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

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rbultman

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Just to give another twist, here is the system that I use with my students. They all find it quite boring but, in one day, they are able to achieve results better than many people who have spent years 'experimenting'. By the way, if you choose to use a two-bath developer (such as Barry Thornton's) you can ignore the second development time tests.

The real key to testing a film/developer combination is to use a consistent and repeatable system. For your information, here is the testing system that I have taught for many years:

Now the key to achieving consistently good negatives is the correct placement of your shadows when exposing the film and ascertaining the correct development time for achieving good separation without losing the highlights. A simple and relatively quick way to way to pin all this down for the future is to do the following (WARNING: reading these instructions is more time consuming and a lot more laborious than actually doing it!!):

1. Find a scene with with a good range of tones
2. Using the box speed, meter the darkest area in which you wish to retain shadow detail
3. Move the camera so that you are only photographing this shadow area
4. From the meter's reading close down the aperture by 2 stops or increase the shutter speed by two stops and then expose 6 frames at: the given exposure then +1 stop, +2 stops, -1 stop, -2 stops and -3 stops less than the meter has indicated

5. Process the film

6. Using the frame that was exposed at -3 stops less than the meter indicated (which should be practically clear but will have received lens flair and fogging - i.e a real world maximum black rather than an exposed piece of film that has processing fog) and do a test strip to find out what is the minimum exposure to achieve maximum black - Print must be fully dry before assessing this
7. Do another test strip with the first exposure being what you have selected for achieving maximum black minus your dry-down compensation then plus 1 second, 2 seconds, etc
8. The time that achieves full black inclusive of compensation for dry-down is you minimum exposure to achieve maximum black for all future printing sessions - print must be fully dry before assessing
9 You now know the minimum time to achieve full black inclusive of exposure reduction to accommodate dry-down
10. Using this minimum exposure to achieve maximum black exposure time, expose all of the other test frames.
11. The test print that has good shadow detail indicates which exposure will render good shadow detail and achieve maximum black and provides you with your personal EI for the tested film/developer combination

12 If the negative exposed at the meter reading gives good shadows, your EI is (when metering shadows where you wish to retain good detail) the box speed (i.e. for 400 film you need to set your meter at 400)
13. If the negative exposed at +1 stop more than the meter reading gives good shadows, your EI is (when metering shadows where you wish to retain good detail) 1/2 the box speed (i.e. for 400 film you need to set your meter at 200)
14. If the negative exposed at +2 stops more than the meter reading gives good shadows, you EI is (when metering shadows where you wish to retain good detail) 1/4 box speed (i.e. for 400 film you need to set your meter at 100)
15. If the negative exposed at -1 stop less than the meter reading gives good shadows, you EI is (when metering shadows where you wish to retain good detail) double the box speed (i.e. for 400 film you need to set your meter at 800)
16. If the negative exposed at -2 stop less than the meter reading gives good shadows, you EI is (when metering shadows where you wish to retain good detail) 4x the box speed (i.e. for 400 film you need to set your meter at 1600)

You have now fixed your personal EI but there is one more testing stage to go.

1. Find a scene with with a good range of tones
2. Using your EI, meter the brightest area in which you wish to retain highlight detail
3. Move the camera so that you are only photographing this highlight area
4. From the meter's reading open up the aperture by 3 stops or decrease the shutter speed by three stops
5. Expose the whole roll at this setting
6. In the darkroom, process one third of the film for recommended development time

7. When dry put negative in the enlarger and make a three section test strip exposing for half the minimum black time established earlier, for the established minimum black time and for double the minimum black time.
8. Process print and dry it.
9. If the section of the test strip exposed for 1/2 the minimum black time gives bright highlights with a trace of detail then the film requires 20% more development
10. If the section of the test strip exposed for the minimum black time gives bright highlights with a trace of detail then the film is correctly developed
11. If the section of the test strip exposed for double the minimum black time gives bright highlights with a trace of detail then the film requires 20% less development
12. You can use the rest of the exposed highlight test film to fine tune the development time.

YES - it is VERY boring but . . .for the investment of minimal materials and a few of hours you will have pinned down so many variables that it is really worth doing.

