Microdol-x replacement

Paul, Ilford wouldn't have published their Technical Sheet P10 if it didn't work, presumably with their films which were then Pan F, FP3 & HP3, the newer Ilford films are less prone to Dichroic fogging. You do not need to use as much Ammonium Chloride as they suggest but you'd need to experiment with the effective EI and dev times.

Ian

Ian,
I looked at the Technical Sheet P10 info you posted on another thread about Ammonium Chloride. I can see that I have all the ingredients except Borax to mix ID-11, and experiment w/NH4CI. Thanks.

Paul

Ian, the url for that Roger Hicks thread is

http://photo.net/black-and-white-photo-film-processing-forum/00Arzw

and he was completely wrong about my assertions being unsupported. Haist, and three Levenson papers, is adequate support.

But at least he had a point to raise -- and it was a point he actually knows quite a bit about. You have just made inflammatory remarks for, apparently, the sake of being inflammatory. We're still waiting to hear about those 'glaring errors.' Alternatively, an apology would do.

Ian Grant said:

Paul, Ilford wouldn't have published their Technical Sheet P10 if it didn't work, presumably with their films which were then Pan F, FP3 & HP3, the newer Ilford films are less prone to Dichroic fogging. You do not need to use as much Ammonium Chloride as they suggest but you'd need to experiment with the effective EI and dev times.

Ian

Click to expand...

I don't disagree, but as I said in my last post I suggest testing first for speed losses and dichroic fog. And watch out for the odor!

PE

FDC, p. 65, refers to the use of ammonium chloride as one of the chemicals used in the earliest super-fine-grain developers. Its use is well established in the pre-war literature, and it was largely discredited by the mid-40s. (Henn?) It's difficult to see why Ilford would be recommending such an old-fashioned technique in the 1960s when they presumably knew about the use of sodium chloride in Microdol. Ammonium chloride has long been regarded as an inferior chemical to achieve super-fine-grain, but who is to say that it wouldn't or couldn't work well with contemporary films? It's just not an obvious first choice.

On the subject of the 1999 Ilford Perceptol MSDS which lists appx 30g/L of sodium bromide, this is a misprint, since that level of bromide would stop development completely.

Today Kodak has developed the use of superior solvents which do not cause dichroic fog; but unfortunately they are very expensive.

As alluded to earlier, Kodak also developed a series of dichroic fog inhibitors which supress the formation of dichroic fog. They too are expensive and mark the transition (pretty much) from Microdol to Microdol-X.

PE

Alan, thank you very much for preparing the 'formula' for Emofin based on the MSDS.

Starting with your question, does the ppd in Emofin contribute to speed, the conventional answer is no. On p. 68 of FDC, I summarize Crawley to the effect that, where ppd is combined with a more active developing agent (and metol certainly is that), then the more active agent is almost exclusively responsible for development and the ppd's function is only to produce solvency.

Now that is only one explanation, and it may not be the correct one, or if it generally is, may not, for some reason or another, apply to this formula. But let's suppose it does. Then what we have is a metol-based two-bath with a much higher pH than usual (the most famous two-baths in the English speaking world invariably using borax or Kodalk for the second bath).

The 'method' used to gain speed increase is dilution, in this case accomplished by the nature of two-bath development. A similar technique is used today for single-bath developers. For example, when XTOL is used for push processing, Zawadzki and Dickerson found that the best approach was to dilute further and develop longer -- as shown in the original time sheets that accompanied the developer. Time and time again, some sort of compensation mechanism has been shown to be the only valid chemical technique to increase film speed. Crawley has also made similar recommendations, and both authorities suggest that this is particularly the best method when dealing with tabular grain films.

Looking at chapter 7 of FDC on Google I see that practically everything discussed in this thread is covered there, including Dignan's erroneous claim re Microdol.

Dan, when I said the assertion that Dignan's assertion re Microdol was erroneous, I was referring to Dignan, of course, not to you. I must say I also doubt that Dignan had any effect on Kodak's treatment of phenidone in MSDS statements. There are some hints in the literature of toxicity with phenidone, but it seems to depend on oral consumption, so provided you don't drink your developer, you should be OK.

