Grain clumping, a controversial issue

It's fascinating that in study of image structure, the study of graininess, sharpness, acutance, contrast... namings and definitions are not easy, and so, discussion is not easy. Like much in photography, those definitions and names are a can of worms.

Mark Antony said:

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Hmmm ... Mark Antony's image does indeed look quite like a can of worms. Maybe we should refer to such appearance as "worminess" rather than calling it clumping, since "worminess" refers just to an observed appearance, and does not impute a movement or process to create that appearance as "clumping" does. It is useful to try to tease out metrics that are as independent as possible to try to sort out root causes.

If gelatin does not move, then the silver does not move by more than about 2 microns according to the work of Ross. He used either Formalin or Chrome Alum as hardener, probably the latter as it is preferred on glass plates. Since astronomers still use plates to some extent and routinely check star positions, I would say that the work is still valid. I know that a Kodak research worker was assigned to the observatories in AZ for several years during the 70s checking out this type of work.

That said, if gelatin moves, then silver moves with it and relative to the gelatin movement. I have actually caused blisters in films and papers and have been able to lift the emulsion from the support and view the image. BTW, Kodak sold "stripping films" that did exactly this and remained intact for transfer to another support. The stripping was normally carried out at 100F.

All grain is typically reported as RMSG. It is accompanied in many cases by photo micrographs down through the film and with cross sections to show the grain pattern. I have posted examples of both in my OP. It is critical to understanding this that silver takes many forms due to development conditions and grain type and these appear different to the eye and appear different when measured by an instrument.

PE

Photo Engineer said:

That said, if gelatin moves, then silver moves with it and relative to the gelatin movement.
PE

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That's the theory and practice in most cases.

When it goes wrong you used to get full reticulation with most typical films (up until the late 60's), with modern hardening few films have issues, but apart from the relatively unhardened EFKE films which aren't remotely typical there's a small number of films are prone to issues.

Stripping films work in a different way with an unhardened subbing layer and a hardened emulsion.

There's some crossed thoughts in this thread because Ron's original post support the practicalities that with modern (available) film developers it's not temperature or pH themselves that affects grain (& grain clumping).

What's also confuses is the term Grain clumping has been historically used to cover more than one type of large/excessive grain seen in practice.

What is known is that with full blown reticulation there is Silver migration (Mason et al) where little work has been published is the stages prior to full reticulation, but we know it exists.

It reminds me of my Virology lectures at University in the mid 90's when our lecturer (an eminent virologist) told us they knew cervical cancer was often caused by a virus, but they had no proof, that took another 20+ years.

In the case of micro reticulation/grain clumping companies know why it happens so why pour research money into it, they already have a cure . They improve film hardening instead.

However for other reasons, possibly to get better film speed and other characteristics etc both Kodak & Fuji make 400 ISO films that are significantly less well hardened. These are the films that show the most micro reticulation.

Ian

More on grain

I posted an RMSG plot earlier to show the variations introduced by differences in development time.

To back this up further, here are some actual grain pictures taken from Haist (with permission BTW)

From left to right

1. Early stage development
2. Late stage development
3. Using a physical developer
4. Using a straight chemical developer

In like manner, the appearance of the grain varies substantially as a function of pH, time, temperature and Grant goes on to add that it also varies as a function of exposure type such as bright short exposures vs dimmer long exposures.

And, what is missing in this is that there is a 3D or X-Y-Z component to the image so what you see in these 4 photos are 2D representations of a 3D world more clearly shown in the original post in cross sections.

So, back to these micrographs - you cant tell me that your eye would not see a difference in grain. You are basically seeing under and over development and two different developers. And the result is a huge change in the grain structure, but absolutely no movement of silver beyond perhaps, what Ross reported! And, there are no literature references to "micro reticulation" beyond some scattered statements of individuals trying to explain changes in their negatives which can easily be explained by this post. Adding a 3D component takes us back to the example in the OP where we see stacks of these grains, not clumps.

PE

Absolutely nothing in your posts in this thread Ron explains anything about the excessive grain caused by poor temperature control, and yet in other posts you accepted it happens but that it was not something you'd seen yourself.

