D-76 shelf life

relistan said:

My answer, and a few others was "test it". So IMO an answer one way or the other is not necessary.

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I will still give up on this one, relistan because I get a strong message from some quarters( not including you) that I should give up

However you deserve a reply. What you have suggested is what I believe to be the best course of action as well but I was attempting to put myself in the OP's shoes. He has done something that is new to him and he was asking for advice

I just feel that simply telling him either it's fine to use or a certain disaster to use without evidence or personal experience of disaster in circumstances similar to what he quoted may not be as helpful as it is possible to be

I still cannot see why "testing" runs risks so I asked for those who are against this route to say what evidence there is that makes them say it is not even worth testing

To use a bad pun on a photography forum, there seems to be more and more threads that result in either black or white responses and this is a pity in my opinion

pentaxuser

I mixed up D-76 1+1 (years ago in Japan), and forgot about it... There it sat in the beaker over night in 35C heat and humidity. I stuck a discarded piece of HP5 sheet film in, and it developed, but way below Dmax. If yours is stored in a full capped bottle, with no air, I'll bet it's okay... but why chance it?

Don't give up.
But if you can figure out a way to reliably test the behavior of a single litre of 48 hour old 1+3 diluted D76 without either using it up by developing a whole roll of film to do the test or employing a step wedge, a clip, and a densitometer, I'll be happy to change the recommendation .
One of the things that is most challenging to attain when you are relatively new to this stuff is a sense of the relative importance of all the factors involved. In this case, weighing the value of a small amount of relatively inexpensive developer (that is known to deteriorate fairly quickly - even if slightly unpredictably - over time) vs. the value of the roll of film (including the related, time, effort and opportunity) leads inextricably to the conclusion that the OP should use fresh developer for that film.
If the OP wants to waste a separate, test film for the purposes of an experiment, I'd suggest exposing that test film, cutting it in half, and then do two development runs. One run of the OP's current film and half the test film in fresh developer, and one run of the other half of the test film in the 48 hour old developer. Then compare the results between the two halves of the test film.

pentaxuser said:

I will still give up on this one, relistan because I get a strong message from some quarters( not including you) that I should give up

However you deserve a reply. What you have suggested is what I believe to be the best course of action as well but I was attempting to put myself in the OP's shoes. He has done something that is new to him and he was asking for advice

I just feel that simply telling him either it's fine to use or a certain disaster to use without evidence or personal experience of disaster in circumstances similar to what he quoted may not be as helpful as it is possible to be

I still cannot see why "testing" runs risks so I asked for those who are against this route to say what evidence there is that makes them say it is not even worth testing

To use a bad pun on a photography forum, there seems to be more and more threads that result in either black or white responses and this is a pity in my opinion

pentaxuser

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Cannot speak for others, but one should ask some questions about any "test." Off the top of my head (1) what question is the test designed to answer; (2) how will the test be designed to ensure that its results are meaningful and repeatable by others; (3) is the test and its results generalizable, and if so, under what circumstances; and maybe I should have specified upfront, (0) Has the question/test been done by others?

Now this said, I had no intent of stifling the OP's desire to investigate and learn. And, I am hopeful that others who are chemists might read this thread and provide some additional insights into some "general questions" related to the OP's original question.

MattKing said:

Don't give up.
But if you can figure out a way to reliably test the behavior of a single litre of 48 hour old 1+3 diluted D76 without either using it up by developing a whole roll of film to do the test or employing a step wedge, a clip, and a densitometer, I'll be happy to change the recommendation .

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OK Matt you've persuaded me- I won't give up Firstly are you saying the exposed leader test for testing developer is useless? If so then there is no point in my continuing and we can just "beg to differ"

However I will give you my reasoning for my endorsing the testing of the 48 hr old 1+1 D76 as a "nothing to lose" strategy

The time for a 1+1 fresh dilution to develop film X is a known so using that time the OP uses the short exposed leader and develops for that time. This can be done in the daylight and with relatively little of the diluted 48hr old 1L of D76

The leader being exposed should turn a deep black i.e. should look like a leader developed in fresh 1+1 D76. OK how does he judge this black if he has not kept any previously developed leaders from fresh 1+1 or indeed fresh full strength stock with which to compare?

