How important are consistent temps with B&W?

[Ian Grant]

But can you explain to me why temperature variations in stop, fix and wash change grain size?

I just have.

Ian

 

[Kirks518]

There's a world of difference between the actual physical grain size in a processed film emulsion and the actual "graininess" (Kodak's term) of a subsequent print or scan.

Essentially temperature variations have an effect on the surface (super coat) of the emulsion causing surface artifacts, these have been known about since the mid 1920's when wet mounting 35mm negatives for printing was first advocated to get the highest possible quality from miniature negatives, Ctein advocated this as well.

In practice the differences are often barely noticeable but some films in certain developers are far more prone to temperature variations than others. 120 films can be the worst as they usually have a gelatin top coat on both sides. Rodinal is one developer that can cause issue because it contains Hydroxide which can softens emulsions.

Kodak had a major problem when digital minilabs were first introduced because their films didn't scan well (compared to Fuji etc) and prints were excessively grainy, it was down to these surface artifacts. Now you see Kodak advertising how their newer versions of films are more suitable for scanning.

It's not so long ago that lax temperature control could lead to the emulsion just lifting off the base, that can still happen with Fuji 400 in Rodinal (plenty of people posting about it here and on the rest of the web).

Essentially what I'm saying is lax control with one film might be no issue but with others then you run the risk of ruining your images.

Ian

I guess cliveh and I just aren't understanding how the above relates to grain. I don't like grain, and how to reduce grain was going to be a question I was going to pose in a future thread (I seem to ask a lot of questions, so I was going to wait sometime).

What does the temperature differences do to cause 'graininess'? Does it promote clumping of the silver, or something else? If temps are kept within let's say 2°F, will apparent grain size be reduce versus a temp swing of say 5°F? What is happening in the film/gelatin/etc that is affected by the temps that causes the grain?

Thanks for going into more detail, or should I say in a way I understand it.

 

[bernard_L]

But can you explain to me why temperature variations in stop, fix and wash change grain size?

These are two quite separate issues:

1) Is the effect real? Until experimental proof of the contrary is submitted, I'll believe what Ian states. For myself, I have only circumstantial evidence; I have not done A/B tests. But I play safe, because the cost (keeping temp reasonably uniform) is less than the risk (degraded quality).

2) Do we have an explanation for the effect. And even "explanations" come in several varieties: could be a nice, plausible story, could be a watertight case, with experiment and counter-experiment.

 

[Ian Grant]

I guess cliveh and I just aren't understanding how the above relates to grain. I don't like grain, and how to reduce grain was going to be a question I was going to pose in a future thread (I seem to ask a lot of questions, so I was going to wait sometime).

What does the temperature differences do to cause 'graininess'? Does it promote clumping of the silver, or something else? If temps are kept within let's say 2°F, will apparent grain size be reduce versus a temp swing of say 5°F? What is happening in the film/gelatin/etc that is affected by the temps that causes the grain?

Thanks for going into more detail, or should I say in a way I understand it.

Grain in the film and print or scan graininess are different, temperature doesn't cause grain clumping.

Variations in temperature partiucularly sudden changes affect the characteristics of the top layer of the emulsion causing artifacts also known as micro-reticulation this increases the apparent graininess of the prints or scans. With some films the effects can be quite severe. At it's extreme you get full blown reticulation but few films exhibit this these days.

It's forgotten that most films in the 60's were prone to reticulation unless temperatures were kept tightly under control, Ilford significantly improved the Hardening of their films when FP4 and HP4 were introduced.

So to answer the question you were going to ask tight temperature control will help you get the best out of a film in terms of fine grain etc. It's no coincidence that photographers producing consistently high quality work pay particular attention to all aspects of film processing including temperature throughout the process cycle including washing. +/- 1°C or 2°F is actually easy to achieve.

Ian

 

[Old-N-Feeble]

If you have the budget then consider a thermostatically controlled water bath with a chiller. Consistent temperature is very important to avoid excessively large grain and reticulation.

 

[David Allen]

Having seen first hand the difference in quality between two films (Tmax400) from the same batch in exactly the same developer, stop and fixer, same equipment (thermometer, tank etc) I can assure you the difference in quality can be vast.

I have also seen this at first hand and can confirm Ian's observation.

With regard to temperature consistency of solutions for black & white photography, I would suggest the developer is within + or - 5 degrees above or below 68°F and the development time adjusted accordingly. But with regard to the other solutions, unless the temperature variations are extreme, it doesn’t really matter.

