan or other you select matters much within the average range of options, as long as you stick with it absolutely faithfully so that you can get consistent results.

Be consistent with the other basics. Use fresh developer. Use fresh everything. Agitate with the same vigor every time. Keep to the times and temperatures exactly. If you are absolutely consistent in how you develop, it will soon be clear if there is a need to mess with exposure ratings and contrast to perfect your "normal" exposure speed and normal development. After that you will have a really solid jumping off point, and the tools to go as far as you like in the zone system, in as rigorous a manner as suits you.

BW darkroom work and film are really pretty forgiving, and that makes Ic-racer's advise above one very sensible way to go. Keep it simple. If you find you want more control at the negative stage, you can customize the exposure / development tango as much as you want - once your processing is no longer a variable.

mfratt

22-Nov-2010, 11:30

rdenney

22-Nov-2010, 13:26

Very helpful, thank you.

And yes, I am pretty new to film processing. I'm the type of person that, when I find I enjoy something (especially something technical like photography, or my other hat, music), I just try to gobble up as much knowledge as possible about it. Well, theres a Thanksgiving dinner in front of me with this one and I just want to eat it all at once!

But I'll get to work right away at settling myself on an agitation scheme. Makes sense to me.

Remember that Ansel Adams did not devise the Zone System, per se, until many years after he had started as a professional photographer. When he was first learning, he realized that if he set his exposure for the shadows, he could then control the highlights on the basis of how long he developed. He then started experimenting with different development times to see how much he could control the development of the highlights with respect to the shadows. By the time he applied real rigor to that test, he had already cemented his basic technique.

If your film is coming out with even development, then your agitation method is fine, at least for now. Do it that way every time. Establishing that technique is more a matter of what physically works for you moving film sheets in and out of trays, so that you know you can do it that way every time.

If your shadow details have the texture you intended, then you are exposing properly. If you set your exposure on the basis that Zone III measurements would fall on Zone III, and they do, then you have your film speed and basic exposure technique down. Do it that way every time.

Then, it's a matter of determining how long to develop so that the highlights do what you want them to do. If you have texture on subject scenes that fell on Zone VIII, then your basic N development is on target. You'll develop less to attain less contrast and more to attain more contrast. But get that basic development to your satisfaction before trying to alter it. Getting that consistent development will require careful temperature control, but again it's not so much whether it's 68 or 75, but that you can do it that way every time.

Once you have control over basic technique so that you are unconsciously repeatable, then you can start to vary this and that to see what you might achieve in addition to that. By that time, you'll know that you can produce a proper negative for any normal scene, and you'll be able to make adjustments one at a time and see their effects.

Adams made revolutionary photos before he had the details of the Zone System really worked out. It's worth remembering.

Rick "who can only test one thing at a time" Denney

Neal Chaves

22-Nov-2010, 15:19

You may have heard "The first film you develop should be with the lights on." This is good advice since film/developer combinations can be quite different from one another. With sheet film under white light, pull one sheet out of the stack in the developer every minute. Don't loose track of the order into the fixer and wash. So now when dry (hang them in order) mark each with minutes of development and proceed to light box. Note the density difference that one minute changes in development time make. For example, you have five sheets of HP5+ developed in HC110B at 75 deg. for 5, 6, 7, 8, and 9 minutes. Pick the one that would make a good bright snow density or bright white background. You may hear it said that this is the density through which you can barely read a newspaper in bright light.

Now you have a beginning development time and you can expose some film for a speed test. Make some prints of normally lighted subject matter and see how they look. Repeat as needed for other film speeds and contrast control. Remember. Exposure builds density while development builds contrast.

txind76121

23-Nov-2010, 20:23

I never could develop 4x5 film evenly in trays. I wasted a lot of time trying (and if you think you've got it down, try exposing a few sheets carefully to an evenly-lit medium-gray and stick them in your stack. I think you might be horrified at what you find). The View Camera Store still sells BTZS tubes, don't they? To me that's the best method for developing 4x5 sheet film. The BTZS tubes really do give even development.

Shen45

23-Nov-2010, 20:54

All of your questions will be answered with BTZS. Contact the viewcamera store and they can answer some questions for you.

also www.BTZS.org

Steve

Ken Lee

24-Nov-2010, 05:29

This is not rocket science. :)

In fact, after all is said and done, almost everyone ends up with the same film speed. This makes sense, because the same brand of film is unchanging from batch to batch: trained Chemical Engineers see to that. What we're really after, is our developing time.

