hypo check: what am i looking for?

PE,

Sorry to see you bow out. I hope my confusion and curiosity was not a factor in your decision. I simply was having difficulty reconciling the conflicting fixing times and capacities from different reputable sources: Ilford, Kodak, Gudzinowicz (and through his article, Haist). My suggestion that there might have been an error in the tables Gudzinowicz quoted was based solely the coincidental factor of approximately 4 between Kodak's and Ilford's capacity recommendations and those in the tables, even for commercial standards. This seemed to suggest a gallons-liters mislabeling. I guess I'm convinced that this is not the case.

I do clip tests and color-comparison residual silver tests, so I guess I'm alright. I still do not why the recommendations are so different. I was hoping for some enlightenment as to the reason(s). Perhaps there are no easy capacity guidelines for either film or paper, and manufacturers simply give averaged recommendations with a generous safety factor built in.

I'll keep reading and trying to understand the complexities of this issue more, and will always welcome your comments and expert opinions.

Best,

Doremus Scudder

Doremus, from what I remember and I think Ron (PE) is aware of it too, much of the Kodak research into fixers and washing was carried out by G.I.P. Levenson at Kodak's harrow Research labs (UK). Levenson worked as editor for L.F.A. Mason's Focal Press book, Photographic Processing Chemistry. Mason was Levenson's counterpart at Ilford.

One thing often missed is that the Kodak fixer tests were based on an Acid hardening fixer and Ilford's later tests with a Rapid fixer with no hardener. The consequence is the two sets of results are not comparable. There was a long heavily moderated acrimonious thread about this on Photonet a few years ago, it took Roger Hicks to point out the miss-assumptions and the facts that the Ilford recommendations are fully archival IF you use their fixers.

So research based on Sodium Thiosulphate hardening fixers isn't applicale to an Ammonium Thiosulphate unhardened fixer.

Ian

Ian is correct in all regards. There were also acrimonious exchanges here on fixation and washing and a number of us are barred from those threads. I didn't want this one to go that way. I just wanted to put forth the only practical way to make a measurement using YOUR individual work flow and materials.

Now, I am done.

PE

Ian, that bit of information is what Doremous and I were looking for. It explains the discrepancies of the units used. It had me confused for a long time until I just settled on using the leader test. But, knowing WHY the units used is based in the type of fixer used makes a lot more sense, simplifies the problem and resolves much of the conflicting views of what was just discussed. It's a good thread. It seems the assumptions of those differences between fixer types is 'known' by a lot of people, but Doremous and I aren't in that group - thus the questions/doubts of understanding and concern of "am I doing this right?"

Thanks.

Shadowtracker said:

Ian, that bit of information is what Doremous and I were looking for. It explains the discrepancies of the units used. It had me confused for a long time until I just settled on using the leader test. But, knowing WHY the units used is based in the type of fixer used makes a lot more sense, simplifies the problem and resolves much of the conflicting views of what was just discussed....

Click to expand...

Where did Ian say anything about units? I must have missed it.

RalphLambrecht said:

Where did Ian say anything about units? I must have missed it.

Click to expand...

I didn't but things like fixing times, wash times and silver levels in fixer are all figures/units quoted and the Kodak Research Haist quotes is based on Levenson's work and not appropriate for the mush later Ilford Rapid fixers where work was done by Mason and others.

Early rapid fixers were Sodium Thiosulphate/Ammonium Chloride based until the cost of Ammonium Thiosulphate dropped significantly in cost as demand rose.

Some writer failed to realise the huge differences in the types of fixers and then wrongly dismissed Ilford's research and recommendations for archival processing. Solubility of the intermediary complexes differ, the shorter fixing time help as well.

Ian

Ian Grant said:

I didn't but things like fixing times, wash times and silver levels in fixer are all figures/units quoted and the Kodak Research Haist quotes is based on Levenson's work and not appropriate for the mush later Ilford Rapid fixers where work was done by Mason and others....