I personally consider this to be bad advice because temperature variations in pre-soak, developer, stop, fix and wash can produce an increase in visible grain. I was taught that this phenomenon is called micro-reticulation. Whether this terminology is technically/chemically correct is something that only a photographic scientist can confirm or correct. I have seen many people argue that micro-reticulation cannot exist because it is virtually impossible these days to get films to dramatically reticulate if you want this effect. However, my interpretation is that the 'reticulation' part of micro-reticulation is probably what people are focussing on rather than the effect that it seeks to describe - namely an increase in visible grain resulting directly from temperature variations in the processing sequence.

Having, in the past, had the unpleasant job of having to print for others I can definitely state that this phenomenon - whatever the correct terminology is - does exist and gives good grounds for tightly controlling temperature throughout the processing sequence. When I worked for good old British High-Speed Rail, all photographers used Hasselblad equipment, Tri-X processed in D76 at 1:1. Every photographer was responsible for processing their own films in accordance with the subject matter that they had photographed. I was then responsible for printing all of the films (such as 10 copies of each negative for the engineering department or 200 copies of the best negative for a press release, etc) and the difference in grain (and technical quality) was huge ranging from negatives with the good tight grain pattern one would expect from Tri-X in D76 through to negatives that looked like they had been made with Orwo rated at ISO 32,000.

The difference in grain was simply down to how much care the photographers took over processing their films with some being very fastidious and others developing films where the only 'control' was how long it took them to smoke a cigarette.

Perhaps more pertinent to this thread is to ask the following question: "Why, when it is so simple to control the whole processing sequence (for example using the example in my thread #12 or by using a water bath to bring all chemicals to the same temperature, etc) do so many people not do this?"

It is truly something that I can't fathom. In my photography, I invest a lot of time walking around finding images that I want to make. Why would I then want to process them sloppily? - after all, it only takes roughly half an hour to process a film even if you have to invest some time getting all of the chemicals at the correct temperature.

What does the temperature differences do to cause 'graininess'? Does it promote clumping of the silver, or something else? If temps are kept within let's say 2°F, will apparent grain size be reduce versus a temp swing of say 5°F? What is happening in the film/gelatin/etc that is affected by the temps that causes the grain?

I can only answer with "I do not have a clue why this occurs" (i.e the scientific reasons). However, I can clearly state from my own experience that it does happen. As it is a variable that can be easily controlled, why take the risk of producing less than perfect negatives?

Bests,

David
www.dsallen.de

 

[Ian Grant]

David, I think what's missed is the Graininess of the prints or scans that's caused by the surface artifacts of the emulsion surface (gelatin coat) is the combination of the inherent grain of the film along with the irregularities of the film surface.

To ensure negatives that scan better Kodak had to try to eliminate the problem particularly with colour films which were increasingly being scanned. The top coat of the emulsion needs to be a smooth as possible. That top coat of gelatin is in the optical path and has an effect on the printing quality in terms of graininess if it becomes more irregular.

You can sometimes see the effect on Glossy RC papers as well, the gloss becomes blotchy or dull.

Ian

 

[David Allen]

Hi Ian,

just to make clear (I should have done this in my post) all of my comments relate solely to a fully wet workflow. I have read about problems with scanning negatives but have never scanned a negative in my life. Where I need a digital version of an image (such as for my website or to send to magazines) I re-photograph my prints (which have already been fully adjusted for exhibition) with a digital camera.

Bests,

David.
www.dsallen.de

 

[cliveh]

Reticulation is a phenomenon related to gelatin and not the silver grain and with modern emulsions it is very difficult to achieve. The emulsion will either reticulate or not at a given temperature. Micro reticulation is a figment of one’s imagination.

 

[Old-N-Feeble]

Increased grain due to inconsistent temps is not a figment of anyone's imagination. What causes it I don't know. What I do know is it does exist.

 

[Ian Grant]

Reticulation is a phenomenon related to gelatin and not the silver grain and with modern emulsions it is very difficult to achieve. The emulsion will either reticulate or not at a given temperature. Micro reticulation is a figment of one’s imagination.

Believe what you want Clive that's your choice, it won't stop people getting poor results from sloppy processing due to lack of consistent temperature control.

On the other hand others might be wise to improve their temperature control at all stages of the process to ensure they get consistent high quality results.

Ian

 

[Ian Grant]

LFA Mason (of Ilford) in his book "Photographic Processing Chemistry" edited by GIP Leneson (Kodak) discusses "Reticulation", he then goes on to say it's caused by stresses in the top gelatin layer of the emulsion brought about by alternate treatment in baths causing swelling or shrinkage of the gelatin. This can be sudden temperature changes and sometimes severe pH shifts.

He then mentions severe reticulation which is where the surface layer of gelatin cracks and some silver from the emulsion itself migrates to the edges if the relief pattern. So he's saying there's a lesser form of reticulation which is what David and I are calling micro-reticulation, a term used in an article about this in the 80's in Darkroom Techniques.

Mason also links Graininess with reticulation.