When shooting, what varies for each person are the light, the light meter, lens and shutter. In the darkroom, what varies for each person are developer, water and method of agitation. I presume that in this day and age, people use a decent thermometer.

So... we test under the same lighting, using one light meter, one lens, and one shutter speed. In the darkroom, we use the same water, the same developer, and agitate the same way each time.

At this point, only two variables left: exposure and developing time.

Just expose your film at several film speeds, and develop for several different times. (By the way, 5, 5.5, and 6 minutes are way too close: if the recommended time is 6 minutes, try 3, 6, and 9. You're more likely to see a difference, and you can interpolate the rest. The same is true with film speed: if the recommended speed is 200, then try 100, 200 and 400).

ki6mf

24-Nov-2010, 06:20

A good step by step Zone system Development Test methology is on line at
http://www.jerryo.com/teaching.htm

This test consists of several parts:
• Finding your Normal developing time
• Using a densitometer if you have one and if not
• The Visual Method
• The practical method
• Finding N+ and N- developing times

Chuck P.

24-Nov-2010, 23:07

Where do I begin in my "test, test, testing" when theres so much to test, all of which is inter-related?

I don't know whats making me more dizzy, trying to quantify all of these variables (which my personality necessitates), or the chemistry I've been breathing in all night.

Before I got a densitometer and started using density step tablets I used the following method---it works--but it also sounds much much more convoluted in written description, like all these type discussions, than it is to perform in actuality, it's the nature of the beast. Like you, my personality and thought processes dictate that I am more precise, hense the densitometer, plus it's so much quicker and uses less materials than any other testing procedure for determining these things. For this test use a textured target, because you will be making decisions based on the lack of texture at -4 stops below the meter (Zone I - speed point) and the prescense of discernible texture at +3 stops above the meter (Zone VIII - calibration point for "N" dev time) reading.
______________________

Film Speed Test:
1)
Use a uniformly textured surface for the test target in uniform lighting without shadows being cast, such as a block wall on the shady side of a building on a sunny day (beware of clouds moving in front of the sun, EVs change quickly). Or, a very uniform overcast day.

2)
Expose 3 sheets the following way after metering the target:
- using the "box speed", say 400, reduce the target exposure 4 stops (i.e. Zone I)
- using one stop less speed, 200, reduce the target exposure 4 stops
- using two stops less speed, 100, reduce the target exposure 4 stops

3)
Before developing, include one unexposed sheet of film for a good determination of film-base+fog (Fb+f) density. Develop all three Zone I sheets and the Fb+f sheet at the same time using the manufacturer's rec developing time and your standard processing habits.
______

If you normally enlarge rather than contact print, then you should carry out the following process by enlargment of the sheets. Choose a standard height, remember it, mark the height of the head on the column, you will also use it for the "N" dev test.

4)
Print the Fb+f sheet using just the amount of exposure time to reach Dmax (complete black) on the print--call this minimum time for maximum black (MTMB)---say it is 15 sec, whatever.

5)
Print the 400 speed sheet for 15 sec
Print the 200 speed sheet for 15 sec
Print the 100 speed sheet for 15 sec, process all normally, include toning if that is part of your standard process.

6)
Observe which print with its corresponding EI that most closely matches a Zone I print tonality as described by AA: "first step above complete black" and "slight tonality but no texture". The EI you will use is the one that can satisfy this requirement. You can interpolate the speed too based on these renderings of various Zone I print values--it's an estimate, you have no densitometer to directly read for a target density of .09 to .11.

Normal Development Test
1)
Again, use a textured target.

2)
Using the EI determined in the film speed test, expose 4 sheets at +3 stops over the meter reading (i.e., Zone VIII).

3)
Develop an unexposed sheet for Fb+f density along with the first Zone VIII exposure using your standard procedure and the recommended time. Develop the next sheet with another unexposed sheet for an additional 1.5 min, and the next pair for another 1.5 min, and so on until all development is complete. It is important to include an unexposed sheet with each for an accurate rendering of Fb+f density. This is because as development time increases, so can the Fb+f density; therefore, the MTMB can be increased and thus it should be accounted for in this process. So, using the MTMB from a negative developed for 6 min may very well not be the same MTMB from a negative developed for 8, 10, or 12 min.

4)
Print each Zone VIII sheet for the MTMB found for its associated Fb+f density sheet. Include toning if this is part of your standard process.