That does give him more of a problem than comparison with a leader developed in fresh developer although it is largely the same problem I posed to Don Heisz who described a test for unknown film which was wait until it goes black and double the time. It involves some judgement as to what "black"is

When I test Xtol stored in a winebag for a while I use the incandescent clear bulb filament test If I can see the filament as a clear orange strand then I found that the developer was still giving me OK negatives from which I could see little or no difference from the Xtol that was new, The same black leader give me a very dark looking outside scene in which there was little detail when held up to a window

On the above Xtol test I will now say that I became a little wary of using it when the stock had turned from water white to the palest of straw colour and I mentioned this in a thread to which you replied. I mentioned that I thought that the leader in that test had allowed the filament to appear slightly brighter and it was you, if I recall correctly that said you thought the Xtol to be OK but to be on the safe side I should develop the film for a bit longer

So yes some judgement is called for on the part of the OP but it seems to me that if the 48 hr 1+1 D76 gives him a slightly less black leader then if my experience is anything to go by he will still have negatives that are OK to darkroom print or scan and print and he will lose nothing if he adds a bit on to the recommended development time

Will he have the prefect negative or the perfect print, possibly not as indeed neither might I have gotten the perfect negative using older Xtol but I did get perfectly usable negatives that gave me usable prints that I am happy with

If I may say so this whole unbridgeable divide between the "dumpers" and "testers" seems to be less about the testers inviting the OP to pursue a course that inevitably leads to almost certain disaster and more about avoiding anything which might be sub optimal in the slightest. That is a discussion that will always generate 2 opposed parties and on which there is no end except to agree to differ.

I cannot speak for the other "testing" advocates but in making my suggestion I was driven by what I thought was a desire by the OP to find out if there was any way to check if his 48hr dilution was OK

I had assumed that if he was 100% risk averse then he might have simply dumped the 48hr 1+1 dilution and never bothered to ask the question. Believing he wanted to find out if there was any chance his liquid was usable to the extent of giving his negatives a real fighting chance I advocated leader testing as it had worked for me

I interpreted( may be wrongly) from his last post that he had decided against testing and of course by then and certainly by now his several days older 1+1 D76 becomes more problematical in terms of its efficacy

As long as I can remember I will try on the next occasion when a similar thread arises to ask how important it is for the OP to be 100% sure of doing everything to ensure there is not even the slightest risk to the film

If the reply is that a 100% certainty of perfectly developed negs is required then I shall at least point out that 48hr old diluted D76 may carry some risks

pentaxuser

pentaxuser said:

Firstly are you saying the exposed leader test for testing developer is useless? If so then there is no point in my continuing and we can just "beg to differ"

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Not useless - it shows you whether or not the developer is dead. If it is dead, the test is useful indeed.
But if its activity level has been reduced, a piece of leader may still come out fully black, whereas a properly exposed negative may come out so under-developed as to be almost useless. Alternatively, it may come out so low in density as to give really lousy results, no matter what workflow you use. You can't tell which. Will the OP be happy taking that risk with his film and the exposures on it?
Exposed leaders are incredibly over-exposed - many, many, many stops of extra light. For testing purposes, the only reliable test using them is a death or life experiment.

Last time I suspected a batch of film developer had lost some activity I made a new batch and compared the old and new. Instead of film I used small pieces of photographic paper. Film developer is weak compared to paper developer but it does develop paper ... eventually, sort of. With two small trays of new and old developer drop some medium exposed paper pieces in and watch what happens under safe light. Differences, if any, are obvious in minutes.

MattKing said:

Not useless - it shows you whether or not the developer is dead. If it is dead, the test is useful indeed.
But if its activity level has been reduced, a piece of leader may still come out fully black, whereas a properly exposed negative may come out so under-developed as to be almost useless. Alternatively, it may come out so low in density as to give really lousy results, . You can't tell which. Will the OP be happy taking that risk with his film and the exposures on it?

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So was I just lucky in my Xtol leader test if it is the case that a leader may come out fully black but result in useless negatives and have the other advocates of testing been similarly lucky?

