Grain clumping, a controversial issue

[Ian Grant]

Micro reticulation

Very specific films such as the T-Max family have been most quoted.

PE

This is in fact the problem, it's not necessarily the whole of the Tmax family. Perhaps just Tmax 400, which is where I've seen problems and also heard others report of having an excessive grain problem that were temperature related.

I know Mark's now away but he should be aware that there were a few discussions here way back around 2004 on this issue, and there have been previous discussions elsewhere all confirming that there is a temperature related increase in graininess And yes I deliberately steered this thread back to this issue because it needs a consensus conclusion.

I'm afraid that all films have a rather less than perfect surface both before and after processing. The article in question wants to laminate one plate to another. To do so with perfection, one would have to smooth out these imperfections by somehow shaving the surface. So, that is one interpretation of this abstract.
PE

My gut feelings after yesterdays brief reading of Kodak documents is they are saying it's what's happened at the "rather less than perfect surface . . . . after processing" that Ron mentions, and that this is in fact the key at two levels.

Firstly - the slight gain in image quality when reasonably tight temperature tolerances are adhered to.

Secondly - the increased sometimes excessive graininess seen with some films with temperature deviations (probably over 5ºC) during poor or unmonitored steps after development.

So far I have 3 pointers that I'm well on the right track

1: Kodak graded Reticulation, from Slight to Severe, to describe the reticulation observed using the new hardeners They also claim to be reducing reticulation not eliminating it.

2: The Stress in the Gelatin surface cause variations in the final position of Silver after drying. (Kodak paper, no verifiable modern references all internal Report or messages).

3: Microscopic surface reticulation is acknowledged to exist.

1 & 3 are the more important, and 2 is probably only relevant in more extreme cases and is a late 1990's link between reticulation and grain clumping, although it doesn't use those terms.


So a question Ron how important was the surface quality in coating films ?

Ian

 

[Hexavalent]

Clumping of a different kind

By request of an APUG member, I am providing the following information regarding "clumping" within colloids, but of a slightly different type.

There exists a large body of work on Chicken Soup. In 1972 a groundbreaking paper was appeared in "Popular Potage" (Boyardee et al) describing the intertwining of long-segment noodles. Unforutately, I don't have access to this magazine as it is somewhere in storage. Further studies by Boullion and Stock showed that Boyardee's original research was flawed due to the presence of mobiusform noodes ("spaghetti-O's") in the samples. Lipton suggested that electrical potentials within soup are the cause of noodling-mingling. As Lipton is primarily a manufacturer of rapid-access (Cup-O-soup) products, one must question the authenticity of their research. Campbell insiders have informed me that after the switch to polymer-lined tins, the currents generated by opener-can bimetallic junction have been eliminated, and yet there are occasional reports of noodle-mingling and vegetable-clumping. It is very difficult to reproduce many of the earlier experiement due to the vague procedural terminology such as "partially cover", "simmer gently", "stirring occasionally" etc.,

Boyardee also investigated "Intersupcession in Tubular Carbohydrate Extrusions", a very rare, but unpalatable phenonemon in over-cooked Canelloni. In recent years, Aspic and Terrine studied cubed vegetable distribution in gel-phase soups, but their findings could not be solidified.

This does not directly address the original issue of carrot-clumping, but it is sufficient to divert the discussion thread and introduce another straw-man.

 

[Photo Engineer]

How come no one at Kodak that I worked with ever heard of #1 before?

How come Ross and other say that the stresses cause not more than a 2 micron shift laterally?

How come no one has heard of #3 at Kodak, but have heard of small imperfections on the surface. In fact, we introduced imperfections in the form of matting agents for retouching and we used to remove imperfections in prints by Ferrotyping after processing.

The surface quality is very good all things considered. Look at any brand of film, from the emulsion side and you will find that it has a dull matte finish, not a high gloss. This is due, in part, to these imperfections and you can see it even in films that are 100 years old as well as modern films. Remember the old darkroom trick of identifying the emulsion from the base by the matte look? That is due in part of the small imperfections. See the Ross cross sections showing how gelatin expands upwards or contracts downwards. This leads to vertical bumps in some cases with films. Paper has less variation due to emulsion size and layer thickness.