Click to expand...

I understand that, but how does that clear up an alleged discrepancy of units used in Gudzinowicz's paper for Tim? There is no discrepancy. I'm afraid, he is reading something into your post.

It clears things up for me because I don't usually work with converting US to Metric measures. The fact that the data is written in two different approaches and with two different kinds of fixers makes sense to me now whereas it hadn't before. What Ian explained is that using a hardening fixer and a non-hardening fixer is where the differences stem from. Because I'm not an engineer working with these things on a daily basis, I wasn't aware that the data may be saying the same thing but in reference to two different kinds of fixers. I don't think I'm reading anything into Ian's post, though I probably shouldn't have included Doremus in my reply about Ian's making things clearer for me. I don't pretent to be a math major - Ilfords approach is when using their non-hardening fixer and their numbers work for their fixer; Kodak uses a hardening fixer and their numbers work for their fixer. For dweebles like me, the difference between the fixer types was not known until Ian explained that.

Tim

Ian is spot on with his remarks about the different fixers, but that has nothing to do with the units or measuring systems in Haist's report. By the way, I don't think Ian said that or meant to say that. I don't even think, he used the word 'unit' in his post. As Ian explained, Haist was assuming one type of fixer but used two types of units.

Are you are assuming that Ilford is using metric units and Kodak is not? That is not so!

Gudzinowicz and Haist are US scientists, and scientists around the globe are trained in metric units. They use them for their measuring systems. Measuring residual silver values in g/l is common practise, at Kodak and at Ilford. All Haist did was turn his metric measurement results into fixer capacities, US customers would be more comfortable with. That's why he used 8x10s/gallon for fixer capacity. He did not do that because of the difference between fixers. He translated research data into consumer data. That's all.

There is no mixup or discrepancy of units or measuring systems in his report.

Any Type

RalphLambrecht said:

As Ian explained, Haist was assuming one type of
fixer but used two types of units.

Click to expand...

ANY TYPE of fixer and at ANY dilution. Volumetric silver
limits are Haist's ONLY concern. Dan

dancqu said:

ANY TYPE of fixer and at ANY dilution. Volumetric silver
limits are Haist's ONLY concern. Dan

Click to expand...

That wasn't the point. I'm trying to address the false assumption that Haist made a mistake in units.

RalphLambrecht said:

Tim

Ian is spot on with his remarks about the different fixers, but that has nothing to do with the units or measuring systems in Haist's report. By the way, I don't think Ian said that or meant to say that. I don't even think, he used the word 'unit' in his post. As Ian explained, Haist was assuming one type of fixer but used two types of units.

Click to expand...

It has everything to do with it if we look at the data and assume he was talking about rapid fixers - even while ignoring the entire gallons vs litres aspect.

This is what the crux of the entire thread is about. There should be clarity here in resolving a good baseline set of numbers by which people can have a rough framework to go off of. "Use test-strips and leader tests every time you fix paper" is not going to fly with most people.

This thread really shouldn't be this difficult. People are just looking for pragmatic guidelines. Had Ian not jumped in and point out the part about standard fixer vs rapid fixers, some people may have assumed they should dump a gallon of rapid fixer after developing 4 rolls of film. Surely that should be CLEARED UP so people aren't wasting massive amounts of fixer (and money) because they think it's not archival anymore.

Ok, I bowed out, but this is going awry!

Grant used metric at EK but published data in English units (US not Imperial) for the sake of US customers.

OTOH, there is NO QUANTITATIVE DATA on fixing and washing. It must be determined for each case and you seem to be ignoring my posts on this. You must do a test for your own film/fixer/wash/local water for the results to be definitive.

Grant's last work and that of others was in the 70s and early 80s. Much was done after that to show that a lot more could be done. Think about this a bit and then consider what I posted earlier.

Only you can determine the right conditions for your work flow. I cannot, Ralph cannot and Ian cannot. We can only approximate!