5)
Observe which Zone VIII sheet most closely matches a Zone VIII rendering of texture---highest value in which some texture is discernible, not full texture, that would be Zone VII. Your "N" dev time is that Zone VIII sheet with its development time that can satisfy this requirement.
____________________________

Materials: total 12 sheets, some paper, and some chems
Time: whatever, it is what it is, but well worth it in the end; get a densitometer and a step tablet and save much in materials and time

Jim Burk

25-Nov-2010, 00:55

I do all of my 4x5 development work in 5x7 trays, 6 at a time. I am very satisfied with my results, which I think are very consistent. The key is to get a constant rhythm that you will use every time.

ki6mf

25-Nov-2010, 04:40

Before I got a densitometer and started using density step tablets I used the following method---it works--but it also sounds much much more convoluted in written description, like all these type discussions, than it is to perform in actuality, it's the nature of the beast. Like you, my personality and thought processes dictate that I am more precise, hense the densitometer, plus it's so much quicker and uses less materials than any other testing procedure for determining these things. For this test use a textured target, because you will be making decisions based on the lack of texture at -4 stops below the meter (Zone I - speed point) and the prescense of discernible texture at +3 stops above the meter (Zone VIII - calibration point for "N" dev time) reading.
______________________

Film Speed Test:
1)
Use a uniformly textured surface for the test target in uniform lighting without shadows being cast, such as a block wall on the shady side of a building on a sunny day (beware of clouds moving in front of the sun, EVs change quickly). Or, a very uniform overcast day.

2)
Expose 3 sheets the following way after metering the target:
- using the "box speed", say 400, reduce the target exposure 4 stops (i.e. Zone I)
- using one stop less speed, 200, reduce the target exposure 4 stops
- using two stops less speed, 100, reduce the target exposure 4 stops

3)
Before developing, include one unexposed sheet of film for a good determination of film-base+fog (Fb+f) density. Develop all three Zone I sheets and the Fb+f sheet at the same time using the manufacturer's rec developing time and your standard processing habits.
______

If you normally enlarge rather than contact print, then you should carry out the following process by enlargment of the sheets. Choose a standard height, remember it, mark the height of the head on the column, you will also use it for the "N" dev test.

4)
Print the Fb+f sheet using just the amount of exposure time to reach Dmax (complete black) on the print--call this minimum time for maximum black (MTMB)---say it is 15 sec, whatever.

5)
Print the 400 speed sheet for 15 sec
Print the 200 speed sheet for 15 sec
Print the 100 speed sheet for 15 sec, process all normally, include toning if that is part of your standard process.

6)
Observe which print with its corresponding EI that most closely matches a Zone I print tonality as described by AA: "first step above complete black" and "slight tonality but no texture". The EI you will use is the one that can satisfy this requirement. You can interpolate the speed too based on these renderings of various Zone I print values--it's an estimate, you have no densitometer to directly read for a target density of .09 to .11.

Normal Development Test
1)
Again, use a textured target.

2)
Using the EI determined in the film speed test, expose 4 sheets at +3 stops over the meter reading (i.e., Zone VIII).

3)
Develop an unexposed sheet for Fb+f density along with the first Zone VIII exposure using your standard procedure and the recommended time. Develop the next sheet with another unexposed sheet for an additional 1.5 min, and the next pair for another 1.5 min, and so on until all development is complete. It is important to include an unexposed sheet with each for an accurate rendering of Fb+f density. This is because as development time increases, so can the Fb+f density; therefore, the MTMB can be increased and thus it should be accounted for in this process. So, using the MTMB from a negative developed for 6 min may very well not be the same MTMB from a negative developed for 8, 10, or 12 min.

4)
Print each Zone VIII sheet for the MTMB found for its associated Fb+f density sheet. Include toning if this is part of your standard process.

5)
Observe which Zone VIII sheet most closely matches a Zone VIII rendering of texture---highest value in which some texture is discernible, not full texture, that would be Zone VII. Your "N" dev time is that Zone VIII sheet with its development time that can satisfy this requirement.
____________________________

Materials: total 12 sheets, some paper, and some chems
Time: whatever, it is what it is, but well worth it in the end; get a densitometer and a step tablet and save much in materials and time

This is a very good explanation of how to test. Most of what has been written is lacking in simple easy to follow step by step instructions. Make sure you only test one film and developer at a time. Last week a student of mine decided to switch films in the middle of her film speed test, "I forgot I wasn't supposed too", and could not figure out why the images were not coming out. Complete the testing and if you do any changes re do the entire test procedure for the new film or developer!