Micro reticulation (grain clumping) is not a development phenomenon, it happens afterwards at some point in the stop/fix/wash stages, and your posts illustrate that it's not happening during development ( or the rest of the process cycle used in the tests).

The lack of literary references to micro reticulation/grain clumping other than a detailed illustrated article back in the mid 80's and sporadic later references are hardly surprising, the parameters that cause it with the few modern emulsions that are particularly susceptible would have caused full reticulation in films at the time all the research was done into film hardening.

So there's no reason at all for the film companies to have done research into something that happens to one or two films (out of a larger=) processed outside their recommended parameters.

In addition few of us have issues with micro-reticulation because we keep a reasonably tight control over process & wash temperatures. So even with Neopnan 400 which is the film that currently gives people the most problems many of us have no issues at all, and I process it at 26-27°C which would mean the films more susceptible.

So all the posts so far just help confirm excessive grain clumping due to sharp temperature variations it's not grain clumping caused by any form of developer, and the subsequent process cycles used in the tests.

Ian

Those old posts on these terms actually prompted me to do this research due to the lack of concrete data.

When you do research in texts and on the internet for these subjects, you find the following:

1. Original work by reputable scientists with data. (Haist and Ross)
2. Reports by reputable scientists with educated opinion and guesses but no data. (Mason)
3. Reports by reputable photographers with opinions.
4. Reports that refer to #1.
5. Reports that refer to #2.
6. Reports that refer to #3
7. Reports that comment with no references to any of the above.

When I search for Micro Reticulation or Grain Movement or Clumping, I find that most references are made by Ian Grant using those terms. Haist and Mason refer to Reticulation and Ross says that clumping or movement of silver does not take place. Additional references come from photographers who observe something changes the grain if temperature or process changes even slightly. Most of those people either refer to Ian Grant's posts or they coin the terms themselves or use it without attribute to anyone. No proof is offered.

In addition, Mason states that severe reticulation can cause silver movement and actual exposure to air giving reticulated negatives a silvery sheen. No data is shown. Well, I have seen that effect as well and I would attribute it to actual cracking of the gelatin. If that takes place, you can see the silver metal that is exposed so to me it is a matter of opinion. Haist makes no mention of this effect, but does discuss classic reticulation. Neither of them mentions micro reticulation or clumping.

SO......

Here is my opinion. Silver changes morphology with process conditions. But, so does gelatin! The most common form of silver image is filamentary, kind of like a Brillo pad or Stainless Steel Scrubbing Pad. We have all seen these. Imagine that one of these is entrapped in a huge bundle of gelatin fibers which are invisible to us. As the gelatin bundles expand and contract the silver filamets expand and contract and as they do, they can take different forms. See the posts here of fiaments. Imagine them changing shape with temperature changes or pH changes. In fact, if we removed the gelatin completely, these filaments might contract to a tiny bundle almost like a pebble. This mechanism for changes in grain takes no clumping, does not require reticulation and is the simplest explanation that can be given for the observed facts.

THUS.....

Since we have no proof one way, just words that "something happened" and a group of explanations, the best I can do is offer a simple explanation that fits all of the observations of everyone, whether supported by data or not.

I hope you see the logic in my explanation. However, until we can see data, I suggest that you not slavishly believe in grain movement, clumping or micro reticulation. They appear to be straining at explanations that seem to have no factual basis.

BUT....

Change can take place in grain with changes in pH, temperature, time, developer type, process work flow and etc.. Why and what kind is up in the air, but clumping and micro reticulation strain things a bit based on current understanding.

PE

Still over looking the fact that when Haist and Mason did their research and wrote about reticulation films were significantly less well hardened. So the conditions that cause micro reticulation would have actually resulted in full reticulation.

The fact that excessive grain (grain clumping) occurs as a result of just temperature changes rather than pH, choice of developer, developer temperature and time, and after development is in itself indicative of it being an issue with the gelatin or polymer) of the emulsion itself. That's not to say that pH, developer choice and temperature may well increase the risk of it happening.

The "why & what it is" has been called micro-reticulation because something is happening to the internal structure in the gelatin layer, the visual effect is excessive grain, which is also called grain clumping.

