Grain, Micro reticulation & B&W fim process temperature deviations

Before the upgrade there were two threads where this issue was touched on. In the last a number of APUG membesr chipped in saying they'd had grainer than usual films (same film/developer etc) when they'd paid no attention to temperature control.

This is what John Davies has to say on the subject. John is Britain's top landscape photographer, his print quality from 120 films is 2nd to none, it's outstanding.


"It is also important to control the temperature of all the chemicals during processing and including the final wash. Slight fluctuations in temperature between the solutions will result in slight reticulation which is where the silver halide crystals form larger crystals to give the appearance of larger grain. Greater temperature fluctuations between solutions will result in a greater size of grain. In extreme cases the silver halide crystals form dominant textured patterns"


Here's the link to his website.

John's technique and work is on a par with John Sexton & John Blakemore for his mastery of processing and printing control, with work in many major collections around the world. (He lists the major ones, quite a number, MOMA, New York is one).

The Reticulation John refers to is better known as micro-reticulation or grain clumping, it's the big unspoken secret of high quality neg processing, and it's so simple - minimal temperature deviations throughout the whole Dev/Stop/Fix/Wash sequence.

Note John is referring to small changes.

Ian

Ian, reticulation is a phenomenon related to gelatin and not the silver grain. That quote above is totally incorrect!

Reticulation is caused by temperature changes which distort the gelatin, not the silver. At the point in the grain's lifetime, when you are processing it, it is practically impossible to change the grain size by a mere temperature change.

Grain clumping is another matter. This can take place at any temperature when two grains fuse due to slight migration or silver halide solvent effects. It is such a rare effect that most major texts do not treat the subject at all. Mees does mention clumping, but only in terms of statistical distribution of developed silver from grains as coated.

PE

Photo Engineer said:

Ian, reticulation is a phenomenon related to gelatin and not the silver grain. That quote above is totally incorrect!

Reticulation is caused by temperature changes which distort the gelatin, not the silver. At the point in the grain's lifetime, when you are processing it, it is practically impossible to change the grain size by a mere temperature change.

Grain clumping is another matter. This can take place at any temperature when two grains fuse due to slight migration or silver halide solvent effects. It is such a rare effect that most major texts do not treat the subject at all. Mees does mention clumping, but only in terms of statistical distribution of developed silver from grains as coated.

PE

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No it's TOTALLY correct, grain clumping has also been called micro reticulation when caused by temperature effects because the shrinking & expansion of the gelatin is the cause of the clumping

So please don't get pedantic on what "others" call Reticulation (or Micro reticulation) because YET again you are agreeing the effects happen. I'd say it's better to add the term "micro" to reticulation because it's not the same as classic old style reticulation.

There's no denying that sharp temperature changes increase grain size, and they don't need to be very large at all.

Ian

Photo Engineer said:

Mees does mention clumping, but only in terms of statistical distribution of developed silver from grains as coated.

PE

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When Mees was alive people processed to +/- 1°C through the whole cycle. With the much softer films then if you didn't you got classic big time reticulation the gelatin crazing. And when it came to washing you took the temperature down slowly to the tap water temperature.

Ian

Ian;

Many here on APUG get real gelatin reticulation with modern films by heating the wet film in very hot water and then plunging it into ice water. So far, I hear of no reports of any clumping of grains resulting from this procedure.

Also, Anchell and Troop speculate on whether the heat generated by neutralizing a developer by using a stop bath would cause grain clumping. Well, I have talked to several other Kodak engineers about this and a lot of work was done on reticulation and grain clumping.

It appears that a lot of heat energy would be needed to cause this so called clumping. I don't doubt that something is taking place, but to be accurate, there is reticulation and there is clumping. Most all reports of clumping have come from coating problems rather than process problems, and the consensus is that if there was enough heat applied in the process to cause clumping of grains, then gelatin reticulation would be present as well.

To know what is going on, it would be necessary to know the film and the process and then it would be necessary to analyze the film by cross section photo or electron micrographs. Also, I find it curious that this reference is the only one. If it were an endemic problem we would be hearing about it here and from the manufacturers. Don't you agree?

He should bring this to the attention of the makers of his film and / or process chemistry.

