washing negatives - Does the fixer leach out?

[billtroop]

"In my own testing, when I take a reel of film out of my fixer (either Neutral Rapid fix or Clearfix), rinse it in water for 10 seconds and then immerse it in a big bucket of water and vigorously shake it for 1 minute, the residual thiosulfate level is already ridiculously low and below the archival standard for camera negative emulsions today. Doing the same in a small tank will require a change of water a couple of times. That's exactly the point of Ilford system. Total washing time of less than 2 minutes can meet or exceed today's archival standard for residual thiosulfate, if the fixing and washing procedures are correctly performed."

Ryuji is confused. Let me clarify. If you fix film in reasonably fresh alkaline fixer, archival levels of washing will be reached very quickly, even before hydroquinone is released from the film. But this mechanism does not occur with the Ilford system, which is based on acid fixing.

It also points up the fact that hypo is not the only thing that needs to be washed out of the film. So does residual hydroquinone and other chemicals. These must be tested for before any general recommendation can be made.

This discussion has made it clearer than ever to me that the Ilford recommendations are unsafe. I am reasonably convinced that they derive from a misreading of Levenson's paper. I don't think this recommendation derives from any scientific work that Ilford did. I would guess that it is merely some documentation technician's sloppy work. It does not warrant such extensive discussion.

It is alarming to me, Ryuji, that in the paragraph quoted above, you would attempt to extrapolate findings based on alkaline fixing to a system based on acid fixing. In addition, what other residua have you tested for? Some hard data and methodology would be welcome, and you must take care in future not to make general recommendations on washing based on your experience with alkaline fixing when you are addressing a general audience, since most of the world does use acid fixing, and washing recommendations must be made in accordance.

There will always be a substantial savings of film washing time when alkaline fixing is employed. But, as has been known for several decades, when alkaline fixing is used, archival levels for thiosulfate are reached long before HQ (or other chemicals) have been released to safe levels. You must therefore test for this and account for this in your recommendations, which you have failed to do.

 

[dancqu]

After the first wash, as we agree, it's a simple diffusion
process depending on the diffusion gradient, but I'd dispute
your assertion that 'pure water diffuses in' which is a bit like
saying 'letting the cold in' rather than 'letting the heat out'.

Yes, water taken up by the gelatine, but this is nothing
to do with the diffusion required for washing, which is
getting the fixer (and fixer products) out.

By the upper portion of that paragraph a vacuum would
form in the emulsion. The lower portion of the above
quoted paragraph makes no sense.

In reality wash water rushes into the emulsion at a rate
dependent upon the concentration gradient and the nature
of the solute within the emulsion. Although the emulsion is
not a classic example of a semi-permeable membrane it
does share some of it's characteristics.

So, an osmotic pressure builds. Reticulation may be induced
and can be intentionally induced. Introduction of the emulsion,
prior to washing, to a warmed solution of high ionic strength
can force an intentional reticulation. Dan

 

[Photo Engineer]

Dan, Roger;

I posted this before but I'll try another viewpoint.

Imagine a piece of wet film, saturated by fixer. Immersion in film may cause any one of 3 things, assuming no agitation.

1: No change in swell - in this case, fixer chemistry diffuses outward to the surface, and builds up slowing further diffusion of fixer out of the film and thus slows washing. No fresh water per-se enters.

2: Swell - in this case a fixer chemistry flows outward and water flows inward diluting the fixer remaining in the film. Fixer builds up on the surface of the film. This is why alkaline fixers help wash. There are chemical means to accomplish this as well.

3. Reduction in swell - Fixer and water are forced outward and away from the film in a plume until swell is stabilized and then a skin of fixer chemicals builds up on the surface of the film. Further diffusion outward is slowed due to the smaller openings in the gelatin matrix. This is what happens in acid or acid hardening fixes. It requires longer wash times.

In all cases, agitation removes the excess fixing chemistry that accumulates on the surface and is useful, as are changes in water by any means. Outward diffusion in all cases is a more or less precise measure based on path length, size of interstices and concentration.

Osmotic pressure builds in semi-permeable membranes but not in gelatin films because they are, by their very nature, completely permeable to water and chemistry. Reticulation is caused by denaturing of the protein and can be caused by chemicals as well as heat. A mixture of both can also do it.

So, some chemicals can cause instant reticulation.

Denaturing is the process by which the strands of a gelatin matrix take on an unnatural coil with respect to other strands and since they no longer occupy nested positions they form domains which are the typical pattern we associate with reticulation.