Back in the real world, all you need to do in future is meter the shadows that you wish to retain good detail with meter set at your EI and then stop down the aperture 2 stops or increase the shutter speed by 2 stops. In the darkroom start your first test print with the minimum exposure to achieve maximum black (inclusive of dry-down compensation) and go from there.

Best,

David
www.dsallen.de

David, I'm confused by steps 6 and 7. They both seem to be aiming to find the minimum printing time to achieve maximum black. It seems like you find the minimum printing time in 6 and then find it again in 7.

If I have followed correctly, the last frame of the 6-frame sequence (-3) is equivalent to Zone 0 if you assume that the meter is trying to get middle gray (Zone V). You started at a Zone V meter reading of the desired shadow area, stopped down 2 stops (Zone III) then an additional 3 stops to get to Zone 0. I can see where this would, as you said, include some density and include lens flare, etc. You then find the minimum print time for maximum black with this -3 stop frame. This makes sense to me. I don't understand why you then do this a second time with the first exposure. If you use this second time as the minimum time for maximum black, wouldn't exposures 4 and 5 be "blacker than black" given that they received less exposure than frame 1 and you used frame 1 to determine the minimum time for maximum black? Or, am I misreading your post?

Regards,
Rob
 

David Allen

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Hi Rob,

David, I'm confused by steps 6 and 7. They both seem to be aiming to find the minimum printing time to achieve maximum black. It seems like you find the minimum printing time in 6 and then find it again in 7.

If I have followed correctly, the last frame of the 6-frame sequence (-3) is equivalent to Zone 0 if you assume that the meter is trying to get middle gray (Zone V). You started at a Zone V meter reading of the desired shadow area, stopped down 2 stops (Zone III) then an additional 3 stops to get to Zone 0. I can see where this would, as you said, include some density and include lens flare, etc. You then find the minimum print time for maximum black with this -3 stop frame. This makes sense to me. I don't understand why you then do this a second time with the first exposure. If you use this second time as the minimum time for maximum black, wouldn't exposures 4 and 5 be "blacker than black" given that they received less exposure than frame 1 and you used frame 1 to determine the minimum time for maximum black? Or, am I misreading your post?

Sorry - should have made steps 6 and 7 clearer. The idea with step 7 is just to double check that you have correctly identified the right time for maximum black. I have found that many students are surprised that, when they add more time on the stage 7 tests they can visually identify that they have, in fact, not identified the correct time in stage 6 (i.e. by adding some more time on a test strip they can see a darker black than the time from stage 6 had suggested to them).

As you indeed rightly identified, it is important to use an 'exposed' frame rather than 'clear' film between frames as this is mimicking the 'real world' situation when making images (i.e. there will be in many images that contain a very dark area that should be printing as black - assuming that is the photographer's intention of course).

Hope this makes the testing sequence clearer.

Bests,

David.
www.dsallen.de
 

rbultman

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Thanks David, that is more clear. I still need to digest the second half of your process related to highlights. Pretty clear overall though.

Regards,
Rob

Sent from my Nexus 5 using Tapatalk
 
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Back in the 80's I started doing my own Zone System tests based on Ansel Adams method in "The Negative" and it's always worked well for me.

A little later I came across a slightly simpler approach which had come from Minor White workshops, and his assistants, to the UK, while the method was essentially the same the written explanation and methodology was clearer and simpler and made far more logical sens, But then Minor white pioneered the Zone systen with AA.

When it come to bos ISO/EI we need to be quite clear what we are after, Kodak for instance claimed Tmax100 was 100 ISO on its release yet in its (original) data-sheet suggest using it at 50EI for an improved Tonal range, As the Zone System is about control over the the Tonal range it makes perfect sense when personal testing indicated my personal EI for Tmax100 was 50EI, this matches Kodak and the tests John Sexton carried out and published (in Darkroom Technique) before Tmax films were publicly released.

So RobC, yes your correct the box EI is not necessarily the correct EI for all applications and Kodak made that quite clear in their literature.

Ian

Ian, it's not a question of what to set the EI at. Half the ISO is the pre-1960 standard. Uncontrollable variable such as flare, metering decisions, and the subject luminance range have a larger influence in exposure than whether to adjust the EI by 1/3 or 1/2 stop. The question is if a test is covering what it should and that it's actually producing good information, or is it potentially filled with experimental error. If the latter, is it worth the time and trouble to test?