Stephen Benskin

4-Dec-2010, 05:13

I'm reading through some of these post and thinking isn't this thread about too many variables? The key is to limit the variables, understand which ones that remain, and always have a clear idea of what you are testing for.

Testing with a camera introduces so many variables you can't be certain what the results represent. There are too many known unknowns and unknown unknowns and unknown knowables.

Question assumptions, and be wary of all anecdotal evidence. There is a common belief that the B&W speed point is four stops down from the meter reading. Is it? That specific negative densities define quality. Do they? That the density of 0.10 above Fb+f is significance. Funny how it just happens to be a nice round number. That there is a normal contrast for a negative? Is there and if so, why?

For a specific example, there's the testing methods in John Schaffer's book The Ansel Adams Guide: Basic Techniques of Photography. He describes taping a step tablet onto a sheet of film inside the camera and exposing it five stops above the meter reading. Why five stops? Why not five and a half or six stops? Is it because five stops above the meter reading correlates with the various exposure and speed equations? He doesn't go into detail. Or could it be that five stops is simply close enough to produce the type of results expected and without an outside method to test it against, how would anyone know if the film speeds the technique produces are 1/3, 1/2 or even 1 stop off? Is the light at the film plane of a view camera evenly distributed or is there light fall off as you move further off the lens axis? Isn't the two ends of the step tablet, which are the most critical sections of the step tablet, furthest away from the lens axis? What would the affect of any off axis light fall off have on the test results? Schaffer never addresses it.

Some of the answers might not agree with what is commonly assumed.

Work through and define everything one step at a time. Question everything and then question the questions. Eventually you will have something that will work for you.

Chuck P.

4-Dec-2010, 14:45

Schaffer never addresses it.

He doesn't need to and I'm not suggesting that you are wrong about anything.

One either accepts that particular testing procedure (which is fundamental ZS testing utilizing a step tablet rather than lots of film and lots of chems to complete the same task) and moves on to photographing using their results. Or, they can go on a quest to prove one procedure is more right than another or that somebody got wrong many years ago.

No, all that is irrelevant. What matters in the end is results, regardless of some flaw, real or perceived, in the testing procedure in question. What matters is results (in the negative and on the paper's surface) and what the photographer can do with them and you simply can't argue with that, no matter what mathematical premise you may put forth or flawed mechanism that you can prove. I cannot rest my eyes on an AA print or a Sexton print or even some of Ross' prints and (I'm sure there are many others that test the ZS way and have great results) find where any previous argument you have made against the ZS method of testing should be given any serious merit.

No malice or sarcasm here, just an opinion.

neil poulsen

4-Dec-2010, 16:33

To begin with as much consistency as possible, you might start with Ansel Adams as others have suggested. I'm not familiar with the Ansel Adams Guide series, but I am familiar with his three books, Camera & Lens, The Negative, and The Print. And, they are masterful.

Answer as many of your questions as you can from his books, like agitation, development, and other basic technique questions. That gives you a good baseline that you can improve later on, if you decide to do that. But for now, this cuts down on many of the questions that you have. There are also many good suggestions above. The point is, pick a basic technique and stick with it for a while.

Then consider the following in order:

1. Test for film speed. (Do you have a densitometer?)

2. Pick a paper that has normal contrast and determine a distance, exposure, f-stop, and development time that just gives you a maximum black (minimum exposure time to achieve maximum black) on that paper when printed through Zone One.

3. Determine your Normal Development.

4. Determine N+1, N-1, N+2, and N-2 development times.

5. Take pictures!

One could go into detail on each of these, but much has been already written. You'll eventually arrive at your own technique for each. As you go through them, you can of course ask questions.

In this process, maintain as much consistency as possible, especially in development times, concentrations, and temperatures. This is probably overkill, but for example, my development temperature stays within about 0.3 degrees Fahrenheit. Etc.

Once you complete this process, if you like the film-developer combination that you're using, you won't really need to do much further testing for quite a while. (So, testing can come to an end.) Just take more pictures. Unless of course, you want to improve on your system.