This is an overly simplified description of a very complex process. I have studied it for years without knowing everything about it yet.

PE

 

[billtroop]

>Yes, water taken up by the gelatine, but this is nothing
to do with the diffusion required for washing, which is
getting the fixer (and fixer products) out.

Dan, don't forget that you may still have developer products to get out. You will have had to rinse pretty well before fixing to get all of the developer products out.

In any case, consider the amount of water used by the fine art black and white photographer or hobbyist, a vanishing race. What is that compared to what it was thirty or forty years ago? Quite insignificant. The b/w photographers who are left are those who are interested in preserving their work as long as possible. Hence, it does not make sense to stint either on water or on time. Better safe.

 

[Roger Hicks]

By the upper portion of that paragraph a vacuum would
form in the emulsion. The lower portion of the above
quoted paragraph makes no sense.

In reality wash water rushes into the emulsion at a rate
dependent upon the concentration gradient and the nature
of the solute within the emulsion. Although the emulsion is
not a classic example of a semi-permeable membrane it
does share some of it's characteristics.

So, an osmotic pressure builds. Reticulation may be induced
and can be intentionally induced. Introduction of the emulsion,
prior to washing, to a warmed solution of high ionic strength
can force an intentional reticulation. Dan

Fair comment. Wooly thinking on my part. Probably posted after dinner. Same response to PE's most recent post, which made more sense to me.

But I can't help feeling that this is turning into a pissing contest. It comes down to this:

Everyone who has ever tested the Ilford method, using a non-hardening fixer, has found that it works.

One paper, apparently accommodating hardening fixers (specifically excluded from the Ilford procedure), advocates more washing. Surprise.

I don't really mind being wrong, and I've learned a great deal from this thread. And as PE says, each of us can decide what to do for his own film. All that worries me is the 'fear factor' which always leads to more effort, time and expense in doing something unnecessary, on the specious grounds that if it's more difficult, expensive and time consuming it must also be better -- a not uncommon world-picture, particularly prevalent among some kinds of photographers.

Cheers,

R.

 

[Photo Engineer]

Roger;

I don't want this to be a contest.

Fear factor is what causes people to do more than needed such as using wash aids. Remember, they were unknown years ago and there are many fine prints surviving from those days.

So, use what works and don't go overboard. Use tests on the prints. This helps by indicating the state of fixation and wash. You don't have to use wash aids for good results.

PE

 

[dancqu]

One paper, apparently accommodating hardening fixers
(specifically excluded from the Ilford procedure), advocates
more washing. Surprise. Cheers, R.

IIRC that is an Ilford warm tone paper for which they
recommend a longer wash time; for the warmth. Wash
more for more warmth? How Now ... ? Dan

 

[Photo Engineer]

Dan;

As I have said over and over, the emulsion type, support and thickness all govern wash times. The articles cited by Bill Troop tell the whole story, but the Ilford data only tells part of it.

This is a matter of safety factor.

Use what you want and what 'seems' to work.

PE

 

[Michel Hardy-Vallée]

Later this week, I'm going to test for residual hypo in some negatives I have washed with the Ilford wash method. I have the Photographer's Formulary residual hypo test, which I think is a mixture of silver nitrate like the HT formulae of Kodak.

I suppose this should tell me if in my own particular case, the wash was successful or not? Or are there other chemicals to worry about?

 

[Roger Hicks]

Roger;

I don't want this to be a contest.

Fear factor is what causes people to do more than needed such as using wash aids. Remember, they were unknown years ago and there are many fine prints surviving from those days.

So, use what works and don't go overboard. Use tests on the prints. This helps by indicating the state of fixation and wash. You don't have to use wash aids for good results.

PE

Dear PE,

Sorry, I didn't mean you. You are, after all, the one who said 'They're your pictures'. It's really film washing that I'm talking about: wash aids and a waste of water. People always tend to 'gold plate' things, adding their own (frequently enormous) safety factors to things that already have big safety factors built in. I'm just warning against that.

Cheers,

R.

 

[Ryuji]

All that worries me is the 'fear factor' which always leads to more effort, time and expense in doing something unnecessary, on the specious grounds that if it's more difficult, expensive and time consuming it must also be better -- a not uncommon world-picture, particularly prevalent among some kinds of photographers.

Completely agreed.