PE

Photo Engineer said:

He should bring this to the attention of the makers of his film and / or process chemistry.

PE

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This is not a theory of John's it's come through dissemination of knowledge via workshops, discussions with consultants working for Kodak and other film manufacturers, and was a belief of St Ansel himself, and preached by Minor White and many others.

Kodak are fully aware that sloppy temperature control increases grain size, but they won't put it in writing.

This isn't the only reference, there was a long illustrated article about it in the 80's in a US magazine. The problem is that all the film companies tests are done to strict temperature controls and there are too many variables of films.developers to be fully tested. In addition most professional photofinishees worked to +/- 0.2°, and pro photographers to +/- 1°C.

The most severe issues arise with Rodinal (because of it's high pH) and Tmax 400 and Acros, but the worst I've seen first hand was TMY in Xtol, the 120 negs were too grainy to be used, and as I've posted before it was film from my batch, my tank, replenished Xtol, fix etc, but I didn't do the processing and was appalled that the photographer only checked the developer temperature just using the rest as it was,

It happens Ron, just because you haven't seen it DON'T dismiss it.

Ian

I once tried to produce the effect but was unsuccessful.

Ian, I would be happy to set up a controlled experiment if you tell me how to produce the effect. What temperature delta between what processing baths would most likely create an visible increase in grain? I have Tmax, FP4 and HP5 at hand and could try Rodinal or D76/ID11.

Ian Grant said:

This is not a theory of John's it's come through dissemination of knowledge via workshops, discussions with consultants working for Kodak and other film manufacturers, and was a belief of St Ansel himself, and preached by Minor White and many others.

Kodak are fully aware that sloppy temperature control increases grain size, but they won't put it in writing.

This isn't the only reference, there was a long illustrated article about it in the 80's in a US magazine. The problem is that all the film companies tests are done to strict temperature controls and there are too many variables of films.developers to be fully tested. In addition most professional photofinishees worked to +/- 0.2°, and pro photographers to +/- 1°C.

The most severe issues arise with Rodinal (because of it's high pH) and Tmax 400 and Acros, but the worst I've seen first hand was TMY in Xtol, the 120 negs were too grainy to be used, and as I've posted before it was film from my batch, my tank, replenished Xtol, fix etc, but I didn't do the processing and was appalled that the photographer only checked the developer temperature just using the rest as it was,

It happens Ron, just because you haven't seen it DON'T dismiss it.

Ian

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Ian;

Have you seen it when you made an effort to generate this effect yourself? I know of no one that has seen this as a function of temperature. Reticulation took place, not grain clumping. I have never seen or heard of this being done successfully. My information from Kodak agrees with Ralph's.

Please give us some indication, other than your words here, that Kodak, Ilford and Fuji are aware of this. I have never seen any mention of it anywhere except in Anchell and Troop. I have never heard of it in internal reports, and I assure you that I have discussed this very problem with Grant Haist. All of the responses say that a lot more heat is needed.

Now, as for high pH, I can agree that this might be possible due to the extreme swell that may take place in the coating. Also in high solvent developers it might take place, but to call it reticulation would be a gross misnomer unless the gelatin was distorted as well, and could be seen to be reticulated in the classic fashion.

And, I remind you, that it takes a bit of energy to move crystals around during processing. It takes more than that needed to reticulate the gelatin. The pH change from an NaOH or KOH developer just might be near that needed but I have to say again that I've never heard of it taking place. And, I remind you that no one on APUG has ever reported it AFAIK.

Something is taking place, I've no doubt. I stated that above and my suggestions for testing.

PE

RalphLambrecht said:

I once tried to produce the effect but was unsuccessful.

Ian, I would be happy to set up a controlled experiment if you tell me how to produce the effect. What temperature delta between what processing baths would most likely create an visible increase in grain? I have Tmax, FP4 and HP5 at hand and could try Rodinal or D76/ID11.

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You were looking for old fashioned reticulation not micro reticulation/grain clumping,

In many ways the terminology Micro-reticulation might be misleading but the term was coined sometime around the 80's, maybe even late 70's, what we are talking about is grain clumping, going from just a slight increase in grain to excessive.