In sum, I think Emofin is a speed-increasing, compensating metol developer, which uses ppd to decrease grain. One interesting thing about the fine grain mechanism in Emofin, in comparison to Microdol, is that the ppd probably decreases grain evenly throughout the tonal scale. It has been established that sodium chloride is proportional in effect, working preferentially on the highest levels of exposure. Since those are the areas where grain may be more visible, there may be some theoretical advantage to this, and it is certainly an elegant mechanism. (If I recall correctly, grain is most visible in the midtones.) But Emofin may easily be a superior developer to Microdol, although it most certainly is more expensive to manufacture and is probably considerably more toxic. It also appears that Emofin increases speed, while Microdol decreases or, diluted, at best, maintains it.

It would be interesting to have, with contemporary materials, comparisons of Emofin versus Microdol, and also Emofin versus the MSDS-derived formula. Working within the parameters of the MSDS, I would suggest:

A: ppd sufate, 10g
sod disulfite 1.5g
metol 5g
Sod sulfite 72g

B: sod carb anhy 30g
sod sulfite 35g

adjusting any amount as necessary to reach the specified target pH values the MSDS provides.

Finally, please don't take any of my explanations as authoritative. I'm only stating the balance of conventional probabilities. Other things may be going on here, and there could be any number of additional unlisted ingredients at 1-2% or less that could be having an important effect. All I want to say is that I see nothing in the Emofin MSDS that seems inconsistent with the claims made for the developer.

Finally (again), I would like to explain how I came to publish the authoritative formula for Microdol, and would like to put a question.

Amongst other things I asked Grant Haist, one was, what is special about Microdol and how does it work? He replied, to my astonishment, that the formula was given in his book. At that point, I knew the book almost by heart, and didn't have a clue where the formula was. After a week of further searching, Grant took pity on me and pointed me to the formula that was sourced to Edgar Hyman.

So the question is, who is, or was, Edgar Hyman, and how on earth did he get hold of one of Kodak's most closely held secrets? One which was all the more precious in that it was so simple and could not be patented? I have only been able to track down one other article by him. I begin to wonder if his name wasn't a pseudonym? Certainly, there was a lot of pseudonomy in the photo magazines of the day. For example, Ziff's 'Camera Arts' had several writers never heard of before or since. They were all Bob Schwalberg. Ziff created Camera Arts around 1980 for the sole purpose of getting its rival (whose name I have forgotten) to buy it and cease publication. Sure enough, after about a year, the strategy paid off.

While I'm asking questions, can anyone put me in touch with Ed Meyers, formerly Executive Editor of Popular Photography? The email address I have for him no longer works.

Photo Engineer said:

I don't disagree, but as I said in my last post I suggest testing first for speed losses and dichroic fog. And watch out for the odor!

PE

Click to expand...

Thanks PE, for the warning, I'll pick up a couple of ammonia filter cartridges for my respirator mask.

Paul

Also as a general rule with any physical development (fine grain/super fine grain) process, the larger the grain, the greater the likelihood of dichroic fog. But that is just a general rule. As a general observation, the super fine grain developers that have survived are those based on ppd or a derivative. Those based on solvents such as thiocyanate or ammonium chloride seem hardly to be used at all. In more than a decade of answering tons of emails from readers, there have been a few questions about ppd-based super fine grain developers, and none based on the 1930s-style solvents. Thus it would be very interesting to hear how you get on!

billtroop said:

Finally (again), I would like to explain how I came to publish the authoritative formula for Microdol, and would like to put a question.
Amongst other things I asked Grant Haist, one was, what is special about Microdol and how does it work? He replied, to my astonishment, that the formula was given in his book. At that point, I knew the book almost by heart, and didn't have a clue where the formula was. After a week of further searching, Grant took pity on me and pointed me to the formula that was sourced to Edgar Hyman.

So the question is, who is, or was, Edgar Hyman, and how on earth did he get hold of one of Kodak's most closely held secrets? One which was all the more precious in that it was so simple and could not be patented?

Click to expand...