Another thing is that people who read stuff like this on APUG are ill-advised when people keep going on the pissing contest, like you said. People say all sorts of things that are better unsaid for the purpose of keeping the novice safe from pure speculations and poorly tested methods. (Actually, many such things are printed on popular darkroom books as well, tho this shouldn't be a surprise.)

Generally speaking, for the film and RC prints, people should be worrying about keeping fresh fixer and ensuring to give fixing time that is at least twice as long as the clearing time, rather than strange theories that are incorrect, irrelevant and actually non-issue. The ISO standard for maximum silver content is 5 to 8g/L of silver in a liter of standard-strength fixer solution. Some manufacturers give unrealistically high fixer processing capacity if the user is to keep on the safer side. If the silver level is beyond this level, use of washing aid is strongly recommended. Another approach is to use two stage fixation. Fiber prints have to worry about wash time in addition to these factors.

In short, users are advised to ignore poorly tested offhand opinions from places like this thread, but rather follow instructions from manufacturers that test their products and instructions very thoroughly.

 

[Roger Hicks]

In short, users are advised to ignore poorly tested offhand opinions from places like this thread, but rather follow instructions from manufacturers that test their products and instructions very thoroughly.

Dear Ryuji,

Precisely.

To quote Mike Gristwood, late of Ilford,

"Why do they think we'd give them the wrong information? Spite? After all, we really WANT to stop people getting the best results with our materials, don't we?"

Cheers,

R.

 

[dancqu]

As I have said over and over, the emulsion type,
support and thickness all govern wash times.

This is a matter of safety factor.
PE

Well it is apparent that a print's hue also governs
wash time. With regard to the paper in question it
is NOT " ... a matter of safety factor." According to
the Ilford PDF the extended wash is needed to fully
bring forth the warmth of a specific paper. Dan

 

[Philippe-Georges]

Now, when the main protagonists have performed (this is why it is called a forum), they can come to a conclusion, of the same tenor if possible.
They might tell us, mere mortals, once and for all, what the really best way is to wash film AND paper, economically, efficiency and inveronemetally.
By this, who knows, further questions, doubts, discussions and, perhaps, accidents can be avoided.

With all due respect, Ryuji, P. Gainer, P E, Bill Troop, dancqu, Michael and others, what is your verdict?

And why should this final (and absolute) answer not be given a special place on this forum?

Philippe

 

[Michel Hardy-Vallée]

With all due respect, Ryuji, P. Gainer, P E, Bill Troop, dancqu, Michael and others, what is your verdict?

And why should this final (and absolute) answer not be given a special place on this forum?

Philippe

Not sure if I am the Michael quoted, as my name is Michel, but just because I like to talk, I will only say this:
(there was a url link here which no longer exists)

That gives at least 1152 possible cases (I calculate only 4 types of toners).

Many of these cases are similar and functionally equivalent, but my definitive answer would be: the more you do things like using a hardening agent, exhausted fixer, single-bath fixation, tone in selenium, use FB paper, and the softer your water, the more you will have to wash and require a wash aid.

Once these general guidelines are followed, a testing procedure should help you validate your approach.

 

[Photo Engineer]

Well it is apparent that a print's hue also governs
wash time. With regard to the paper in question it
is NOT " ... a matter of safety factor." According to
the Ilford PDF the extended wash is needed to fully
bring forth the warmth of a specific paper. Dan

Dan;

I might ask you what is changing that hue?

The fact that it does change indicates that something is changing in the paper as a function of wash time. In situations like this, it is a case of something washing out of the paper that does not wash out properly without extended time due to thickness of gelatin, hardness or amount of silver halide salts retained.

Therefore, this gets me back to the same statement that I made previously, and that is, you have to have a safety factor. You often don't know if what you are using is good enough for a year or more or sometimes 20 or 50 years. That is the problem.

I would like to point out that I'm probably the only person here who has a fixing material on the market (Kodak RA blix - originally EP3 blix), and who has patents on fixes, blixes and stabilzers. I have also run thousands of image stability tests and I can say that adequate safety factors are a must and you can be blindsided.

Be careful out there. Not all water supplies are the same, nor are all fixers or papers or films. Test your final prints and negatives. Remember that the color tests are far less sensitive on film if you look through the film. You must lay them down on white paper for viewing the test spots. Fixing time and wash time can climb rapidly with exhaustion of the fix. This varies with the fix and the material being fixed.

PE

 

[billtroop]

>Precisely.