Stephen Benskin

4-Dec-2010, 21:51

No, all that is irrelevant. What matters in the end is results, regardless of some flaw, real or perceived, in the testing procedure in question. What matters is results (in the negative and on the paper's surface) and what the photographer can do with them and you simply can't argue with that, no matter what mathematical premise you may put forth or flawed mechanism that you can prove. I cannot rest my eyes on an AA print or a Sexton print or even some of Ross' prints and (I'm sure there are many others that test the ZS way and have great results) find where any previous argument you have made against the ZS method of testing should be given any serious merit.

There are examples of excellent prints made from every method under the sun. This is not a legitimate argument. Brett and Edward Weston never used a light meter and they made amazing prints. Adam's Moonrise is a beautiful image but it is well known that it wasn't exposed correctly. So let's not confuse printing prowess with exposure theory.

All I was suggesting is to do some critical thinking and not blindly accept everything unquestioningly. I used Schaffer as an example because he was brought up in the discussion. There was also the recommendation of the approach as describe at http://www.jerryo.com/teaching.htm., and a recommendation for BTZS.org. Any of these could have been used as examples just as easily. Each of these methods will all produce good negatives in most situations. Almost any method will, primarily do the preponderance of scenes falling within a rather narrow band of luminance ranges (bell curve).

To believe every aspect of the above system's methodologies are entirely without imperfections would be naive. Just as it would be simplistic and naive to suggest negating the validity of an entire methodology because it might contain inaccuracies. Understanding the strengths and weakness of any system or methodology isn't irrelevant. It's insight.

The Zone System uses basic sensitometry. Schaffer is taking it a step farther utilizing a more systematic and scientific approach. It's still an abridged version of tone reproduction theory. Your argument suggesting that I am somehow against using a more scientific approach is an obvious straw man argument when what I am actually doing is pointing out potential problems in the methodology.

It's not unreasonable to wonder if the light fall off toward the outside of the image circle affects the resulting densities. And just because Schaffer didn't address it doesn't mean it's not important. It's a potential variable. Define it, explain it, and rule it out or fix it, and then there's one less variable to worry about or to influence the testing.

It's not unreasonable to ask if exposing the step tablet within the camera five stops over the meter reading is the correct exposure. On the contrary, it's absurd not to expect an explanation?

It's also not unreasonable to wonder how the negative relates to the print. Schaffer doesn't have any paper curves in the book. The negative is an intermediate step in the photographic process. In order for any of the negative parameters to have any relevance, the negative needs to be evaluated in relation to the print and the original scene. Then those variables are define and potentially controlled.

All this can lead to improving any given testing method. In my book that is far from from being irrelevant.

I've attach an example from my four quadrant reproduction program which shows the negative in context and illustrates how all the elements interact.

Bill Burk

4-Dec-2010, 23:20

Rick "who I swear knows everything" Denney mentioned that Ansel Adams worked up the ZS over years. My mind is still swirling over the concept that I never thought of but I know has to be right.

I know you have no money for anything extra, so what you need first is a Stouffer step wedge. I still have the one I bought at the student store when I went to Cal Poly with Weird Al. It's worth the ten bucks.

If someone wants to give you a densitometer - take it. People _are_ giving them away. It doesn't have to be accurate to be useful - just reasonably consistent.

Stephen Benskin taught me to separate the film behavior from the camera. As I understand, his opinion is that camera tests include "all the variables" with "none of the control".

But if you _have_ to use a camera shutter to get a consistent time exposure in a home-brewed sensitometer that you make using that Stouffer scale under an enlarger - that's not a camera test. The exact light type and time is _not_ important for test strips, Consistency is. Once you make the setup, "shoot" several test strips and pack them away in a special box. Run one of the strips every time you develop and you can "compare" them with each other to see if your development is consistent.

---
OK that's the film.
---

Camera. I'll introduce what I think was a radical one-off idea that nobody really uses but is great to illustrate eliminating variables:

I just read the old Zone VI newsletter that explains the four possible mistakes you can make when taking a picture:

1. F/Stop too small
2. F/Stop too large
3. Shutter too fast
4. Shutter too slow

He said you can solve three of those problems by:
1. Use F/22
2. Find the fastest shutter speed that will _ever_ work with F/22 and use it.

Now you eliminated three of the four possible mistakes. If the light is less than what you would need the highest shutter speed for, pick a lower shutter speed. Still the only mistake you can make is to use a shutter speed that is too slow.

Stephen Benskin

5-Dec-2010, 00:08

Attached are the guideline data points for the above example. FYI, both the four quad and the guideline data points are generated by a program I am currently writing.

Chuck P.