Ian

 

[cliveh]

LFA Mason (of Ilford) in his book "Photographic Processing Chemistry" edited by GIP Leneson (Kodak) discusses "Reticulation", he then goes on to say it's caused by stresses in the top gelatin layer of the emulsion brought about by alternate treatment in baths causing swelling or shrinkage of the gelatin. This can be sudden temperature changes and sometimes severe pH shifts.

He then mentions severe reticulation which is where the surface layer of gelatin cracks and some silver from the emulsion itself migrates to the edges if the relief pattern. So he's saying there's a lesser form of reticulation which is what David and I are calling micro-reticulation, a term used in an article about this in the 80's in Darkroom Techniques.

Mason also links Graininess with reticulation.

Ian

I have this book (first published in 1966, second edition 1975) and I believe the text you are referring to is on page 207. I would suggest that the key phrase in his description is ‘stresses giving rise to reticulation.’ He mentions no temperatures and I think it is open to interpretation. I can bend a plastic ruler which puts it under stress, but when I let go it goes back to the original position. If I bend it too far it snaps. An emulsion may swell and contract depending on the temperature of solution, but in severe cases reticulation will occur. Also his reference to silver migrating to ridges is under these severe conditions, which is not surprising, as in this instance you are changing the physical nature of the emulsion.

 

[MattKing]

All of these issues and discussions will become moot if all of your process is allowed to come to your ambient room temperature.

With a half hour or so preparation time and a decent size bucket ahead of time for wash water you are golden.

Just be sure to measure that temperature before developing, and adjust your development time accordingly.

 

[Ian Grant]

Mason's talking about reticulation as an irregularity of the surface of the gelatin, not something that's returned to it's former state. He mentions one common temperature related cause, use of wash water warmer than the processing bath.

Your analogy with a plastic ruler is excellent though, slight stresses cause no problems (so similar to normal processing) , severe stress causes failure (similar to severe reticulation), however before you reach the failure point and the ruler breaks you cause stress patterns in the ruler which remain even after the ruler is straightened and can be seen visibly.

In patents relating to the issue Kodak call what Mason (& Levenson as his editor) term Reticulation or Surface irregularities - "Surface artifacts" - and they use a visual scale to determine the increase or decrease in apparent graininess of prints caused by these Surface artifacts.

So there's no doubt what so ever that there's a type of Reticulation - Surface irregularities - Surface artifacts that exists at a level below severe reticulation and that it has an effect on the Graininess of prints (or scans).

Ian

 

[Ian Grant]

Hi Ian,

just to make clear (I should have done this in my post) all of my comments relate solely to a fully wet workflow. I have read about problems with scanning negatives but have never scanned a negative in my life. Where I need a digital version of an image (such as for my website or to send to magazines) I re-photograph my prints (which have already been fully adjusted for exhibition) with a digital camera.

Bests,

David.
www.dsallen.de

David, I'd added the scanning comments for two reasons, first some people scan their negatives (don't use a darkroom) and perhaps more importantly because it caused Kodak to improve the hardeners in many of their films to improve the results of negatives scanned at minilabs.

Like you for sometime I've re-photographed my Exhibition prints or scanned them, however I've found that I need to use Glossy RC papers to achieve the best results and I now only use FB papers. Now I'm using negative scans as I have no problems matching these to the exhibition prints made from the same negatives in the darkroom and I'm getting much higher quality results. I'm not producing Digital exhibition prints just files for publication, websites etc.

Ian

 

[David Allen]

Reticulation is a phenomenon related to gelatin and not the silver grain and with modern emulsions it is very difficult to achieve. The emulsion will either reticulate or not at a given temperature. Micro reticulation is a figment of one’s imagination.

Oh really? Then why is it the case that I have consistently seen increased grain due to inconsistent temperatures. Am I just bonkers? - seeing what is not there? Sorry, it is not a figment of anyone's imagination. What causes it I don't know. What I do know is that it definitely does exist.

I also do not know what (scientifically) causes it. I just know that it happens. The idea that the phraseology of Micro reticulation is a figment of one’s imagination in terms of the correct scientific description could well be true but, there is no getting away from the fact that the phenomenon does occur.

I go back to my original question: "Why, when it is so simple to control the whole processing sequence (for example using the example in my thread #12 or by using a water bath to bring all chemicals to the same temperature, etc) do so many people not do this?"

Or to put it another way, when enough serious workers have witnessed the phenomenon does anyone want to argue about the semantics??? If someone tells me that XXXX will help my work, I will test it and, if it is true, gladly accept it. I do not give a sh*t about the science because I am only interested in achieving the very best results.