I might add that the contraction or expansion is related to density so in all photographs you have a fine relief image. I thought you knew this! Sorry. Kodachrome is an extreme example and has no reticulation problem ever reported despite the "severe" strain of the Kodachrome relief image effect.

PE

 

[Photo Engineer]

Ian;

That is hysterical! Thanks.

PE

 

[Ian Grant]

Ron, I'll provide the most relevant references when I've finished sifting through them but I can tell you that Kodak are/were fully aware of points 1 & 2, rather difficult for them not to be really The Patents & published articles are all Eastman Kodak documents not third party.

What is interesting is that Kodak constantly refer to internal Reports and private messages in research articles, I don't see that as a conspiracy theory as someone else suggested, rather just good commercial secrecy.

Ian

 

[Athiril]

It's well known that classic reticulation causes grain clumping, it's lesser form micro reticulation also causes grain clumping. Micro reticulation manifests itself as excessive grain - grain clumping.

Yes classic reticulation is a gelatin layer fault, micro reticulation occurs before that stage is reached but is also caused by swell & contraction of the gelatin.

The terms were coined many years ago.

There can be other reasons for excessive grain clumping, in appropriate developer choice although the grain in films like Tmax & Delta is more a product of the emulsion and is less dependent on the developer used. This is what Alan was talking about.

So not all grain clumping is micro reticulation, but all micro reticulation is seen as a form of grain clumping.

Ian

Can you prove that there is a force acting between the silver particles, so that attraction/repulsion/adhesion/adsorption would occur between contraction/expansion?

Because it sounds like to me that this would violate laws 1 and 2 of thermodynamics.

It sounds like this is a superposition effect of the SNR.

 

[Ian Grant]

A relevant Kodak document shows that the swell in the surface layer is different to the contiguous layers, this is why you can get get reticulation in the surface layer.

Kodak have published a document showing that there's movement of silver particles due to differences in surface stress. While the effect may be similar they don't say it's due to "attraction/repulsion/adhesion/adsorption" just measurable stresses. It's an academic paper more to do with how they are measuring the stress, any references are to internal documents.

I've never thought the micro reticulation effect is a force acting between Silver particles, just a form or reticulation at a lower level.

Ian

 

[Athiril]

Any such movement requires a conversion of energy.

 

[Tim Gray]

This conversation has really gotten strange. Why not just provide the references now? OR if you insist one waiting until after you've read them, postpone further discussion until after you are done and willing to share them. To hold onto the references until after you are done reading AND to continue to discuss while mentioning the material in the references doesn't seem to be making this a productive conversation.

 

[Photo Engineer]

I am quite well aware of Kodak patents on the use of polymers and chicken gelatin to relieve swell and stress in superposed emulsion layers. I knew one of the patent authors quite well in fact. Yes, films can still reticulate given enough energy in terms of large temperature shifts, and yes I know that even at the present time work continues to improve the impressive resistance to reticulation that modern films have.

All of this taken together does not however, prove that there is grain migration, grain clumping and micro reticulation in one or more products from any company. The reports merely show that they were working on a given problem, not that the problem was to be found in a current product if it was processed in the recommended work flow.

Tim has a good idea. The parallel thread has shown that no reticulation or clumping can be demonstrated with a given Ilford film. I have made suggestions there to use T-Max to satisfy Ian Grant, but as of this point, he has not commented in that thread in any way. He may have since I last checked late last night.

PE

 

[Ian Grant]

I am quite well aware of Kodak patents on the use of polymers and chicken gelatin to relieve swell and stress in superposed emulsion layers. I knew one of the patent authors quite well in fact. Yes, films can still reticulate given enough energy in terms of large temperature shifts, and yes I know that even at the present time work continues to improve the impressive resistance to reticulation that modern films have.