There's too many variables Ralph, type of water, film/developer combination, developer concentration etc. When does the temperature shock take place, how sudden, how much. With sloppy processing we don't know.

PE is in a combative mood, in a previous thread a number of APUG users confirmed their own experiences of excessive grain after poor temperature control but he wasn't at all interested in their comments.

Try Acros in Rodinal that's where other people on APUG bare having issues, also Tmax 400 in Rodinal. I have none with Pyrocat & Acros, because of it's tanning efects but instead I get a tirade about tanning developers being bad for smaller formats from Ron (another thread). Give film a 5° C lower shock a few time, bringing it back up just as fast. That should give great grain It's also inside certain film manufacturers parameters

Ian

Read John Davies comments again not mine. They reflect general opinions from elite photographers in the US & UK, people like John Sexton included.

The initial effects are quite subtle just a slight increase in grain. When you and Haist worked for Kodak all those years ago the data-sheets suggested far tighter temperature controls for B&W processing. We aren't talking difficult to keep to like older Colour processes with their +/- 0.2° C controls although B&W photofinishers used similar tolerances (they used similar process lines).

I can't understand why you are arguing against good practice ? Very odd.

Ian

Photo Engineer said:

Ian;

Have you seen it when you made an effort to generate this effect yourself? I know of no one that has seen this as a function of temperature. Reticulation took place, not grain clumping. I have never seen or heard of this being done successfully. My information from Kodak agrees with Ralph's.

Please give us some indication, other than your words here, that Kodak, Ilford and Fuji are aware of this. I have never seen any mention of it anywhere except in Anchell and Troop. I have never heard of it in internal reports, and I assure you that I have discussed this very problem with Grant Haist. All of the responses say that a lot more heat is needed.

Now, as for high pH, I can agree that this might be possible due to the extreme swell that may take place in the coating. Also in high solvent developers it might take place, but to call it reticulation would be a gross misnomer unless the gelatin was distorted as well, and could be seen to be reticulated in the classic fashion.

And, I remind you, that it takes a bit of energy to move crystals around during processing. It takes more than that needed to reticulate the gelatin. The pH change from an NaOH or KOH developer just might be near that needed but I have to say again that I've never heard of it taking place. And, I remind you that no one on APUG has ever reported it AFAIK.

Something is taking place, I've no doubt. I stated that above and my suggestions for testing.

PE

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I am not arguing against good practice. I am commenting on using the word reticulation and grain clumping in a mannter that appears to be interchangeably and am arguing that I have neither seen nor heard of this happening, not on APUG and not at EK. It was never mentioned in internal reports, nor was it mentioned in the courses taught internally. Reticulation was covered! Obviously, something is going on, but I would expect to see more comments on this in general if it were widespread.

As for John's comments on his web site, well, he says that 120 film has a thinner gel base than 4x5. Hmmm, It has a thinner base than 4x5 in terms of its support, but not a thinner gel base. To go on, this does not make 120 sharper than 4x5. Both film sizes are coated at roughly the same thickness if it is the same product but the film support is different in thickness. Since the support is BEHIND the imaging layer it has little effect on the image.

So, I see what appear to be several comments on his web page that I cannot agree with due to his use of terms or nomenclature or whatever. I think anyone here would agree that 4x5 is sharper (and less grainy) than 120 all other things being equal such as lens quality, process, film and etc.

He also says that finer grained films are harder to control for contrast. IDK about that either. I've never seen the problem myself. I don't think that this can be shown from the curves on the Kodak web site.

But, back to the main issue. Grain clumping should be at issue in C41 and particularly in E6 processing where the temperatures of the tail end solutions are allowed to move by as much as 10 deg F or greater from 100 F. This is further compounded by the fact that coupler droplets could migrate and coalesce more easily at lower energy levels than silver halide crystals which are actually bonded to the gelatin.

So, I think that although something is taking place, it is not what is described or not what it is attributed to.

I repeat again, I subscribe to good processing practices and do not like people being told that I suggest otherwise. I have given an honest opinion on your information from my experience. This neither proves your post nor mine are correct until somone else comes forth with substantive data showing the problem. Even John did not show data on his web site, at least as far as I could see.