Empirical evidence trumps Anecdotal evidence every time. Similar or the same results can be obtained by many different approaches, but that doesn't mean every method is sound. My favorite example is the picking of the mandrake root. In Medieval times, people anthropomorphize the root and believe it would scream when picked driving anyone who heard it insane or dead. So they came up with a very creative way to pick it. Conclusion, it got picked, but I think we can all agree the process was conceptually questionable.

The Zone System contains some major misconceptions. This is more about a metering techniques and not a claim the ISO speed is incorrect. Speed being based on reproducible density is one of them. It ignores the influence of flare on speed, the relationship between the metered exposure point and the speed point, and hold time to name a few. As Vizzini said in Princess Bride, "Wait until I get started." Shouldn't there at least be caveats with the step-by-step ZS instructions? Nobody can truthfully claim there isn't a huge potential for experimental error with the Zone System approach.

Notice that Kodak's "suggestion" didn't involve testing. Most general purpose developers achieve the ISO speed. Sexton promotes the Zone System so his tests are going to reflect the type of results from the testing method in question. Kodak's statements in the 80s began to reflect the public perceptions and common working practices. They used to say it's impossible to push for speed. Then they came out with P3200. What they were actually doing was written in small print. If I remember correctly, P3200 said that it will produce acceptable results at higher EIs if photographer can accept a slight loss in shadow detail.

I personally don't care if people store their film in cow dung for a day after exposure, or believe the Flintstone bird chisels the image onto the film, or they first need to pray. My concern is for people to be able to make an informed decision and not unquestioningly follow authority figures. But like Jon Steward said on this farewell show, he's been doing his thing for 16 years and Fox News is as strong as ever.

For me, the most important test is for film contrast.
 
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RobC

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The most important thing is to obtain a negative which is easy to print and NOT a target contrast value except that in by calibrating to a 10 stop range you have effectively done that but in the knowledge it will usually produce a slightly soft negative. And a slightly soft negative is very easy to print using VC paper.

Fact is the vast majority of people will never get into sensitometry and film testing anywhere near the level you have Stephen, so trying to ram it down their throats is an exercise in futility.

Whereas a relatively simple practical evaluation which produces a result they can judge visually is beneficial in confirming the EI they are using is correct or erring towards overexposure and that their development time is about right and how they are metering is actually producing what they think it should be doing. That is all achieved by the test I outline above and doesn't require any sensitometry maths, graphs etc.

And it automatically irons out your pet flare theory, a meter being off by a consistent amount and fators in lens extension, all things I have mentioned above. All in one simple test (which may need to be repeated a second time) and they don't need to worry about all minutia that you would have them worry about.

How about you write up your full test and validation procedure so that people can see which they would prefer to use. My bet is it will be a simple practical evaluation which trumps theory every time becasue it takes out or shows all the errors in the theory, equipment, materials and/or shows up all the operator errors which theory never can.

At the end of the day you are stuffed because most all cameras and lenses only work in 1/3 stops so any precision can only be to nearest 1/3 stop and that should always be targetted at nearest 1/3 stop on the over exposure side so can be a full 1/3 stop. So the precision is not possible in the equipment we use. Does that matter? Not a jot because because you can't tell the difference in the finsished print if the error was a tad on the over exposure side and the printer knows what they are doing.
 

Bob Carnie

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I find this thread timely as I have a youngish man wanting to up his game with film and printing..

He is working in the darkroom with me and going to then follow up with a three day printing with Steve Sherman...

Here is how we are preparing him for Steve, - I am lending him my 4 x5 sinar and he is going to load up a bunch of film. fp4- developer will be ID11- rather than pyro as we want to have some challenging negatives for printing with Sherman.

There is an alleyway in my back so this dude is going to photograph different scenes... white sheet in front of a white garage door in open sunlight , dark object in open shade, open light with black to white objects with low lighting range, mid lighting range, and high lighting range.

So you get the idea, some easy negs some super hard- I want to make Sherman's life hell.