PE

I didn't comment on the other thread Ron because I didn't expect to see much happen, and the author comments that's what I also suggested to him would be the case as well

Ilford films are very well hardened and have been for many years - well all the ones I've used anyway which is all but SFX200, as are almost all Kodak films, particularly since they reformulated Tri-X etc about 6 years ago. You'd have to test Tmax 400 & the new TMY2 to see if there's a difference.

I doubt very much that Micro reticulation is seen as frequently now with films from the major 3 companies, Fuji, Ilford & Kodak, compared to when the Darkroom Techniques article was written in the mid 1980's (after the release of Tmax).

What you've not accepted in this thread Ron is that there can be surface reticulation, rather than full blown reticulation, and it's something you must be aware of, it's been an issue since the introduction of colour & B&W RC papers which affected print Gloss etc, although largely in the past now. Both Kodak & Fuji have Patents that I'm sure you already know that refer to surface layer reticulation.

Kodak's grading reticulation from slight through to objectionable and then severe only comes about when they began testing new hardeners and super coat layers, it was used to visually grade reticulation during research on print film, and there are references to reticulation in the surface layer. Kodak still state that print film reticulates in their technical data.

I rather suspect Ron that you're being obdurate in these threads and that in fact what you refer to as "Yes, films can still reticulate" is far closer to what has been called Micro reticulation than you think.

It seems we have two extremes of reticulation, full blown reticulation "the dried lake bed effect" right through the emulsion to relatively mild "surface reticulation", and a progression between the two. However with the new hardeners full reticulation is almost impossible to generate but excessive grain isn't according to some.

Is there grain clumping ? Grain migration ? There's nothing to indicate that, however if the surface layer reticulation goes deeper and affects the silver bearing layers (which often have a different swell rate - up to 10%) then there would be an increase in apparent graininess.

Ian

 

[Photo Engineer]

"Kodak" classification of reticulation

When I was working on polymers with Ned Ponticello, we found that not only did the polymers tend to form micelles apart from gelatin (depending on composition of the various polymers used), but also they apparently formed intertwined species with the gelatin. Some of these formed hazy coatings.

These polymers did not coat well, did not chill set well and did not harden well in every case. So a search was undertaken to categorize various polymers and their capacity to coexist with gelatin, harden and resist reticulation.

In order to evaluate this, a visual scale was established that is quoted in the appended patent. It has nothing to do with micro reticulation or grain clumping. When you saw reticulation with some of these polymers, you could even FEEL it with your finger. If you wish to see some of work similar to this, then search for some of my patents.

You will find though that these polymers were never used in production (AFAIK) due to expense and hardening capacity. In fact, during this work, Ned and his co-workers found one of the monomers to be a carcinogen and the work had to change direction. You will see that probably if you compare the polymers that he and I worked on and those in the appended patent.

When the monomers were changed, the work had to just about start over. Then the work was pretty much closed down as much of the polymer work then went into image transfer and solvent coatings.

So, the A, B, C, D .... ratings here were macro, subjective and made up for the purposes of comparison within this patent. It revealed some important issues, but the rating system was not used commercially as far as I can determine.

My bottom line is that this patent has no relationship to any of the subject matter at hand as described in the post by Ian Grant earlier in this thread.

PE

 

[Ian Grant]

You still don't say anything about "Surface reticulation" and that the key to Micro Reticulation.

I hadn't had time to see or find Ned's Patent Quite different to those I've been looking at, but still shows Kodak using visual classifications. We'd get to the bottom of these issues if you were less belligerent.

Ian

 

[Photo Engineer]

I knew him as "Ned" but you can call him Ignazio or preferably Dr. Ponticello. How's that?

I have no need to go on. I have shown that one reference you cite is meaningless in either context you have claimed. There are references to reticulation in making photo resists and Kodak references to chicken gelatin, but these don't relate directly to the subject at hand. It would be best for those who favor these explanations to demonstrate them rather than cite irrelevant works.

BTW, you must have seen this patent as it cites the rating method you describe in a previous post.