However if you are right that a fully black leader gives no indication whatsoever of how well the developer will be able to develop the film i.e. it is an established fact then on our forum this should be stated as an established fact for future reference

If on the other hand it is a possibility, be that low medium or high then that should be stated also . Depending on how high the likelihood is, each person in the same situation as the OP is then in a position to decide if he uses the black leader test or not

I have to say that short of there being evidence of the probability of the test's success and given the number of testing advocates I remain unconvinced from this and my own testing that the leader test is useless at other than determíning that there is some life left in a developer and that "some life" in the form of producing a deep black, the definition of which I gave, is useless at predicting the outcome for the actual negatives. If this is genuinely and incontrovertibly the case then I would then say why bother to even use the test if all it tells us is nothing that is of practical use. It simply wastes time compared to pouring the dilution down the drain

There are clearly those who cannot understand why if there is less than a 100% certainty that 48 hr diluted 1+1 D76 will work as perfectly as 15 min D76, why anyone should want to use it. I understand their stance on this but we are back to the spectrum of risk aversity as I mentioned

However if there is hard scientific evidence that there is no correlation between a black leader and OK negatives then can this be shown to us so in future we can refer to it each time such a thread arises. It is in all our interests that we do not use a test that bears no relation to negative outcomes

pentaxuser

I’ve used D-76 since childhood so I know stock lasts “forever”, but I am also familiar with the advice to use promptly after dilution.

One could quantify the degradation by running two tanks with sensitometry tests on a roll in each tank. One tank fresh and the other with “diluted a couple days ago.”How the curves match up will reveal the degree of degradation.

My favorite hunch is… it’s probably 30% less effective.

An exposed leader test with diluted D-76 is not reliable.
It may be more reliable with stock X-Tol, because X-Tol has more of a tendency to die suddenly than diluted D-76.
But if I only had enough developer left to develop one or two rolls, I wouldn't risk them.

By the way, an exposed leader test returns one of three possible values:
1) black leader;
2) grey leader;
3) clear leader.
2) and 3) are obvious "negatives". You can't reliably tell whether 1) is a true "positive", or a false "positive", without further testing that will use more developer and more film.
With a black leader, the ratio between false "positives" and true "positives" will vary with types of developers and dilutions.

Bill Burk said:

I’ve used D-76 since childhood so I know stock lasts “forever”, but I am also familiar with the advice to use promptly after dilution.

One could quantify the degradation by running two tanks with sensitometry tests on a roll in each tank. One tank fresh and the other with “diluted a couple days ago.”How the curves match up will reveal the degree of degradation.

My favorite hunch is… it’s probably 30% less effective.

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Sounds like an interesting experiment, Bill but not one I am equipped to do. I would be amazed if Kodak didn't do experiments on this to determine what the safe time margin was for diluted developer.
I have no idea what words Kodak uses to indicate "safe time" but interestingly Ilford does give a time of not more than 24 hours for ID11


pentaxuser

The Kodak D-76 datasheet says:
"If you use Developer D-76 diluted 1:1, dilute it just before you use it, and discard it after processing one batch of film. Do not
reuse or replenish this solution."

MattKing said:

The Kodak D-76 datasheet says:
"If you use Developer D-76 diluted 1:1, dilute it just before you use it, and discard it after processing one batch of film. Do not
reuse or replenish this solution."

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With respect,Matt, that tells us nothing that we don't already know. Ilford in the earlier part of its info sheets on ID11 says to prepare "dilutions immediately before use" as well but goes on say do not use more than 24 hrs later so,it seems to offer a time limit

If it says 24hrs later then the question is: What has happened in the ensuing 24 hrs?

I doubt this means that at 23 hrs 59 mins it will be perfect and at 24hrs 1 min it will be useless. I'd have thought that that same applies to D76 or any other developer. It deteriorates over time, However if 24 hrs is the time beyond which Ilford suggests ID11 should not be used it suggests to me that up to 24 hrs the deterioration is marginal enough that users will get usable negs

So key here is what might be the time within which D76 still produces usable negs which if I were Kodak or Ilford I'd determine negs that will still produce acceptable prints

Bill has kindly "stuck his neck out " and estimated that the deterioration over 48 hrs is 30%. This leaves the 2 questions:
1. What might the actual deterioration be over 48 hrs
2. Can deteriorations be compensated for by increasing development time and if so over what time period