PE

I'm just reading this, Ian, and it's clearly you who are in a combative mood. You sound downright cranky.
Where did PE argue against good practice? It's not there.

In the older thread to which Ian refers I mentioned noticing excessive, well increased anyway, grain with TMY2 - 120 format in highly dilute Rodinal. I am very careful with my development and was surprised by it. The ONLY real variable I could think of was that I was not paying attention to my WASHING temperatures. I was using tap water at whatever temperature it happened to be. The water was noticeably colder to the touch than my 70 degree developer.

Ian suggested slowly bringing my film down to temp by using a water jacket before washing. He also suggested making a cup of tea during that time though I'll probably make coffee instead. =) I'm taking a bit of a processing break right now, probably through the end of August. As soon as I test and compare I will report back here. Might do something just to ease my concern/curiosity this week but can't be sure.

I did not notice the effect with my 4x5 standard of FP4+ in Rodinal (because of the smaller grain?). Another reason could be space constraints force me to wash 4x5 differently and my routine - through no design of mine - allowed for a cooling down period though certainly not ideal. I will be more careful in this regard moving forward and compare those results as well.

I mostly make contact prints where this grain increase is not noticeable. My observations were made viewing the film on a light table using a Schneider 8X loupe.

Of course I am no scientist, by any measure, but I do look at things carefully. =)

Shawn;

If I did indeed ignore your previous comments, as Ian has suggested, my apologies. I am very interested in this and would like to follow it through. Please stay in touch as you do this. So far, it seems that the 2 or 3 cases are all with Rodinal and seem to appear in the wash with a rather small temperature change.

Can you give us more information on the fix and stop or rinse? More information on the dilution and agitation during development? Thanks.

PE

I would like to show my ignorance and ask about another possible variable. If the processing is taking place in a room with an ambient temperature three or four degrees different to the processing temperature (higher or lower) then every time liquid is poured out of the tank it will be replaced with air at room temperature. Given the film's large surface area compared to its volume I would think that it would quite quickly get to or near to the air temperature. Pouring in the next liquid in the process would move it back again.

So in theory, even if developer, stop, fix and wash were all at an identical temperature, there could be three stages where the film changes temperature and then goes back again when processed in a hot or cold room.

Possible scenario or just my mind being over active?

Shawn Dougherty said:

He also suggested making a cup of tea during that time though I'll probably make coffee instead.

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I think it only works with tea!


Steve.

Photo Engineer said:

But, back to the main issue. Grain clumping should be at issue in C41 and particularly in E6 processing where the temperatures of the tail end solutions are allowed to move by as much as 10 deg F or greater from 100 F. This is further compounded by the fact that coupler droplets could migrate and coalesce more easily at lower energy levels than silver halide crystals which are actually bonded to the gelatin.
PE

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Interesting you think that, I'd expect just the opposite. The dyes will stay with the emulsion as it shrinks or expands whereas the silver grains coagulate. maybe both happen but speed is faster with the silver.

Ian

It was a different thread in which the topic came up a week or two ago. Was actually off topic for the thread. I'm simply interested in a resolution. It's killing me that I need to take a break right now (busy with family things and recent temps here force me to process VERY early in the morning - I'm a night time processor by nature...)

My 120 TMY 2 Routine.... Rodinal, 5:900 for N rolls (5ml of Rodinal in 900ml of distilled water). 1 roll in the bottom of a two reel tank. I process for 40 minutes, agitation the first minute then for about 20 seconds at 10min, 20min, 30min. At 40 minutes I dump and add Sprint fixer at 2:8 The fixer is usually within 2 degrees of the developer (I will be certain it is the same moving forward). I fix for 10 minutes with agitation the first minute then every 30 seconds. At this point I start washing in tap water while I add a half cap full of Zonal Pro wash to 1000ml of water and agitate it for 2 minutes. I then continue the wash. At the end I use a weak solution of photo flow mixed with distilled water for about a minute before hanging (this is done at 70 degrees so I guess it's a SECOND temp shock? Oh boy....).

I think that covers it....

Steve Smith said:

So in theory, even if developer, stop, fix and wash were all at an identical temperature, there could be three stages where the film changes temperature and then goes back again when processed in a hot or cold room.
Steve.