5-Dec-2010, 08:14

All I was suggesting is to do some critical thinking and not blindly accept everything unquestioningly.

That's just it, you assume everyone that tests this way is just blindly moving forward with their results and that they may be understanding the wrong idea behind what it is that they are doing and the results that they are producing.

I will always contend that your arguments on this subject (regardless of validity--I'm sure they are valid, never said they were not) serve your own intellectual ego more than for any other reason.

Like I said, what matters are results, there are many that have experienced excellant results with this method and have the prints to prove it-----but I suspect you will always contend that there results were reached the wrong way.

Or, perhaps if one could be so lucky to be standing in a gallery viewing a fine Adams or Sexton print next to you, they would be so fortunate to know that the negative the print came from is flawed because the testing method that guided the making of the negative did not consider "off axis light falloff".

If there is someone reading this that wants to test using what is in the AA Guide Basic Techniques of Photography Book 2 by Schaeffer, then do it! Your photography will improve by leaps and bounds. Don't allow the anal and intellectual musings of someone else stiffle your curiosity and desire to improve in the simplest manner that may be available to you. Listen first to your "results", both in the negative and how it transfers to the print. If you then feel that splitting the frog hair is warranted, then by all means, man, split it.

I am done, you can have the last word. Have a good day.

Stephen Benskin

5-Dec-2010, 11:10

That's just it, you assume everyone that tests this way is just blindly moving forward with their results and that they may be understanding the wrong idea behind what it is that they are doing and the results that they are producing.

Yes I do. And so do all those others who come up with their own methodology. BTZS falls into that category. Schaffer's book does too. It's obvious even from a cursory point of view as Adams never taught the use of step tablets and they do.

It's the same in the photographic scientific community. How many different methods of determining film speed have there been over the years? Should everyone have stopped experimenting for a better approach after the inertia method? Should they not have challenged the assumptions that went along with the various methods that were in use and eventually discarded?

I, for one, want to know to the best of my ability that after putting all the time and trouble into determine the speed and contrast of my film that the results are accurate. That's one of the reasons why I use a calibrated sensitometer with a calibrated step tablet. Yet I know that isn't enough to insure the results. I know I have to incorporate a "hold time" between exposing and processing the film. A topic I have yet to see discussed in any popular "system". I know that determining the film speed using a fixed density method isn't as accurate as using the fractional gradient method, to name a few.

I can name three or four contemporary ways to determine the contrast of film. They can't all be 100% accurate in all aspects, yet they all have to produce quality results or they would no longer to be used. Why care which one works best in the greatest number of situations? To some of us, it is who we are and it is important. The Sun going around the Earth seems to work as an explanation of the observed phenomenon. Why challenge it (sadly a recent poll shows 18% of the population haven't)?

Do any of these universally heard "facts" sound familiar?
- Meters sees 18% reflectance.
- Speed Point (and I'm not talking Zone I) is four stops down from the metered reading.
- 0.10 is the minimal usable density.

They are all incorrect to some degree. So yes, I do think it's important to have a good portion of intellectual skepticism and not to blindly accept as faith everything one reads.

This is a technical forum and should be open to technical discussions even if they challenge fundamentalist beliefs. If someone disagrees with a point, they have the option to challenge it using facts. Others then can support it also using facts. Everyone benefits from such exchanges. The entire structure of the four quadrant reproduction curve I uploaded is based on theory. Explore it, challenge it, prove it wrong. Whatever the outcome, the end result will be a better understanding of the photographic process.

No one benefits from defensive non-sequitur ranks devoid of facts. Those who want to ignore facts and suppress information can saddle up their Triceratops and ride over to a young Earth site where they can deign science all they want.

rdenney

5-Dec-2010, 15:04

I, for one, want to know to the best of my ability that after putting all the time and trouble into determine the speed and contrast of my film that the results are accurate.

Stephen, we should remember that the OP was suffering from technical overload, and needed a way to simplify his testing, not complicate it. We should also remember that people got pleasing, consistent, and even predictable results without ever using a sensitometer or a rigorous testing regime. Those things are fun to do and to discuss, and for someone asking about those technical issues, let the details fly. But we have to be careful not to present someone already paralyzed with too much to think about with even more detail to ponder.

From a systems engineering point of view, your process seems to be focused on verification--whether the system fulfills the requirements. And the requirements are defined in detail in your model, including density targets and so on. The question is whether those requirements do really trace back to what any given user might need.