I also have a question. I have the books by Grant Haist and the FDC and I have read the formula for Edgar Hyman`s Microdol substitute. However, I haven`t yet seen a formula for the replenisher and I know that Kodak did have a replenisher for Microdol-X, so I am assuming that there was also a replenisher for Microdol too. Does anyone know what the replenisher formula is?

I'm new at this so I'll only be looking at grain structure through a microscope to see what's going on. I think I understand the principle of dissolving the edges of the grain crystals. I'll probably have questions later.

Well, there is also the matter of how the silver metal is deposited. Is it tabular, filamentary or what? There is a discussion of this in Mees and James and also in Haist. It influences percieved grain quite a bit as well as sharpness. For example, PPD developers, MQ developers and Solvent developers give different mixes of silver metal in the image area. Looking through a microscope can be misleading as the eye integrates the grain and sharpness.

PE

PE, I understand what you're saying about perceived grain/sharpness. Enlarging sections of the negatives should tell the real story. I'll use the "scientific method", keeping variables at a minimum and look for repeatability.

billtroop said:

FDC, p. 65, refers to the use of ammonium chloride as one of the chemicals used in the earliest super-fine-grain developers. Its use is well established in the pre-war literature, and it was largely discredited by the mid-40s. (Henn?) It's difficult to see why Ilford would be recommending such an old-fashioned technique in the 1960s when they presumably knew about the use of sodium chloride in Microdol. Ammonium chloride has long been regarded as an inferior chemical to achieve super-fine-grain, but who is to say that it wouldn't or couldn't work well with contemporary films? It's just not an obvious first choice.

Click to expand...

P10 was quite a simple Ilford technical sheet discussing Fine Grain developers in general, the company's Extra Fine Grain Developer at the point (1965) was ID-48 which predates Microdol being released at some point during WWII, the previous Ilford EFG developer was ID-44 a Metol/P-aminophenol hydrochloride developer.

The formula for Ilford ID-48 has never been published but it's unlikely to have included Thiocyanate like DK-20 as it remained in production until the release of Perceptol in 1969/70. P10 states that ID-11 & ID-2 can be modified to work in a similar way to ID-48 with the addition of Ammonium Chloride. This may be an indication that ID-48 included Chloride in some form. Kendall had been working in the US for Dupont, prior to his return to the UK as head of Research at Ilford, and would have been aware of the use of chlorides in Fine grain developers in the 30's.

Ammonium Chloride is still used in some commercial film developers and I've never seen anything to suggest it has disadvantages compared to Sodium Chloride, but of course one might be better than the other depending on the formula. This may be the reason why Henn? discredits it, perhaps it wasn't suitable for the substitutes for DK-20 he was working on.

European & independent US manufacturers formulae often took different approaches to Kodak, so avenues that were left behind by Rochester and Harrow were explored and sometimes exploited by other companies. So this is why I would disagree witth Bill Troop about Ammonium Chloride.

Ian

The high vapor pressure of Ammonia gas leads to a very strong odor over such developers. Also, the Ammonium Hydroxide present supplies some degree of pH adjustment. If Ammonia gas escapes, then the developer will change both in pH and buffer capacity leading to a rather unstable developer with respect to activity. I suspect that Henn, in his search for an improved chemical for Microdol X would have investigated that aspect. One of the drives at EK was low toxicity and high stability. Ammonia afforded neither.

Another aspect is the fact that Ammonium ion and Chloride ion are both silver halide solvents. In Sodium Chloride, we have only one solvent. So, as Ammonia gas escapes, the activity as a solvent will change. With Sodium Chloride one has the best of all possible worlds.

That would be what I was thinking if I were in Dick Henn's shoes. Having talked to him quite a bit, I can say that he used to reason that way. But, we never talked about Microdol X, we talked about monobaths and Grants Latest work. Often Grant was there as well. So, I can't say I have direct knowledge of his reasons, but I suspect what I have said here is close to the mark.

PE

Ron, I too never discussed Microdol with Henn. We talked mostly about his approach to acutance, other developers, painting, his beard, in short, everything but Microdol. I agree with your reconstruction of his thinking; he was the most practical of men.

I would only reiterate that another reason to prefer sodium chloride is the proportional effect, which was only described in the 1970s in the literature but which is obvious from visual inspection of the characteristic negatives where only the high density areas are brown (i.e. where physical development has taken place).