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NOO!!!! No more variables to think about, please!!!! Actually that sounds reasonable to me...... but I hope it is not the case!

Photo Engineer said:

I am not arguing against good practice. I am commenting on using the word reticulation and grain clumping in a mannter that appears to be interchangeably and am arguing that I have neither seen nor heard of this happening, not on APUG and not at EK. It was never mentioned in internal reports, nor was it mentioned in the courses taught internally. Reticulation was covered! Obviously, something is going on, but I would expect to see more comments on this in general if it were widespread.

PE

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Ron. I've REPEATEDLY said it's not my terminology but the term Micro Reticulation for grain clumping has been in use for around 30 years, and I've always made the meaning clear. That's not you or me and our opinions that terminolgy was given by others.

I wouldn't have made the post if I wasn't 100% sure that John's comments are completely right, and back up what I've posted before and learnt from experience. I have discussed the subject with senior people (sales & research) from two film manufacturers in the past (in the 80's), and also I know others have done the same with Kodak.

Every time you post a reply you pack it full with irrelevance: It's always been known that very slow FG films like Pan F and Pan X were harder to control in terms of contrast, both Ilford & Kodak acknowledged that fact in their literature, and many here on APUG would fully agree. Agfa APX 25 was an exception but those comments of yours are unfair. Don't take John's workshop notes out of context, when larger film refers to finer grain in print.

Ian

There's no sweating to do. Relax

Just keep all temperatures within 1° C or as close as possible. It's no big deal and is very easy to do. If they start all the same and drift down no big deal.

For some reason Ron's arguing against me without always also saying it's good practice to run a tight process.

Ron's not wrong, what happened was a lassitude set in because films became better hardened, and some people became lax on temperature control. Normally increased grain will be minor noticeable with 35mm , but not noticeable with 120 or larger, But in extremes the 120 is excessively grainy, 35mm unusable, but we are talking as you head out to extremes.

I'm talking 5°C swings, that's enough to kill you in real life (body temperature) which begins to put things in better perspective, so that has to effect an emulsion, yet is in tolerance according to some manufacturers.

Don't get paranoid I'm talking more than your deviations

Ian

Michael R 1974 said:

In the first thread on this that was making me very paranoid about my processing, I asked specifically if Ilford had any data on Delta films. The reason I asked is that in their literature they seem to always say temperatures should be kept within +/-5C, which according to Ian and the articles he references, would be way too wide a swing for high quality negatives. My question to Ilford was whether +/-5C is the outside limit for merely acceptable negatives, or if it is a range within which the highest negative quality can be achieved (as we know the literature is often written by marketing and accounting, rather than the engineers). I think Simon Galley was going to look into whether Ilford had any testing or data on the subject but I haven't heard back. Going back to that original thread, I raised alot of concerns about my own work because I had sometimes encountered temperature swings of +/-2C, and was now worried I was getting grain clumping due to my own subjective opinion that my Delta 100 negatives are too grainy. While my negatives seemed fine to John Sexton when he examined them under magnification at a workshop, the thread was still helpful in the sense that it caused me to further refine my processing so that I can get everything including the wash to within +/-1C. I can't hold things any more accurate than that. There is always some small drift. In addition, no matter how many tempering baths you have going, my thinking is that at the interface of developer and emulsion, some small temperature increase is probably unavoidable since I believe the reduction reaction is slightly exothermic to varying degrees. Now it seems the jury is out again? Every time Ian Grant talks about this I start to sweat and become paranoid again. What good is +/-0.2 degrees as an achievable margin? It's not possible. Even +/-1C is a stretch. If todays films have such a low tolerance for temperature drifts before image quality begins to suffer, I'd really like for Ilford or Kodak to tell me that right now, once and for all, because if this is the case I'm wasting my time trying to make high quality 35mm negatives. I should be using 8x10 film and contact printing in that case, so that grain clumping is relegated to a non-issue. This stuff makes me nuts and I don't know who to believe anymore. To be perfectly honest, I need a scientist to tell me about this, not photographers. Ask ten excellent darkroom photographers about anything, and everyone tells you they see something that is or isn't there. I find this nonsense all the time when I read Adams. He wrote good books to learn from if you're a beginner and trying to avoid major mistakes, but once you get into the details his "observations" regarding the behavior of materials are subjective.