In each case he will carefully bracket each scene with a 5 sheet spread- then load up 10 sheets at a time in the Jobo and process. Under each scene with various technical problems we will pick the
negative Visually that best represents the scene, and let Sherman figure out how to split print the suckers.

After Shermans visit , this young man will come back to my darkroom and show me a 16 x20 print by doing it in my darkroom by himself.. Hopefully he will get the message and learn a bit about the relationship between lighting ratio, and print contrast ratio. They are linked and both Sherman and I approach the printing process somewhat the same.

Steve has a complete regimen of negative development but for this project (the young dude has only worked with digital) we want to keep it simple but difficult.

After this step I would imagine some serious Ring Around tests with film and developer would be in order but seeing what a decent negative of different scenes is a fundamental step in any persons journey on film - printmaking.
 

Bob Carnie

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Not to be argumentative but if I am looking at a high contrast lighting ratio scene I will always go to PMK, for normal scenes it doesn't make a hoot of difference.

QUOTE=Michael R 1974;1953775719]ID-11 will do as any tanning/staining developer for recording information on FP4 regardless of the contrast range. It shouldn't really be more challenging to print, although perception is a powerful thing.[/QUOTE]
 
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The most important thing is to obtain a negative which is easy to print and NOT a target contrast value except that in by calibrating to a 10 stop range you have effectively done that but in the knowledge it will usually produce a slightly soft negative. And a slightly soft negative is very easy to print using VC paper.

Fact is the vast majority of people will never get into sensitometry and film testing anywhere near the level you have Stephen, so trying to ram it down their throats is an exercise in futility.

Whereas a relatively simple practical evaluation which produces a result they can judge visually is beneficial in confirming the EI they are using is correct or erring towards overexposure and that their development time is about right and how they are metering is actually producing what they think it should be doing. That is all achieved by the test I outline above and doesn't require any sensitometry maths, graphs etc.

And it automatically irons out your pet flare theory, a meter being off by a consistent amount and fators in lens extension, all things I have mentioned above. All in one simple test (which may need to be repeated a second time) and they don't need to worry about all minutia that you would have them worry about.

How about you write up your full test and validation procedure so that people can see which they would prefer to use. My bet is it will be a simple practical evaluation which trumps theory every time becasue it takes out or shows all the errors in the theory, equipment, materials and/or shows up all the operator errors which theory never can.

At the end of the day you are stuffed because most all cameras and lenses only work in 1/3 stops so any precision can only be to nearest 1/3 stop and that should always be targetted at nearest 1/3 stop on the over exposure side so can be a full 1/3 stop. So the precision is not possible in the equipment we use. Does that matter? Not a jot because because you can't tell the difference in the finsished print if the error was a tad on the over exposure side and the printer knows what they are doing.

It's a common mistake (or a straw man in your case which I believe is considered a logical fallacy) to assume that someone who speaks from a scientific position is claiming it's about achieving more precise results. It's not. it's about understanding the process and by doing so understand the expected variance of the process. Ever notice that scientific claims come with a lot of caveats? While Zone System practitioners are absolutely certain their true speeds are more accurate than the ISO. I understand the influences so I know what can be expected.

I've covered the incorporation of flare in testing in great detail. I think you have presented good example of how not understanding the concepts can lead to bad conclusions. This is science. You should be careful with the science denying stick. Just like with climate change and evolution deniers, it doesn't come off as smart.

My testing involves a sensitometer, exposure and tone reproduction theory. The conceptual details are in the Defining K document. But you probably haven't noticed that I don't try to impose my testing approach on anyone. Or that on this very thread I suggested using Kodak's recommendation as a way not to use sensitometry. The few times I actually make suggestions usually is about starting with the ISO, shoot, then make adjustments for your metering preferences. Why? Because I understand the process and the variables, but it's easier for you to create some imaginary control freak so you can "win" an argument (note: definition of straw man). Why not accuse me of supporting film death panels?
 
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Ansel Adams talks about flare cheerfully as he examines the beach shot...