Ian, I would be surprised to learn of contemporary commercial developers for pictorial film that employ ammonium chloride. Could you name some of the ones you refer to?

Keith, if you had been present at the lawn sale following Dick Henn's death, you'd have been able to get the formula for Microdol replenisher 'on the open market' ! It shouldn't be too hard to guess . . . .

I came across this remarkable paragraph in FDC3, p. 46 - - can anyone spot what is wrong? There will be a prize.

'When exposed silver halides are reduced to metallic silver via the development process, there is always a degree of extraneous, unexposed silver halide that remains attached. Fine grain and superfine grain developers make use of solvents to dissolve as much of the extraneous silver as possible. The more efficient the solvent action of the developer, the finer the grain.'

Now that is interesting! Bill, when I knew Dick, at EK, he never had a beard. He was clean shaven and rather a tiny person, very thin and appeared dwarfed by his desk when he sat behind it.

But yes, his notes went on sale in the yard sale after he died. I know who got them!

No, it was not me.

PE

Photo Engineer said:

...Another aspect is the fact that Ammonium ion and Chloride ion are both silver halide solvents. In Sodium Chloride, we have only one solvent. So, as Ammonia gas escapes, the activity as a solvent will change. With Sodium Chloride one has the best of all possible worlds.


PE

Click to expand...

Isn't two solvent action more efficient if used as a single shot developer?

Would the activity change over 10 min. ?

billtroop said:

I came across this remarkable paragraph in FDC3, p. 46 - - can anyone spot what is wrong? There will be a prize.

'When exposed silver halides are reduced to metallic silver via the development process, there is always a degree of extraneous, unexposed silver halide that remains attached. Fine grain and superfine grain developers make use of solvents to dissolve as much of the extraneous silver as possible.

Click to expand...

Well, I just woke up so I might be a bit fuzzy, but
I am not sure the silver halide remains so much "attached" as simply "remains"...

and the "solvents" are generally thought of as silver halide solvents, not silver metal solvents...

Good morning?

Dick's notes went on sale in the yard sale after he died.

Click to expand...

Bill has mentioned this before.
So, which formulas does Henn's collection contain?

If it contains Microdol... then why the impliclate Haist as the bean spiller?
Since it is doubtful the book will ever be freely and openly shared,
could someone just tease us with it's table of contents?

Good fortune evolves...

panastasia said:

Isn't two solvent action more efficient if used as a single shot developer?

Would the activity change over 10 min. ?

Click to expand...

I really don't know.

The use of NH4Br in general practice was abandoned in the 40s or earlier. I suggest you look at some of the older texts on developers. I suspect that in single use developers it was no problem. I would add the Ammonium Chloride at the last step before use.

PE

Ray Rogers said:

Bill has mentioned this before.
So, which formulas does Henn's collection contain?

If it contains Microdol... then why the impliclate Haist as the bean spiller?
Since it is doubtful the book will ever be freely and openly shared,
could someone just tease us with it's table of contents?

Good fortune evolves...

Click to expand...

The notes and "black book" presumably contained everything.

PE

billtroop said:

The more efficient the solvent action of the developer, the finer the grain.'

Click to expand...

Well, if we are talking about silver halide solvents... then a rapid and infinitly soluble AgX would be terrible... putting aside the possbility of physical development for the moment, you would lose the image!

Of course, we would normally assume the above statement to be valid only for the "normal" range found in commercially successful developers, and not interpret it at it's raw face value.

Ray Rogers said:

Well, if we are talking about silver halide solvents... then a rapid and infinitly soluble AgX would be terrible... putting aside the possbility of physical development for the moment, you would lose the image!

Of course, we would normally assume the above statement to be valid only for the "normal" range found in commercially successful developers, and not interpret it at it's raw face value.

Click to expand...

No, you do not lose the image. The latent image is still there as silver metal and can be revealed by the proper process. This is outlined in the patents on catalytic imaging in which the silver halide is totally removed leaving only the latent image. That silver is then amplified to give a normal speed/contrast H&D curve.

PE