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Michael R 1974 said:

In the first thread on this that was making me very paranoid about my processing, I asked specifically if Ilford had any data on Delta films. The reason I asked is that in their literature they seem to always say temperatures should be kept within +/-5C, which according to Ian and the articles he references, would be way too wide a swing for high quality negatives. My question to Ilford was whether +/-5C is the outside limit for merely acceptable negatives, or if it is a range within which the highest negative quality can be achieved (as we know the literature is often written by marketing and accounting, rather than the engineers). I think Simon Galley was going to look into whether Ilford had any testing or data on the subject but I haven't heard back. Going back to that original thread, I raised alot of concerns about my own work because I had sometimes encountered temperature swings of +/-2C, and was now worried I was getting grain clumping due to my own subjective opinion that my Delta 100 negatives are too grainy. While my negatives seemed fine to John Sexton when he examined them under magnification at a workshop, the thread was still helpful in the sense that it caused me to further refine my processing so that I can get everything including the wash to within +/-1C. I can't hold things any more accurate than that. There is always some small drift. In addition, no matter how many tempering baths you have going, my thinking is that at the interface of developer and emulsion, some small temperature increase is probably unavoidable since I believe the reduction reaction is slightly exothermic to varying degrees. Now it seems the jury is out again? Every time Ian Grant talks about this I start to sweat and become paranoid again. What good is +/-0.2 degrees as an achievable margin? It's not possible. Even +/-1C is a stretch. If todays films have such a low tolerance for temperature drifts before image quality begins to suffer, I'd really like for Ilford or Kodak to tell me that right now, once and for all, because if this is the case I'm wasting my time trying to make high quality 35mm negatives. I should be using 8x10 film and contact printing in that case, so that grain clumping is relegated to a non-issue. This stuff makes me nuts and I don't know who to believe anymore. To be perfectly honest, I need a scientist to tell me about this, not photographers. Ask ten excellent darkroom photographers about anything, and everyone tells you they see something that is or isn't there. I find this nonsense all the time when I read Adams. He wrote good books to learn from if you're a beginner and trying to avoid major mistakes, but once you get into the details his "observations" regarding the behavior of materials are subjective.

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Michael

If you can control your processes within 1°C forget about this thread and continue to take pictures!

Ian;

You asked me to look again at that web site you referenced. To put it in perspective, I commented on several dubious comments regarding technical aspects of photo science. I used that to show that your reference may not have all of the facts straight in these technical matters and in fact had presented no evidence for his statements.

For example, regarding film speed vs contrast, look here: http://www.kodak.com/global/en/professional/support/techPubs/f4016/f4016.pdf for a comparison of Tmax 400 and Tmax 100 films , starting at page 16. The answer to contrast control vs film speed is based on developer used! You can get virtually any contrast or rate of development you wish with any film just based on developer. So, the fact that someone says that fine grained films are contrasty, well, the data and my own long experience just does not support that conclusion as long as you use the right developer and development time as suggested by the manufacturer.

On the other posts here, +/- 2 degrees F or even 4 degrees F (which would be roughly 1 and 2 degrees C as an approximation) is virtually nothing to films from Kodak, Ilford and Fuji, as long as they don't take place in the developer, as this can lead to over or under development. Otherwise, we would be in really serious problems here guys. Even color film allows up to 10F or more, as I said, with no problem!

Remember that you also have evaporative cooling when you pour out solutions and the humidity is low. Just kidding! That can take place but it too is virtually nothing.

No, several degrees should not affect film in terms of grain or reticulation. If it does, something else has gone on.

Now, on another note. Low buffered developers such as a dilute Rodinal might be at pH 11 - 12 or thereabouts. I have not measured it, but I did do some work on low buffered high pH developers to induce edge effects when I was at EK. I measured the pH of the coating and without agitation, the pH in the coating fell from around 12 to 4.5 (the isoelectric point of the gelatin used) due to the acid produced by the developer. With agitation, the pH did not fall this far or hardly at all. So, there may be a rather huge pH change involved. IDK.