PE

 

[Ian Grant]

I've not given any references yet Ron, so don't jump to conclusions, because they are usually wrong.

Earlier in this thread you quoted from what you said was my reference, and I'd never seen the document. What are you trying to hide ?

Just why won't you acknowledge my questions about "Surface reticulation", something you MUST know about. You are hiding something, there's something in those Internal Reports & Private messages referenced to in Research Papers.

I'll state again there's two extremes of Reticulation full, the dried lake bed effect and then surface reticulation, and stages in between.

Ian

 

[Photo Engineer]

Ian;

There are surface irregularities which I have referred to before. They create the common haze that I have also referred to earlier and which distinguishes ALL emulsion surfaces from base surfaces as you well know.

In a Dupont patent, they refer to surface haze and equate it to surface reticulation caused during coating and eliminated by their invention. Basically it was bad drying conditions during coating in the first place that caused it. You do not have to have reticulation during coating or processing except with bad conditions. They do not show any examples of reticulation in that patent, they just call it that and quantize it by haze measurements.

I have acknowledged these effects now in several posts, but you seem to ignore my comments because I have pointed out facts about them which don't fit your arguments.

However, to be fair, you have ignored my request to post your (or any) examples. Surely you or a friend who has seen it can scan and post a sample? That should be very simple while you digest all of your references.

PE

 

[Photo Engineer]

I've not given any references yet Ron, so don't jump to conclusions, because they are usually wrong.

Earlier in this thread you quoted from what you said was my reference, and I'd never seen the document. What are you trying to hide ?

Ian;

Regarding the above......

You referred to and enumerated a so called Kodak reticulation rating system and I gave the reference quoting it and showing its application to MACRO Reticulation. This was also the feeling of at least one other APUG poster.

So far, it seems that I am hiding less than you are.

Stating that my conclusions are usually wrong is a rather direct attack, as well as being insulting.

PE

 

[Ian Grant]

Ian;

There are surface irregularities which I have referred to before. They create the common haze that I have also referred to earlier and which distinguishes ALL emulsion surfaces from base surfaces as you well know.

In a Dupont patent, they refer to surface haze and equate it to surface reticulation caused during coating and eliminated by their invention. Basically it was bad drying conditions during coating in the first place that caused it. You do not have to have reticulation during coating or processing except with bad conditions. They do not show any examples of reticulation in that patent, they just call it that and quantize it by haze measurements.

I have acknowledged these effects now in several posts, but you seem to ignore my comments because I have pointed out facts about them which don't fit your arguments.

However, to be fair, you have ignored my request to post your (or any) examples. Surely you or a friend who has seen it can scan and post a sample? That should be very simple while you digest all of your references.

PE

Re read this thread I haven't ignored your request at all. I have my friends 3 Tmax 400 120 films in the UK, they are so grainy he just left then after some initial prints. i actually looked at them on the 9th of this month, I was packing away darkroom stuff before returning to Turkey .

As he had the films off me & never paid for them I'm quite happy to send samples. (He's an APUG member anyway but has never Posted except saying he was a new member).


There's a need to step back & re-think.

Kodak, Fuji and now you say Dupont (i've seen their Patents) say there's surface reticulation, Dupont's YOU SAY from coating, Kodak & Fuji's from processing. Agfa's are downloaded ready to read


Micro Reticulation fully explains all I've seen from slight variations to major variations due to temperature controls, so does surface reticulation which Kodak & Fuji say occurs.

I've repeatedly said that I think it's a terminology issue, it's just very slight reticulation.


Maybe you saying "Surface defects" may well equate to "Micro reticulation" or "Surface reticulation". I think it's the degree that really matters.


So your defects are the reported micro reticulation

Ian

 

[holmburgers]

If I may interject....

I'm sorry, but I don't think anything is being solved here. If it's semantics, then why not leave it at that?

I'd rather see PE in the darkroom working on my 2-color silver-dye-bleach emulsion (just kidding of course!) than this worthless back & forth. I mean.. at least in tennis there's a ball to watch!