"A little camera flare helped the shadow density as expected" around 8:10 into the video

https://www.youtube.com/watch?v=M-BhJQqHXfQ

Maybe so Bill, but it's not dealt with correctly in the ZS testing. Since Zone System uses metered exposure and stops down, as well as filling the frame with a uniform target, there is little flare present in the test. What's ironic is that this is actually a good thing. What's bad is that flare isn't later incorporated into the speed determination like it is with the ISO standard. As I've previously shown (and I think it might be in the Defining K document) there is only about 3 percent flare at the metered exposure point under an average luminance range. Average flare in the shadows is around 1 to 1 1/3 stops average. Kodak uses the 1 1/3 stops which correlates more with 35mm uses. They changed from 1 1/4 as they moved from the larger format flare. This is the reason for the shift from CI 0.56 to 0.58 as their normal.
 

Bill Burk

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My testing involves a sensitometer, exposure and tone reproduction theory.

Maybe we should discuss these ideas in a thread with a different title. It's clear you and I hold the opposing position.

This thread should hold thoughts how to do it without sensitometry.

To that aim I have designed a simple test that can provide sufficient clues to your contrast, in two frames of film.

1. Aim your camera at a flat-toned subject such as a wall lit by direct sunlight.
2. Shoot one frame at the recommended meter reading.
3. Open up two stops and shoot that same wall again.
4. After developing, look at the negative with a light meter.

If the meter shows that the first frame differs from the second by one f/stop...

Then you have a contrast of about 0.50

That's a reasonable contrast for Zone System "N" Normal.
 

Bill Burk

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Maybe so Bill, but it's not dealt with correctly in the ZS testing. Since Zone System uses metered exposure and stops down, as well as filling the frame with a uniform target, there is little flare present in the test. What's ironic is that this is actually a good thing.

Yes it's a good thing, because Ansel Adams film tests reveal the speed point.

I agree, Ansel Adams didn't explain flare in his systems, so we find that he understood it intuitively in that video. It would be great if he had figured out how to work flare into the Zone System. He really struggled to understand K
 

Bill Burk

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How about you write up your full test and validation procedure so that people can see which they would prefer to use. My bet is it will be a simple practical evaluation which trumps theory every time becasue it takes out or shows all the errors in the theory, equipment, materials and/or shows up all the operator errors which theory never can.

I wrote up my thoughts and posted them here:

(there was a url link here which no longer exists)

I won't bet on which method will be what people will use.

For reasons that I don't understand, people continue to test by shooting 20 rolls or 50 sheets (recommended in The New Zone System Manual by White, Zakia, Lorenz), when they could spend six dollars on a Stouffer step wedge and expose 5 sheets under an enlarger.

I also recommend a test that consumes two shots of film. Haven't heard many people adopt that idea either.
 
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Maybe we should discuss these ideas in a thread with a different title. It's clear you and I hold the opposing position.

This thread should hold thoughts how to do it without sensitometry.

Agreed. I was answering a question. I did post a suggestion that doesn't use sensitometry. I do think it's important to point out that just because the thread is about testing without sensitometry (even though it's part of the whole design process), I don't believe it legitimizes science bashing.
 
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RobC

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It's a common mistake (or a straw man in your case which I believe is considered a logical fallacy) to assume that someone who speaks from a scientific position is claiming it's about achieving more precise results. It's not. it's about understanding the process and by doing so understand the expected variance of the process. Ever notice that scientific claims come with a lot of caveats? While Zone System practitioners are absolutely certain their true speeds are more accurate than the ISO. I understand the influences so I know what can be expected.

I've covered the incorporation of flare in testing in great detail. I think you have presented good example of how not understanding the concepts can lead to bad conclusions. This is science. You should be careful with the science denying stick. Just like with climate change and evolution deniers, it doesn't come off as smart.

My testing involves a sensitometer, exposure and tone reproduction theory. The conceptual details are in the Defining K document. But you probably haven't noticed that I don't try to impose my testing approach on anyone. Or that on this very thread I suggested using Kodak's recommendation as a way not to use sensitometry. The few times I actually make suggestions usually is about starting with the ISO, shoot, then make adjustments for your metering preferences. Why? Because I understand the process and the variables, but it's easier for you to create some imaginary control freak so you can "win" an argument (note: definition of straw man). Why not accuse me of supporting film death panels?