To quote Mike Gristwood, late of Ilford,

"Why do they think we'd give them the wrong information? Spite? After all, we really WANT to stop people getting the best results with our materials, don't we?"<

Roger, use your head. When there was a water crisis in Britain sometime in the 70s, Kodak Harrow, under Levenson, did a lot of research to discover how to wash film economically. Their recommendation was five-minute waits between several water changes. Materials have not changed dramatically enough since those days to invalidate this research.

Had an Ilford scientist discovered that the Kodak work was completely invalid, so much so that the five-minute waiting time could be reduced to nothing, which is a matter of several orders of magnitude, don't you think they would have published some scientific data on this major discovery?

They haven't. It is not a discovery. There is no discovery. It is a simple document technician's mistake, which of course the company probably must now stick by, as it would be too embarrassing to admit it after all this time.

Ryuji has become fatally confused, applying rough data gleaned from alkaline and neutral fixing to the Ilford system, which is based on acid fixation. His opinions also are unsupported by a shred of either published data or even the presumption of any professional experience.

The only person on this thread who has the slightest hands-on experience actually working for a respected major manufacturer, in a respected major research position, in fixing technology, is Ron Mowrey. Who is more likely to know what is what? The strangely degree-less grad student who's an amateur photographer, or the actual Kodak scientist with several decades of patented work under his belt?

I realize you're one of those persons who can't bear to be in the wrong, and I sympathize with that because I am just the same, but I think you're taking this to extremes, with a campaign extending over at least two years on just this one point. Let me tell you what is the most frequent sentence I have heard Grant Haist utter in the two decades I've known him: 'I don't know.' I think I learned more about science from those three short words than from anything else. About science, and how to approach science.

Roger, I realize you are a forceful person who likes to make his opinion felt, but before encouraging less sophisticated users to use a washing technique that has no scientific basis whatsoever, you should ask yourself if you are really prepared to accept responsibility should valuable negatives be ruined because of your advice?

And by the way, Roger, I'm still waiting for you to fill me in, publicly or privately, on the "unsupported assertions that are not widely accepted by other authorities; many opinions masquerading as statements of fact: and some flat errors" that you have stated my book is filled with

Well, Roger? Are you up to it? This is your chance!

 

[Roger Hicks]

Well, Roger? Are you up to it?

Not really. As you say, neither of us likes being wrong. If you want to be the one who thinks he's won, I'll concede. Life isn't long enough to conduct the kind of dispute that would be involved, especially when I am dealing with someone who tells me to 'use my head'.

I do not wish to imply in that reply that I think I've won either. Or lost. I am happy to admit that like Grant Haist, 'I don't know' (in fact, fairly obviously, I know a good deal less than he does). I am not, however, convinced that I am alone in this, e.g. Film Developing Cookbook, page 15, your opinion that the only reason for the existence of tabular grain films is to maximize profits for Kodak and Ilford; page 34, your opinion that plastic reels are almost always more convenient than metal; page 66, your approving quote of Schwalberg against using 3 dev agents, when you also quote Geoffrey regularly with approval (he advocates 3 to straighten curves). I can't be bothered to go through the whole book again -- I've not looked at it for a while, and had to find it to answer this post -- but as I say, I'm not interested in a protracted pissing contest. Your book is very good, but it's not Holy Writ, and it's not infallible. Nor are my books, and I don't pretend they are; but when they read my books, people expect opinions, which I try not to mask as facts.

Oh: and as for 'valuable negatives being ruined because of my advice', obviously I wouldn't give that advice if I thought there were the slightest risk of ruining any negatives, valuable or otherwise, from following Ilford's washing advice with non-hardening fixers. No-one I know of, who has tested the Ilford approach with non-hardening fixers, has found anything other than what Ilford claims: ANSI archival washing. Have you tested it?

Cheers,

R.

 

[Ryuji]

Roger,

I certainly agree with your opinions here and can make the list longer. Some are opinions with no right answer, but many others are clearly errorneous statements. I have many references, much experience and own test results to back them up. However, I think you would be much happier if you abandon the provocative internet forum professionals and stop dissipating your energy in competition with them.