 

[Ian Grant]

I think you may be wrong

I'm fairly sure that it's a terminology issue, and can be laid to rest with Ron's help.

Ian

 

[Athiril]

I'm hoping Ian will take a look at my test on the other thread and comment on whether he at least thinks the methodology is reasonable. I'm going to try it with TMAX 400, although one wonders if TMY2 is more resistant than the original TMY.

To me my methodology (although admittedly not perfectly robust from a scientific perspective) should be acceptable to Ian given he said he has seen temperature-induced grain clumping first hand by visual inspection - which to me implies it should be readily observable when it occurs and doesn't require electron microscopy etc.

Michael

I have some TMY2 in th fridge in 120, used to have access to a great olympus bincoluars microscope, and still need lenses for my enlarger.. wouldnt trust the (lack of) resolution of my scanner.

 

[Photo Engineer]

Kodak, Fuji and now you say Dupont (i've seen their Patents) say there's surface reticulation, Dupont's YOU SAY from coating, Kodak & Fuji's from processing. Agfa's are downloaded ready to read

Well, you question me again as to either veracity or the ability to make a conclusion so here it is: http://www.freepatentsonline.com/5128236.html

----- quote ------
ABSTRACT:
.....It is an object of this invention to improve the rate of drying during the manufacture of high speed, photographic silver halide elements. It is also an object of this invention to substantially reduce the surface defects and fog produced in said elements. These and yet other objects are achieved in a process for the drying of a photosensitive element having at least one photosensitive gelatino silver halide emulsion coated on a support, wherein after said layer is coated, said element is subject to elevated temperatures to effect said drying, the improvement comprising the addition before said drying step of an effective amount of a compound taken from the group consisting of ... end quote..

BODY
----- quote-----
.....The sample is then submerged in a glass chamber filled with a clear oil which has a refractive index approximately the same as the sample. The oil fills in the irregular film surfaces which have occurred due to reticulation. A haze measurement is then taken which represents the internal haze. Surface haze is the difference between the total and internal haze measurements. --- end quote---

They offer haze as the defacto existence of reticulation which is unjustified and incorrect. They equate haze with reticulation.

And, they appear to equate coating haze with post process haze. If this is so, then all photomaterials are reticulated (see my earlier comments on this). This is merely the normal irregularities of a coating on the surface of a film and which contains particles. If they are coarse, the haze is higher and if they are fine, then the haze is lower and the gloss is higher.

Their experiment above is very misleading. A goniophotometer would have served them better, I think. At least that is what I have used for haze measurements and I never was taught to equate haze to surface reticulation.

Their invention consists of high molecular weight alcohols incorporated into film to reduce reticulation during coating and incidentally after processing and their only measure is the haze value that the various films have. Well, I have news for them. Just dipping film in silicone oil will reduce haze! (at least to the naked eye)

In point of fact, alcohols and polyols have been used for nearly 50 years to reduce speed and allow higher speed coating. A good example is the use of Sorbitol which is a humectant. Another example is PEG and etc.......

If you accept that HAZE = SURFACE RETICULATION that is fine, but it really is not as the haze is the mild unevenness of all film coatings. It is not cracks in the film surface but it can be if the film becomes too dry. This is one of the purposes served by a surfactant such as Photo Flo.

If you don't believe me regarding haze, go look at the front and back of some processed film and you will see both haze and a mild relief image on the emulsion side of ALL B&W films.

PE

 

[Photo Engineer]

I'd rather see PE in the darkroom working on my 2-color silver-dye-bleach emulsion (just kidding of course!) than this worthless back & forth. I mean.. at least in tennis there's a ball to watch!

I'm doing all of this to AVOID going into the darkroom and do that! I'm thereby leaving the glory to you!

Have fun.

PE

 

[SuzanneR]

This is very tiresome, and maybe it's time for you PE and Ian to take a break, and place the other on "ignore".

 

[Vaughn]

Would it not be easier, if one finds this tiresome, not click on this thread to begin with?