David.
www.dsallen.de

Bests,

David.
www,dsallen.de

 

[cliveh]

Ian, this is an interesting discussion, but again I beg to differ. In these patents do they state at what temperature difference the visual scale starts? If they mention graininess, then they must be referring to the severe effect where physical deformation, thus reticulation occurs, re physical change to the emulsion and migration of silver to ridges. I would also like to remind you that we are now talking about emulsions in 2014 not 1966 and I am not talking about extreme temperature variations in solutions.

 

[removed account4]

ian

i was always taught constant temps but
it was dis-enforced when processing and printing
in someones portrait studio ..
that developer mattered the most
( we used a heat rod to warm developer only)
i made a chart to know times for summer processing
but fixer was always ambient temperature ..
we never agitated in fix ( i think? it was a while ago )
but left the hangers in the tank for x mins ..
and wash was always running cold water out of the tap ...
our film was tri x it wasnt reticulated that i could tell
and not excessively grainy ... ( id enlarge sometimes bigger than 16x20)

this was her technique she taught me
and she had been doing it for over 50 years ...
was she risking reticulation and grainy film?
when i asked her about the temps being all the
same temp she just told me to do as i was told and not
question the tried and true techniques

 

[Ian Grant]

Ian, this is an interesting discussion, but again I beg to differ. In these patents do they state at what temperature difference the visual scale starts? If they mention graininess, then they must be referring to the severe effect where physical deformation, thus reticulation occurs, re physical change to the emulsion and migration of silver to ridges. I would also like to remind you that we are now talking about emulsions in 2014 not 1966 and I am not talking about extreme temperature variations in solutions.

You need to get a bit more up to date. These issues are within the last 2 decade and current not the 1960's.

As much as you care to differ the deeper you dig yourself in to a role of ignorance. Poor temperature control with some of today's emulsions and developers will lead to issues of reticulation,

Fuji Neopan 400 in Rodinal is a prime example, Adox and Foma films another. I've used EFKE/Adox films since the early 70's and once you know how to handle them they give superb results.

If you wanted me to talk about how to handle 60's emulsions there e would be a page of per-hardeners, hardener stop baths, hardening fixers but actually only really FKe films needed them as long as temperature control was tight.

Ian

 

[Ian Grant]

ian

i was always taught constant temps but
it was dis-enforced when processing and printing
in someones portrait studio ..
that developer mattered the most
( we used a heat rod to warm developer only)
i made a chart to know times for summer processing
but fixer was always ambient temperature ..
we never agitated in fix ( i think? it was a while ago )
but left the hangers in the tank for x mins ..
and wash was always running cold water out of the tap ...
our film was tri x it wasnt reticulated that i could tell
and not excessively grainy ... ( id enlarge sometimes bigger than 16x20)

this was her technique she taught me
and she had been doing it for over 50 years ...
was she risking reticulation and grainy film?
when i asked her about the temps being all the
same temp she just told me to do as i was told and not
question the tried and true techniques

The simple anser is with some nfilms nthat works, I've seen it first hand. With others it doesn't



Ian

 

[removed account4]

The simple anser is with some nfilms nthat works, I've seen it first hand. With others it doesn't



Ian

. thanks

 

[cliveh]

Poor temperature control with some of today's emulsions and developers will lead to issues of reticulation,Ian

Let me be very clear here, if you look at my original post I never mentioned poor temperature/time control with regards to development.

 

[nbagno]

I process film in a jobo processor and when the ambient temp and cold water temps are above the 20C that I always process B&W at, I have an extra 1L bottle that fits in the water bath, and which I keep in the freezer - putting this in the water bath drops the bath temp, and the jobo heats, and the 1L bottle gives me a stable 20C water bath for about an hour.

Must try this tip. Thanks

Sent from my SM-N900V using Tapatalk

 

[Ian Grant]

Just to clarify the effects of temperature changes between solutions including the wash water and the increase in Graininess of a film has been known for nearly a century. Jones & Deisch published a paper on Graininess in 1920.

The term "Incipient Reticulation" is used to describe the micro-reticulation of the emulsion's surface coat caused by sudden stresses cause by excessive temperature or pH changes between baths. Interestingly Crabtree of Eastman Kodak also uses the term Incipient Reticulation in his article on Graininess in Cine films where he also describes Kodak's Fine Grain developer for Motion picture films, later sold as D76.

Incipient Reticulation / micro-reticulation can vary in its severity depending on the temperature of pH variation that caused it. It's not what we call conventional Reticulation where the emulsions surface cracks, it is however the very early stages of it.

The surface effect of this early stage of reticulation doesn't alter the size of the grain in the film itself however it does affect the light path and the consequence is increased graininess in prints or scans. It's why you can reduce graininess in enlarging or scanning by wet mounting a negative (or positive) to glass. The technique was first advocated by K.C.D. Hickman in 1927 in the BJP.

So tight temperature control will help prevent an increase in graininess, so is essential to achieve the best possible results

Ian