Perhaps you place too much importance on the name given and not enough to the fact that it actually occurs.

A better way of looking at micro reticulation is to think in terms of the stresses in a films gelatin layer just prior to the onset of full reticulation where the surface cracks. We know that Neopan 400 will fully reticulate in some circumstances.

I've quoted this 2003 text before but it's

"The temperature of all the solutions, including the wash water. Is critical be- cause of thc danger of reticulation. Reticulation occurs when the film emulsion cracks. The emulsion swells and softens during processing. The warmer the temperature the greater the swelling. If the temperature drops quickly, the surface of the emulsion contracts while below the surface it remains swelled. This causes small cracks to appear ln the surface. The cracks can appear as a pattern throughout the image when a print is made. Occasionally this pattern can make an interesting image; usually it`s a distraction. A mild form of reticulation, known as grain clumping, can also take place. This makes the image appear grainier and coarser than it normally would with proper processing. This is the major reason to constantly control the temperatures of all solutions."

The author is not the only person to hold the same views as I've pointed out in the past.

Ian

Greg, I don't have the films which are most susceptible here in Turkey, and Tmax 400, well any Tmax, is almost impossible to find here, I might be able to find some Neopan 400 but the nearest store's an hour away and I don't go to the the city very often. My water's not cold enough either.

I've seen it at it's worst when someone else used my tanks and chemistry to process 3 rolls of Tmax400, I've written about it before. He used film from my packs of 120 film, my replenished Xtol, stop & fixer. The only bath I'm certain he had at the correct temperature was the developer, I know he used tap water as it came because I spotted it and reprimanded him, it was a cold day and I'd guess the water was below 10° C, the dev was at 20°C, there's no heating where I stored the stop & fix so they'd have been around 15° C) before warming up (based on last weeks processing while I was in the UK).

I can try with some 35mm Tmax 100 but I don't think it suffers like the 400. I've seen the problem of excessive grain many times over the past 30+ years with films other people have processed, where they've used the same film/developer combination as I have and it's not an exposure/development time issue. This is what Bernard Suesse is calling mild reticulation & grain clumping, which others call micro reticulation.

Ian

Ian;

Who is the quote from? You give no source, just a quote. Most of the quotes I have found from the internet are circular, with a group of people (including you) who are quoting each other with no data. I think that Greg Davis has an excellent suggestion. And, I do agree that something is going on.

Also, Haist had access to the new hardeners. So did I, and it was in the same time frame. In fact, I used them in my coatings in the 70s after we all did research in the 60s when we did swell, abrasion, keeping and reticulation tests. We were just not permitted to discuss them at that time. All R&D was complete before the first products containing them went on sale in 1970. So, you make a grave error when you claim otherwise.

It is interesting that you appear to dismiss my explanation entirely. In any event, the effect I describe can occur with any hardener.

PE

I gave the quote reference before, along with others.

I don't dismiss your explanation Ron it's just you surround it with irrelevance then try to dismiss micro reticulation. So first you say it can happen and then that it doesn't.

The two current films that suffer most weren't manufactured when Mason & Haist did their research, and film hardening improved further with some films. Research was into preventing issues at normal working parameters not extremes caused by sloppy temperature control, and the outcome is that nearly all films have good hardening so there's few excessive grain issues.

Ian

Photo Engineer said:

Imagine that one of these is entrapped in a huge bundle of gelatin fibers which are invisible to us. As the gelatin bundles expand and contract the silver filamets expand and contract and as they do, they can take different forms. See the posts here of fiaments. Imagine them changing shape with temperature changes or pH changes. In fact, if we removed the gelatin completely, these filaments might contract to a tiny bundle almost like a pebble. This mechanism for changes in grain takes no clumping, does not require reticulation and is the simplest explanation that can be given for the observed facts.
PE

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The excessive grain formed by the rapid expansion and contraction is what people call Grain Clumping or Micro Reticulation

Photo Engineer said:

Change can take place in grain with changes in pH, temperature, time, developer type, process work flow and etc.. Why and what kind is up in the air, but clumping and micro reticulation strain things a bit based on current understanding.