But the OP was asking for validation, to determine where to start with a process needed to meet his needs and support his photographic objectives.

It is useful to keep these processes separate. Verification should serve validation, not the other way around.

Rick "often in the role of monitoring the test plan development and the testing of highly complex systems" Denney

Stephen Benskin

5-Dec-2010, 15:27

My first post was for the benefit of the OP. The other two were directed elsewhere.

I believe if you are able to define the variables one by one, you can take control and not be overwhelmed. It's taking on everything at once before understanding the component parts that appears to be the cause of the OPs stress.

Jay DeFehr

5-Dec-2010, 16:46

Steven,

I agree with you 100%, and thank you sincerely for your original thinking and detailed explanations.

To the OP: Why bother testing at all? The manufacturers of your films, papers, and developers have done more than enough testing to provide you with the information required to produce good results. Shoot at box speed, develop according to instructions, and print on VC paper to make any necessary corrections. If you want to know about sensitometry, you'd do well to pay attention to Mr. Benskin's posts.

The idea that "The proof is in the pudding", and good prints equate to good sensitometry is, of course, ridiculous, and illustrates just the kind of irrational thinking that confounds so many dark room workers. I think most photographers would agree testing is not a prerequisite to producing excellent work, and some would even agree that testing can be a needless distraction. I believe testing and making photos are related, but separate pursuits, and the more testing I do, the more liberal I become in my approach to making my photos. I rarely use a light meter, and estimate my development based on my subjective evaluation of the lighting conditions and my goals for the print. While it's undeniable my estimations, evaluations and guesses are informed by my intensive testing, there is no direct application of my testing to my photography. So, test if you like, or don't; I don't think it matters much, and I don't think your photos will be remarkably different, either way. The most important thing, is to enjoy your process, whatever it is. Good luck, and have fun!

Stephen Benskin

5-Dec-2010, 17:40

The idea that "The proof is in the pudding", and good prints equate to good sensitometry is, of course, ridiculous, and illustrates just the kind of irrational thinking that confounds so many dark room workers. I think most photographers would agree testing is not a prerequisite to producing excellent work, and some would even agree that testing can be a needless distraction. I believe testing and making photos are related, but separate pursuits, and the more testing I do, the more liberal I become in my approach to making my photos.

I wish I had said that.

Bill Burk

5-Dec-2010, 21:41

Ah, but there _is_ a purpose to this testing. By whatever form it takes, it gives the photographer a deeper understanding. I would assert it is the learning, it is the journey that is important, not the results.

Musicians practice their scales. This helps them learn their instruments quickly. You can play by ear with no formal practice and still make beautiful music.

Photographers can acquire understanding very quickly by performing _any_ systematic testing. It's similar to playing scales.

But even without doing any system testing, like playing by ear, beautiful images can be made.

BillA

26-Feb-2011, 19:50

Tim k

27-Feb-2011, 10:59

Remember that Ansel Adams did not devise the Zone System, per se, until many years after he had started as a professional photographer. When he was first learning, he realized that if he set his exposure for the shadows, he could then control the highlights on the basis of how long he developed. He then started experimenting with different development times to see how much he could control the development of the highlights with respect to the shadows. By the time he applied real rigor to that test, he had already cemented his basic technique.

If your film is coming out with even development, then your agitation method is fine, at least for now. Do it that way every time. Establishing that technique is more a matter of what physically works for you moving film sheets in and out of trays, so that you know you can do it that way every time.

If your shadow details have the texture you intended, then you are exposing properly. If you set your exposure on the basis that Zone III measurements would fall on Zone III, and they do, then you have your film speed and basic exposure technique down. Do it that way every time.

Then, it's a matter of determining how long to develop so that the highlights do what you want them to do. If you have texture on subject scenes that fell on Zone VIII, then your basic N development is on target. You'll develop less to attain less contrast and more to attain more contrast. But get that basic development to your satisfaction before trying to alter it. Getting that consistent development will require careful temperature control, but again it's not so much whether it's 68 or 75, but that you can do it that way every time.

Once you have control over basic technique so that you are unconsciously repeatable, then you can start to vary this and that to see what you might achieve in addition to that. By that time, you'll know that you can produce a proper negative for any normal scene, and you'll be able to make adjustments one at a time and see their effects.

Adams made revolutionary photos before he had the details of the Zone System really worked out. It's worth remembering.

Rick "who can only test one thing at a time" Denney

I think this is very sound advice.