 

[billtroop]

Roger, just for the record, a lot of what is in FDC is, I suppose my opinion, but it all comes from somewhere; none of it comes out of thin air. I am not a researcher, but I know a lot of researchers and I am a good synthesizer of information The opinion about T-grain derives from Haist, who knew that for most of the T-grain emulsions, less silver would have to be used. That was a huge concern for Kodak, especially following the Hunt's speculations in the 1970s. Haist's opinion is doubly worth listening to on such a matter because he was the only photographic scientist of his calibre who was also a successful commercial photographer (in his spare time of course). I understand that some T-grain emulsions have wound up using more silver, but I understood that predominantly there was some savings. What the situation is now, I have no idea. Plastic vs metal is Steve's and my consensus -- we realized we were going out on the line there, but it was what we both strongly felt. Obviously people who are really good with metal reels prefer them. But to people who want advice, ie, they're relatively new to photo processing, I still think plastic is the simplest bet.

The Schwalberg/Crawley thing is interesting, isn't it? What Schwalberg really meant was that someone like Champlain (sp?) was nuts. I don't think he knew that Crawley used three agents in his commercial developers. Crawley has, as far as I know, only used three agents in formulas with phenidone -- I think that would be the only case where he might recommend it. None of his recent published formulas contain three agents, and it would be interesting to know how his thinking has evolved on this point. I will ask him the next opportunity I get. I think Acutol contains only phenidone and hydroquinone. I was very surprised to learn that. I didn't think it possible to get that degree of sharpness in a PQ developer.

Finally, no, I haven't tested Ilford's claims. I am perfectly aware that neither I nor anyone else outside a Kodak-quality laboratory can possibly make this test in a way that I would consider adequate. Of all the people with home labs, Ryuji is one of the few I would take even half seriously, but as he never posts anything even approximately scientific in quality, but just utters opinions, I don't take that seriously, especially as regards a serious matter such as this. What is terribly significant is that he has stated that his testing of the Ilford method has only been conducted with alkaline or neutral fixers. That being the case, washing out of hypo residue will be exceptionally rapid. But the same results will not occur with acid fixing -- that I know. And the Ilford method is intended for people who are doing acid processing.

Roger, what's interesting to me in all of this is the degree of difference between Kodak and Ilford here. With Kodak, it's five minutes between five or six washes, with Ilford it's zero minutes. This is not a small or subtle or incremental amount. This is huge. There has to be something the matter here. Either Kodak is flat out wrong, or Ilford is flat out wrong.

The thing about Kodak testing is that it would involve thousands of different materials, different water qualities, and different processing conditions, and the constant expectation that processing before washing will not necessarily be optimal. I doubt that Ilford even in its heyday could practically have budgeted the resources to conduct this kind of study in Kodak-quality depth. It's not that I want to sound like a Kodak apologist, but I have an ineradicable respect for what those research labs were capable of before the mid-1980s and even for some years after that.

I realize my attitude is a little conservative, but I prefer to think it is so in the best sense. Until there is some scientifically credible information that contradicts Levenson -- and there is none -- Levenson is the gold standard. I would mess around with developers, experiment in all kinds of ways. When I was formulating a new developer every day, I entrusted negatives to them I wouldn't have wanted to lose. And I was lucky, I never actually lost one. But I was sufficiently vain to be concerned that my negs would last for decades. In fact, I thought I was a much better photographer than I probably ever was. Oh gosh -- notice that hopeful 'probably'? Still can't let go.

Finally, in a book without extensive footnotes, I cited what I thought was most important to cite. But I put in a lot of things that it wouldn't have been seemly to quote directly from their originators. Yet I wanted to get what I had learnt out there. There is not much I would retract ten years later, though I am hopeful an improved 2nd edition will come out if anyone is interested in publishing it at this late date.

For one thing, we should have said more about metal reels. . . . . the book I originally wrote was about five times longer (no exaggeration) and would have been unpublishable in the late 90s. My question is, what is publishable today?

 

[Roger Hicks]

Dear Bill,

Thanks for your very reasonable reply. There are so many things here that are a matter of opinion, and even Haist isn't infallible: I've heard him argue that ONE developing agent is all you need (in conversation, when I visited him to buy the book), and while there is probably no-one alive who knows more than he, not many would agree with him on that one. I specifically discussed this with Geoffrey a few weeks ago, hence my comment on line-straightening; he still believes in this.

All I can say about the washing is to repeat that everyone I know who has tested the Ilford wash sequence, with non-hardening fixer as recommended, has confirmed Ilford's findings. I am happy to believe the results of my own tests, the more so when they are confirmed by so many others. This suggests to me that Ilford's suggestions cannot be flat wrong. Ron suggested that the 5-minute wait was to accommodate hardening fixers, and this seems entirely believable to me.

And I fully take your point about a book five times the length, and deciding what to omit.