PE

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Excessive grain has been called Grain clumping as long as I've been processing films, (mid 1960's) and the effects caused by rapid temperature shifts has been termed Micro reticulation for around 25 years.

Put whatever name you wish on this excessive grain it won't prevent it happening. Mason & Levenson call it Increased Graininess

Ian

Ian;

This is what you said about your references last time you were queried directly:
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"Most of my information etc is in storage back in the UK so I can't look up references etc. There were some research papers but most people took little notice because most good pro's & labs etc keep their temperatures fairly tight in any case so would never come across it at all."
=============================== (Ian Grant, 2009)

Can you please give us the source of the quote you gave above?

A modern text such as "Photographic Materials and Processes" published in 2003 (latest ed) found here: ( http://www.amazon.com/Basic-Photographic-Materials-Processes-Second/dp/0240804058 ) does not even mention reticulation! Even though an entire chapter is devoted to quality control as well as other subjects that could relate to this current topic there is nothing about this subject at all. And the book is very good with high power authors!

BTW, if anything, older films would be MORE subject to this effect than modern films!

As for what I describe, it in no way implies reticulation (a gelatin effect) or clumping (a migration effect). Please don't misinterpret what is very simply stated but using your own terms. I am talking about gelatin's normal swell capabilities and the ability of silver to follow it, as shown by Ross in my OP in the cross sections.

PE

Ian Grant said:

I gave the quote reference before, along with others.

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Strange response. As far as I could tell it comes from "Mastering black and white photography: from camera to darkroom" by Bernhard J. Suess.

Google books link

I don't know Bernhard J. Seuss is, but a quick google search on him reveals (from his website):

I graduated with a B.A. in English from Lehigh University.

I have been working professionally in photography since 1978. I am primarily self-taught.

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Now, there is nothing wrong with English majors or being self taught or being Bernhard J. Seuss. But I don't think that's the scientific source that we were looking for. Presumably he got his information from somewhere else. It does not look like he gives any cites for this information.

Tim, what he wrote is what's been found by many Photographers, University lecturers & Professors of photography via student mistakes, and the advice given by many authors - all based on field practice rather than Kodak or nay other companies research.

Practical usage shows up many short comings in apparently well designed & tested products in all fields, regardless of the research.

I'd add the response is similar to Ron's he won't repeated post quotes & references.

Ian

Tim Gray said:

Bernhard J. Suess.

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Too bad he didn't go for his doctorate...

Photo Engineer said:

As for what I describe, it in no way implies reticulation (a gelatin effect) or clumping (a migration effect). Please don't misinterpret what is very simply stated but using your own terms. I am talking about gelatin's normal swell capabilities and the ability of silver to follow it, as shown by Ross in my OP in the cross sections.

PE

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They aren't my terms Ron, it's you who disagree with terms that have been in use for very many years.

We aren't talking about the entirely normal swell capabilities of a gelatin based emulsion, rather the abnormal rapid shrinking or swelling which occurs when temperature differentials are l outside recommended parameters a films designed to tolerate.

Ian

Well, Ian, what is the use. I have given a whole thread full of posts with references and you have ignored the presented evidence. Why keep on? OTOH, you did ignore the quote I gave from one of your own posts earlier. You generally say that the reference is back in the UK. So, I don't keep giving repeated references, and you don't give them in the first place. Right?

No one in the profession has seen this nor reported it in any journal or text book! Those are my findings. Other references are apocryphal or circular, being given by eyeball observation or recursive each referring to the other rather than having original content.

What I have attempted to do here is provide original content, with references from 1921 - 2003 which illustrate the situation. So, show us an example. And remember that older products should show this problem more easily! So, the earlier works should have been more sensitive to this problem than current works!

PE

Photo Engineer said:

Well, Ian, what is the use. I have given a whole thread full of posts with references and you have ignored the presented evidence. Why keep on? OTOH, you did ignore the quote I gave from one of your own posts earlier. You generally say that the reference is back in the UK. So, I don't keep giving repeated references, and you don't give them in the first place. Right?