PE

Exactly

Photo Engineer said:

Grant used metric at EK but published data in English units
(US not Imperial) for the sake of US customers. PE

Click to expand...

Exactly. Just what I was thinking. The fellow was/is
bilingual. Dan

clayne said:

It has everything to do with it if we look at the data and assume he was talking about rapid fixers - even while ignoring the entire gallons vs litres aspect...

Click to expand...

Clayne

There is no mistake in Haist's data. He did not mix up units.

You are shocked about his values for single-bath fixing and think he made a mistake? You should be shocked, because he did not make a mistake. You think he proposes to dump the fixer after two rolls of film? Please allow a different conclusion. In my view, Haist does not suggest to dump a gallon of fixer after two rolls of film. He suggests to not use single-bath fixing if you are interested in an archival workflow, and he shows how efficient two-bath fixing is in comparison.

Ian's post highlights important differences between fixers, but he does not agree that Haist used the wrong units. Ian and PE correctly point out that the only way to do this right is to test your own materials.

If this does not do it, I'm afraid, this thread has reached the limits, inherent to written communication. One would need to a discussion on Skype, or similar, to continue and clarify the statements made.

dancqu said:

Exactly. Just what I was thinking. The fellow was/is
bilingual. Dan

Click to expand...

Dan

Yes, I believe it's that simple. By the way, when I said 'imperial units' I meant inches and gallons, rather than metric units as in grams, mm and liters. I did not know that there is a difference between imperial and US units, other than different quantities for gallons for example. I went by this definition:

imperial |imˈpi(ə)rēəl|
adjective
...
2 of, relating to, or denoting the system of nonmetric weights and measures (the ounce, pound, stone, inch, foot, yard, mile, acre, pint, gallon, etc.)

Is that wrong?

We must distinguish between the US Gallon and the Imperial Gallon which are not equal. Grant used the US Gallon in some publications but internally he used Metric. Harrow used Imperial Gallons in some publications but Metric internally.

There was a lengthy exchange on this discrepancy on APUG some time ago, due to the confusion it created.

PE

With more that a little trepidation, I'll venture another post in this thread. It seems only fitting, however, since I was the one who hijacked it in the first place.

First a clarification: I limited my question to Kodak materials and recommendations compared with the tables from Haist quoted in Gudzinowicz to be reasonably certain I was comparing apples to apples. While I greatly appreciate Ian's remarks about the differences between fixer types and agents (they are quite enlightening and useful), I have enough technical and scientific background to at least try to avoid mistakes in procedure like making inappropriate comparisons. My question was, to the best of my knowledge, about different capacity numbers for the same fixer. I still think I am safe in assuming that good old Kodak packaged F-5 hardening fixer is what Haist's tables apply to. The reason for my question was first curiosity and second a desire to ensure the effectiveness of my processing.

In the same vein, my first post (which was a question and not an assumption in any way) addressed only capacities for "commercial" levels of fixation. I did assume that Kodak's published capacities for its packaged fixer were for "commercial" standards and for single-bath fixation. These capacities still did not agree with Haist's numbers (at least in the tables from the Gudzinowicz article); the discrepancy was approximately a factor of four (100 8x10 per gallon as opposed to 25 8x10 per gallon respectively). This led me to conjecture (mind you, only a conjecture, not an assumption, assertion, etc.) that there may have been an error in units "translation" at some stage, either in the preparations of Haist's material for publication or in their transference to Gudzinowicz's article. I must state here that my only access to Haist's numbers was from the Guduzinowicz article linked to earlier in this thread. I had no way to corroborate the quoted data conveniently at hand, hence my question.

It seems rather certain now that Haist's numbers are those he intended. The discrepancy between his recommendation for fixer capacity for commercial quality fixation and Kodak's published numbers for their packaged fixer product remains, however. I am still curious as to the reason. Perhaps the fixers in question are indeed very different, and my original assumption is false, perhaps they are based on two different standards for residual and dissolved silver, perhaps there is yet another factor in play here that I am not aware of.