So, as I noted above, a high pH developer may be part of this issue, if the problem even exists.

If John Sexton examined some negatives and said there was no problem, I would respect his judgment! Especially since he is mentioned by Ian as having seen this problem before.

So, the bottom line is this. Current B&W films are built to withstand about 5 degrees F swing in temperature during the process. Color films can stand even more. Kodak lists development and process temperatures for B&W films up to 80 degrees F, but above about 75 F, I suggest a prehardener. My own experience says that within that range the variation or swing between solutions should be less than 5 degrees.

I remind you again that APUG members have had difficulties even getting any reticulation with modern films and grain clumping should be even more difficult.

Ian;

I've do not "accuse" you of anything but using the term incorrectly. I do not accuse you of originating it, just perpetuating it. And, the use of terms, if used incorrectly by many people still does not mean that they are right to be used that way. Otherwise, how can we communicate?

As for the color film, your belief that things would go the other way would be natural if you had not studied the matter. You see, if silver clumps, so do the dye clouds. That is just for starters. The droplets of coupler and dye are somewhat like little tiny soft balls that can move through the gelatin, but silver is chemically bonded in a method called peptization to the gelatin. See here: http://en.wikipedia.org/wiki/Peptization for a generic description. If you precipitate silver with too little gelatin, you get clumps and if it is really low, you get aggregates forming that actually look and feel like sand. This is a major topic in our internal courses and one of the most significant means of getting clumping as I mentioned earlier.

PE

RalphLambrecht said:

Michael

If you can control your processes within 1°C forget about this thread and continue to take pictures!

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Or close to +/- 2° C at worst

I think what we are really talking about is unmeasured or judged temperatures after development, and while there's a very slight shift in graininess with some films there can be excessive shifts with others.

My gut feeling based on experience is it always slight with Ilford films, and TMX, and all Agfa films. However TMY (old & new) is very prone to increased grain clumping in Xtol, others say so is Acros in Rodinal but that's not my experience in Pyrocat.

Ian

Photo Engineer said:

On the other posts here, +/- 2 degrees F or even 4 degrees F (which would be roughly 1 and 2 degrees C as an approximation) is virtually nothing to films from Kodak, Ilford and Fuji, as long as they don't take place in the developer, as this can lead to over or under development. Otherwise, we would be in really serious problems here guys.

No, several degrees should not affect film in terms of grain or reticulation. If it does, something else has gone on.

Now, on another note. Low buffered developers such as a dilute Rodinal might be at pH 11 - 12 or thereabouts. I have not measured it, but I did do some work on low buffered high pH developers to induce edge effects when I was at EK. I measured the pH of the coating and without agitation, the pH in the coating fell from around 12 to 4.5 (the isoelectric point of the gelatin used) due to the acid produced by the developer. With agitation, the pH did not fall this far or hardly at all. So, there may be a rather huge pH change involved. IDK.


So, the bottom line is this. Current B&W films are built to withstand about 5 degrees F swing in temperature during the process. My own experience says that within that range the variation or swing between solutions should be less than 5 degrees.


PE

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I'm feeling better.... I did not always experience the increased grain, upon further inspection just now the increased grain seemed to happen mostly in the winter. My tap water now is somewhat cooler but it is quite a bit cooler in the winter!

I will be more careful and use the water jacket cooling and other suggestions to slowly decrease film temp to wash temp.

The fact that the winter rolls are the slightly grainier ones suggests it is indeed water temperature and not my highly dilute Rodinal as that was constant in all seasons. Plus, Ron says highly dilute Rodinal with a minimum of agitation, which I use, lowers the PH somewhat. Do my assumptions sound reasonable?

I will run tests as soon as I can. I'll just have to bite the bullet and get up really early a couple of days this week.

THANK YOU to everyone involved, and to Ian for bringing this to my attention in the first place. APUG kicks ass!

Shawn

Ian Grant said:

I think what we are really talking about is unmeasured or judged temperatures after development, and while there's a very slight shift in graininess with some films there can be excessive shifts with others.

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Yeah, that's got to be my problem. That winter tap water was quite a bit cooler and I was just judging not measuring. Feeling a little silly.... so careful with all these things and let that slide!!!!!!!!!