No one in the profession has seen this nor reported it in any journal or text book! Those are my findings. Other references are apocryphal or circular, being given by eyeball observation or recursive each referring to the other rather than having original content.

What I have attempted to do here is provide original content, with references from 1921 - 2003 which illustrate the situation. So, show us an example. And remember that older products should show this problem more easily! So, the earlier works should have been more sensitive to this problem than current works!

PE

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You forget the detailed article in Darkroom Techniques published in the mid 1980's which showed the effects quite clearly.

You've dismissed the writings of some of the worlds leading B&W Photographers in previous posts.

You've gone against your own acceptance that the issue occurs based on reports of other members of APUG (not including myself).

I've seen extreme grain clumping / micro reticulation first hand, never with my own films though, But I've seen enough films with excessive grain for no apparent reason to know it was once far more common.


I actually accept the evidence you've presented because it mirrors my own experience that excessive grain (grain clumping/micro reticulation) is not directly caused bychoice of developer/temperature/pH/dev time etc.

Where we differ is I go one step further which would be outside the research processing parameters (of your quoted examples) because I'm 100% sure that the excessive grain is caused by temperature changes that are outside the manufacturers recommendations.

Now why are those parameters recommended, simple - there are or may be issues if you transgress them.

Some times things are so obvious they aren't written about in research papers.

Lets state a few fact, most current films Kodak, Ilford & Fuji are so well hardened excessive grain or any type of reticulation is near impossible to achieve through process temperature changes.

But a few films are still susceptible. There's no way a manufacturer is going to admit that in anything published (even a research paper) unless they'd solved the problem.

You've given an explanation before about why Neopan 400 is susceptible, and there's reports of full reticulation and emulsion frilling. Tmax 400 is teh other major film with reported problems (by many people) and is teh one I've seen first hand.

I don't need to give references to something I've seen first hand, and discussed with leading photographers over a period of nearly 25 years. None I've spoken to doubt it happens.

And yes most of my books are still in storage, have been for 3 years now, and it's not easy to access them.

Ian

Yes, I have agreed that reticulation can take place with some films. There is no problem with that. Micro reticulation and grain clumping as terms describing something are another matter. And, having micro reticulation with small changes in process using most modern films is very unlikely. It is much more so with a film from 25 years or 50 years ago.

I can also agree that grain fluctuations can be seen by some people. But none of this shows what caused it nor does it explain what happened in the film. However, to claim that the film manufacturers are aware of this smacks of conspiracy theory. If Kodak, Ilford or Fuji had a problem, they would fix it or perhaps even exploit it against a competitor in advertisements. IDK.

I do know that if there were published articles in Darkroom Techniques or other magazines, they certainly went way under our RADAR at Kodak even though I was negotiating an article with David Jay, the editor at about that time. He probably would have questioned me on this subject just as a matter of course and if I didn't now the answer, I would have asked Grant. So, this sort of "disclosure" is a non-issue to me.

I see no problems and I would hazard to guess that out of the 40,000+ members of APUG, very very few have seen the problem otherwise we would see posts about it all over the place rather than questions about this effect. In fact none of the posts I have seen here describe having personally gotten this problem. If there is one or even more, they are certainly few and far between. There are more posts about the effect or asking about it than verifying its existence.

PE

Interesting debate, but it's time for Coffee, Anyone?

I say do the stop bath with water @ 13ºC.

dehk said:

Interesting debate, but it's time for Coffee, Anyone?

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Grain Clumping in Caffenol? Please NO!!!!

Well, I have found dozens of reputable posts about grain clumping, and they fit well with the Suess reference earlier!

http://www.ragdollcatguide.com/forum/printthread.php?tid=3324

Yes, there is a lot out there about grain clumping if you just set your mind to it! Thanks all........

PE

^^

Photo Engineer said:

Well, I have found dozens of reputable posts about grain clumping, and they fit well with the Suess reference earlier!

http://www.ragdollcatguide.com/forum/printthread.php?tid=3324

Yes, there is a lot out there about grain clumping if you just set your mind to it! Thanks all........

PE

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Don't forget all the research done on grain clumping in sticky rice! LOL!!!!!