Cheers,

R.

 

[Photo Engineer]

You know, when I was editing or proofreading Grant's book, I would often ask him about a given statement and he would say "Dick told me" or "Bill told me" or "Joe told me" or "Keith told me". Well, these were Dick Henn, Bill Lee, Joe Altman or Keith Stephen. (go ahead, you look them up, I know all about them so I don't have to)

So, I would ask them and they would show me the data or the reports. The thing is though that when these names were mentioned, truthfully I didn't bother in many cases as I knew their reputations either within Kodak or outside. I worked closely with Keith on Blixes, Bleaches and Fixes myself, so that data was very close to me and I routinely read all of his internal reports. In fact, some of the comments in the book come from me as well as those others (Blushes are in order, but it is a fact. See the comments by Grant in the book.)

The thing is, they were respected associates who's work I would not question and Grant was often quoting conversations with them just as Bill often quotes conversations with Grant.

I asked Grant why he asked me to edit it. He said "You know these people and their work. Some of it is yours anyhow, so it should make your job easy". That is an approximation of what he said.

In any event G. I. P. Levinson is also a respected Kodak worker who's work I have read from time to time as well as that of hundreds of others. I have discussed some of these posts with fellow Kodak retirees and current engineers. They express total disinterest in posting here, but agree that Grant is an acknowldged authority! In my mind, Bill is inheritor of much of that information.

I have tried asking Grant about a lot of this stuff, but his comments are "I knew that at one time, but I forget now". Time and knowledge pass. Lets try to get the right stuff documented and avoid the chaff.

If someone who is not an expert posts something, they should accompany it with data or references. If I tell you I make an Azo like emulsion, I post pictures and send out samples for review. Bill has a book that is well accepted. I think that is the kind of 'proof' that is useful to us here.

BTW. I have heard Grant say that the use of 3 developing agents is useless or foolish. I have also heard him say he prefers one, and he has designed some fine developers with just one. So have I. One of mine was sold commercially for years. I prefer 2 though, in B&W developers and from general evidence I think Grant actually does too.

PE

 

[dancqu]

Have you tested ...? Cheers, R.

Well Now! An opportunity for Mr. Troop to toot HIS
own horn for a change. Perhaps a list of Journals of
this and that Society in which his findings have been
published.

For myself I tire of the endless applauding and leaning
upon of such as Levinson and Haist who finished their
work 40 and even 50 years ago. Dan

 

[Ryuji]

For myself I tire of the endless applauding and leaning
upon of such as Levinson and Haist who finished their
work 40 and even 50 years ago. Dan

I see Gerald Levenson's name misspelled frequently in this thread. His name is Levenson not Levinson.

Although most of his important work is from 40s to 70s, Levenson was active even in 1990s. He wrote a few very nice expository articles in early 90s (and generally speaking he is very good at describing things in reviews, encyclopedia, etc.).

Some of the most important discoveries about superadditivity of developing agents were Levenson's work as well. It is pretty silly to argue how many developing agents is best, etc., without specifying what your goal is.

 

[Photo Engineer]

Dan;

Grant's work continued to 1988, and would have continued beyond. He was working on an update to "Modern Photographic Processing" and another entirely new textbook. He was working with members of KRL at that time to keep current in his references.

It was unfortunately interrupted by the untimely death of his wife followed shortly by his severe stroke.

The work of Levinson was continued by Keith Stephen, who died suddenly in the early 90s, and my work was diverted to film design, color reproduction and then emulsion making.

BUT, there were dozens of others doing R&D in this area at Kodak including Dickerson and Zawadski to name two. And, one cannot forget Kapecki who was doing lots of image stability testing and is on the ISO committee.

Bill Troop has recorded the legacy passed on to him by Haist among others. At least he has a book published and knows his chemistry. I have met Bill and talked with him for hours two years ago discussing development, fixing and image stability. I have no qualms about endorsing his work whatsoever.

He has made no claims about having his own original scientific work, as he can cite abundant references continuing up to the present day, as he still does research of the literature. We have seen that in this thread.

So, since his comments are accurate and he knows works being currently done, and can discuss them intelligently with me, Grant and others who have published, then I can accept his word without question. You, OTOH, seem to know little about Grant, his work, or the work currently being done.

Some of the work cited by Bill took place up to shortly before Grant had his stroke which would place the work published in A&T as current as the mid 90s. Bill has material gathered for a new edition since then. He mentions that above.

PE