Neither has my question about the discrepancy in recommended fixing times been addressed. As I mentioned earlier, Gudzinowicz recommeds 4x the clearing time for films. Anchell/Troop in one of their publications recommend 3x the clearing time for modern films. PE, you seem confident that 2x the clearing time is adequate. My curiosity about this discrepancy remains as well.

I wish to express at this point that I very much value the opportunity this forum gives me to have first-hand access to the knowledge and opinions of experts in the field such as PE, Ralph Lambrecht, Ian Grant, dancqu and others, for whom I have nothing but the highest regard and respect. Gentlemen, the last thing I would want to do is alienate any of you (if I may be so bold as to address you directly). My doctorate is not in photochemistry or engineering and, although I can understand much and at a rather high level, I have not devoted a lifetime or career to studying the literature and doing lab work in those disciplines. I don't have the literature in my library, have not studied it, and do not have the immediate familiarity with the discipline that you do. The reason I turned to this forum for answers in the first place was to learn from your years of study and experience. I sincerely hope that my participation and interaction here is understood in that spirit. It was never my intention to stir up a hornet's nest...

Finally, I'd like to say that I have learned much from this thread. I feel more confident with my regime of clip tests and residual silver tests than before. I also know a lot more about the nature of, and problems associated with, fixation. If my original question about the discrepancy in capacity numbers between Kodak publications and Haist's table in Gudzinowicz never gets addressed, I will still have found this exchange both interesting and profitable. Many thanks for that.

I look forward to many other such profitable exchanges.

Best regards,

Doremus Scudder

Doremus;

You are doing just fine here. Not to worry!

One thing you must remember is that Grant wrote his book in the 60s and the data was based on F5 and the then extant papers which had a LOT more silver content (as silver halide). Today, papers contain as little as 1/2 to 1/3rd of the levels used at the time Grant did his work. Of course, that value varies from company to company. Kodak based their latest figures on F5 (or Kodak Rapid Liquid Fixer - also acid and hardening like F5 but based on Ammonium salts) and using their last runs with papers. I have found that Kodak Polycontrast IV fixes more slowly than Ilford MGIV by about 25% due to its makeup. Therefore, this will affect clearing time.

Now, that said I must add that the same thing goes for film regarding silver levels. However, as Silver comes down in film, it does so by a smaller amount, and at the same time, Iodide level goes up making the film harder to fix. So, that is why I use the leader test. It varies so much for every film.

AND, the leader test only tells you that the fixer can "fix" to clarity, not that these complexes will wash out. That is why a retained silver and a retained hypo test are needed after the wash. Hypo clearing agents and the like have no effect here on the test, but in bad fixer do not necessarily help remove the hypo either. That is why I don't rely on them.

PE

PE, can you explain further what you mean when you say "Hypo clearing agents and the like have no effect here on the test" and what that means as far as fixing/washing goes? I don't think I understand that part of what you said.

Doremus Scudder said:

...It seems rather certain now that Haist's numbers are those he intended...

Click to expand...

I'm glad, we got that out of the way.

Doremus Scudder said:

...Gentlemen, the last thing I would want to do is alienate any of you...

Click to expand...

Not to worry, you haven't. We are all friends here!

Doremus Scudder said:

...I look forward to many other such profitable exchanges.

Click to expand...

Me too!

Shadowtracker said:

PE, can you explain further what you mean when you say "Hypo clearing agents and the like have no effect here on the test" and what that means as far as fixing/washing goes? I don't think I understand that part of what you said.

Click to expand...

None of the hypo clearing or wash aid products interfere with the test for residual silver or hypo.

Also, if the fixer is exhausted or nearly so, the clearing agents and wash aids do not "clear" nor "aid". They fail due to the nature of the complexes that have formed.

PE

Got it. Thank you.