I started a topic on zone system calibration without the need to use sesitometry. I suspected that what would happen has happened. All the sensitometrists come crawling out of their holes are start quoting their way of doing things. Thats why people find it all so confusing, no one can write a pratical evaluation method method for doing it without the pinheads saying they know better. Tell a scientist they are wrong and they get high and mighty about it. They can't take criticism.

Some of them have some common sense. Take Konrad Lorenz for example, he is quoted to have said:

"Every man gets a narrower and narrower field of knowledge in which he must be an expert in order to compete with other people. The specialist knows more and more about less and less and finally knows everything about nothing."
 

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I was advised by a good mentor early that an expert was one who knew and ounce more information than me on any particular subject and used that advantage to knock the crap out of me.

It seems this thread was about a practical method of finding ones way without resorting to sensitometry.
 

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I started a topic on zone system calibration without the need to use sesitometry. I suspected that what would happen has happened. All the sensitometrists come crawling out of their holes are start quoting their way of doing things.

Hopefully I've respected the spirit of your thread. I know I hold an opposing position, but I don't want to detract from your message.

What I believe is happening "today" is that we haven't talked about Zone System in a while, we love talking about it, and a few recent threads have revived an interest. To that end, I'm happy we are actively discussing it.
 
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I started a topic on zone system calibration without the need to use sesitometry. I suspected that what would happen has happened. All the sensitometrists come crawling out of their holes are start quoting their way of doing things. Thats why people find it all so confusing, no one can write a pratical evaluation method method for doing it without the pinheads saying they know better. Tell a scientist they are wrong and they get high and mighty about it. They can't take criticism.

Some of them have some common sense. Take Konrad Lorenz for example, he is quoted to have said:

Except for the post where I was talking to Bill in a language we both understand, I haven't used sensitometry, unless you think the Flintstone reference is sensitometric. If you read that paragraph, you will see that I said I don't care about anybody's process. How is that cramming sensitometry down people's throats? Pease stop misrepresenting my position. You are just being defensive because I pointed out some short comings of something you support - ie Zone System. I also proved your statement about the 30% development reduction wad erroneous and instead of being able to defend your position, you're having a childish fit.
 
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Here is a quote by John Sexton from A few ideas on using Kodak T-Max Films Successfully

"As with most black and white negative films I used an Exposure Index (El) that is less than the manufacturers' suggested film speed. T-MAX 100 and 400 were both initially tested by the Kodak laboratories in D-76 developer, and performed exceptionally well in this developer."

This simply conforms to the fact that Zone System testing methodology is different than ISO. And just to be absolutely clear, there isn't anything wrong with rating a film differently than the ISO. Just because I am pointing out that there is a difference between the two methods, only means that it is an important distinction.
 

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I have always suggested that negative films can be overexposed by 1/3 to 1/2 stop. That has been posted and quoted here several times. It is an easy way to get better images in most situations.

PE
 

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I have always suggested that negative films can be overexposed by 1/3 to 1/2 stop. That has been posted and quoted here several times. It is an easy way to get better images in most situations.

PE

HiRon

So what were we doing before 1961 and the ASA changes?

Noel
 

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...and the speeds John used at the time (with D-76) are in line with the expected difference between ZS and ISO (ie 2/3 stop). He was rating TMX 100 at 64 in D-76 at the time. TMax/TMax RS Developer, being a typical PQ formulation, gave slightly higher speeds. XTOL had not come onto the market yet but would also produce slightly higher speed than D-76. These differences are very small, however.

This is why I'd suggest if one wants to get a Zone System-style EI for most general purpose film/developer combinations, never mind no densitometer, no testing at all is required. ZS-style tests will end up somewhere between 1/2 and 1 stop lower than ISO every time, and even without considering flare (since we're talking ZS EI), anything smaller than 1/2 stop is false precision anyway. So simply cut the ISO speed in half, and there's your Zone System EI. No sensitometry, no equipment, no test films.

Well I use -4/3 of a stop from EI/ISO I'm not worried about overexposing my zone 1 by 1/3 and cloud and sunlight are like witches, they tend to burn anyway.

I use recommend times for 0.55~0.6 gamma.
 

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So where are we all on base plus fog... does a print suffer from having a higher base density?
 
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