It seems to me we all have opinions but no-one has the answers to the above 2 questions

pentaxuser

pentaxuser said:

ill has kindly "stuck his neck out " and estimated that the deterioration over 48 hrs is 30%. This leaves the 2 questions:
1. What might the actual deterioration be over 48 hrs
2. Can deteriorations be compensated for by increasing development time and if so over what time period

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Why would anyone risk their film to determine this in the interest of saving 250ml of stock D-76 that has been sitting out, diluted to a non-standard dilution, for 48 hours?
EDIT: That is enough to develop a single roll of film (in a 1+3 dilution).
And as 1 + 3 is not a dilution recommended by the manufacturer - so Eastman Kodak and Kodak Alaris wouldn't have been likely to research the question in the past, and Sino Promise wouldn't be likely to research it now.
If someone wants to examine the behaviour of the recommended dilution of 1 + 1, and was willing to do research into greater quantities than enough to develop a single roll, go ahead, but it doesn't seem to make much sense with D-76.

I’d do it because I am curious. I could just tray develop a strip, it wouldn’t waste much film.

Thanks Matt but I gathered that this was yours and several others' opinion quite a while ago. I am still curious as is Bill and it is this curiosity that I has hoping to satisfy but I am sure you have worked this out as well

pentaxuser

Bill Burk said:

I’d do it because I am curious. I could just tray develop a strip, it wouldn’t waste much film.

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Thanks, Bill

pentaxuser

I have no problem with the curiousity, and would be intrigued by the result of what he proposed.
My posts are more about what should be done with the results. And in general about what tests can tell you, and what they can't tell you.
IMHO, a single positive result shouldn't be enough for the OP to risk a roll of film on it - particularly when there is only enough developer in that litre to develop a single roll of film. The amount used to do the test would decrease the developing capacity of the litre.
Even if there were 4 litres of 1 + 3 diluted developer there, and the opportunity to do a number of tests, I don't think such a non-standard dilution left to stand for a non-standard period of time could ever lead to test results that one could rely upon.
Telling an OP to "test" the developer only works if there are tests that can give results that are worth risking exposed film on.

MattKing said:

I have no problem with the curiousity, and would be intrigued by the result of what he proposed.
My posts are more about what should be done with the results. And in general about what tests can tell you, and what they can't tell you.
IMHO, a single positive result shouldn't be enough for the OP to risk a roll of film on it - particularly when there is only enough developer in that litre to develop a single roll of film. The amount used to do the test would decrease the developing capacity of the litre.
Even if there were 4 litres of 1 + 3 diluted developer there, and the opportunity to do a number of tests, I don't think such a non-standard dilution left to stand for a non-standard period of time could ever lead to test results that one could rely upon.
Telling an OP to "test" the developer only works if there are tests that can give results that are worth risking exposed film on.

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Matt I believe there are a number of counterpoints to the above, some of which I thought I had mentioned but we really have come to the end of a useful debate between us on this in the sense that is not likely to reveal any further useful discoveries.

When and if he has the time, then what Bill says he may attempt, as he is also curious, may reveal more useful information

There is a lot of stuff that we still don't know as established facts about matters of film photography and I am hoping that it is only by experiments that we can extend our knowledge


pentaxuser

I would propose testing D-76 1:1 as fresh, 24 hours, 48 hours and a week. I don’t know if I want to do 1:2 and 1:3 and I am sure DocW already developed his film…

You know, Edwal published development times by film class, temperature and count of film put through a batch.

It seems ridiculous to me to try to predict what would happen by the tenth film, but they did it anyway.

Bill,
Both Kodak and Ilford give recommendations for extending development as the roll count mounts for stock developers - like D-76.
Re-use of stock developer seems much less problematic than unusual use of developers that are used at much higher dilutions than are recommended.
As may be obvious, some developers are designed to be diluted - sometimes significantly and over a wide variety of dilutions - while others are designed to be used at or near a standard dilution. Some developers are quite robust when highly diluted while others deteriorate quickly when diluted. HC-110 is an example of the former and, I would suggest, D-76 is an example of the latter.

Thanks MattKing,

Keeping one-shot developers after mixed was never part of my plan.

I do expect rapid deterioration, like when you put Dektol in a tray.

But not instant degradation like lith developer after mixing A and B or Farmers reducer.