Highest safe temperature for B&W film?

koraks · Oct 16, 2020

DREW WILEY said:
There have been cases in the past where the earlier part of the cut, going to Arista label, occurred prematurely, when the master roll was not yet fully cured, so emulsion defects like fine cracking appeared. This happened with respect to the so-called 200-speed product.

The foma branded product suffered from the same issue.

DREW WILEY · Oct 16, 2020

Yikes.

koraks · Oct 16, 2020

Yes, a pity. I quite like it in 4x5.

Huss · Oct 16, 2020

DREW WILEY said:
I personally wouldn't subject any black and white film to temps above 75F; too much risk of emulsion frilling, especially with EU films. .

I very recently developed Delta 3200 @ 90 with no issues, and Arista 100 pushed to 400 @ 95 degrees with no issues.
95 = 35C

Using Cinestill DF96 Monobath, following their instructions.

DREW WILEY · Oct 16, 2020

Seeming to get away with those kinds of high temperatures on an incidental basis doesn't make it wise as a general practice, or in terms of statistical success. It only informs us that you happened to get away with it in particular a instance, and whether for better or worse, in terms of outcome, we have no means to judge. You might change your mind if an important roll of film gets ruined that way. I have idea why you'd want to risk elevated temperature to do what you refer to as pushing (actually just underexposure / overdevelopment) rather than simply using longer development time or more concentrated developer.

pentaxuser · Oct 16, 2020

I think Drew that we are supplying personal experiences to Bormental because he sees this method of high temp pre-wash as his only solution to his white dots problem.

pentaxuser

Donald Qualls · Oct 16, 2020

So, @DREW WILEY were those labs that were (as far back as the 2000) running my Tri-X and T-Max 400 through an automatic processor at 90+ F (in order to get the T-Max RS developer time down to the processor's developer time), and then presumably turning up the temperature a bit more when I requested a push, only "anecdotally" not having problems?

It is very much worth noting that modern Kodak and Ilford emulsions are much harder than anything you could buy in the 1970s. That said, Foma has a long standing reputation of having a softer emulsion than the "big boys" -- but, as others, I've run Foma in Df96 at 85F without problems.

DREW WILEY · Oct 16, 2020

Why would any AUTOMATED lab deliberately alter their carefully maintained operating temperature for sake of a development tweak? That would be counterproductive unless you were asking for a huge quanitity of film to be done that way. They'd waste a lot of time needing to restore ordinary temp equilibrium before they could do any of their routine orders. Are you sure that is how they did it, or was what involved in a "Push"? If so, it doesn't make much sense unless they had parallel machines running, and even then it would have been a clumsy way to make money. Maybe some dude behind the counter explained it incorrectly. Otherwise, gamble all you want to.
The emulsion of certain Efke films would melt at anything over 75F. I've seen Kodak films reticulate at high temperatures. I've personally had edge frilling of current TMax sheets right at 75F - not the end of the world, involving just the perimeter itself, but an annoying risk of little bits of edge emulsion getting stuck onto the main image.
But I guess some people mistake the term "bootleg" for brewing their hooch inside an old boot, and don't mind swallowing that either. If you can afford the time to tinker with film all kinds of peculiar ways, have at it, and see what happens, and indeed comment. But don't pass it along as reliable general information, because these kinds of variables tend to add up in ways that can result in real headaches. I can't personally afford to follow half-tested rumors. TMax is now running about 9 dollars per 8x10 sheet, and even if only 120 film were involved, there might have been a lot of effort put into exposing that roll. I've come back from hundred mile treks over steep terrain with such rolls. I need predictable consistency, not any "what if" surprises.
But since you did not monitor such temperatures yourself, and deferred the processing to a lab, how can you at this point scientifically state those temperatures were in fact involved. Ever hear of a double-blind test?

foc · Oct 17, 2020

DREW WILEY said:
Why would any AUTOMATED lab deliberately alter their carefully maintained operating temperature for sake of a development tweak?

Slightly off topic, but I have a confession to make!
Two years ago, when I had my minilab, I was inundated with requests for push processing C41 film. Pushing colour negative film seemed to be all the rage on the web. Since I was running a standard Fuji automated processor, push processing would be a real pain and not worth the effort/money (if you want technical details I can give them).

So, with one customer, I decided to accept their pushed C41 film (pushed 1 stop) and at no extra cost.
I processed it as a standard C41 film, scanned the negs, and uploaded the images to Google Drive as requested.
I got an email back from the customer praising my team and me for processing great images and would I develop 6 more films from them?

Of course the moral of that story was: C41 film has very good exposure latitude and don't believe all you read on the internet

pentaxuser · Oct 17, 2020

Here's a question which has just arrived in my head, possibly prompted by foc's post.

What is it about C41 film emulsion that enables it to be developed at 100F but is at best fraught with danger for b&w emulsions and at worst may cause the emulsion to run off the base?

Thanks

pentaxuser

koraks · Oct 17, 2020

The degree of hardening. Most modern b&w films will likely survive 100F though, as long as they're handled carefully.

Donald Qualls · Oct 17, 2020

DREW WILEY said:
Why would any AUTOMATED lab deliberately alter their carefully maintained operating temperature for sake of a development tweak? That would be counterproductive unless you were asking for a huge quanitity of film to be done that way. They'd waste a lot of time needing to restore ordinary temp equilibrium before they could do any of their routine orders. Are you sure that is how they did it, or was what involved in a "Push"?

I'm pretty sure, that's what they specifically told me -- though now I think about it, I'm not certain it was for T-Max; they might have been hand tank processing that (yes, with a push when requested) and the temp rise was for C-41 (it has been close to twenty years, and my memory isn't what it used to be). The way they did it was to run all their pushed film at the end of their work day, after closing the shop, when the machine would have all night (10-14 hours) to get back to standard temp before opening in the morning. So, you could get regular process C-41 films back in an hour or two (depending how busy they were) but for push you had to wait overnight. Then, after they locked the door, they'd raise the temp for Push +1, run all of that film, raise it a little more for Push +2 and run that, and tick it up again if there was a Push +3 request. And they most assuredly did charge extra for the push processing, either B&W or color.

MattKing · Oct 17, 2020

pentaxuser said:
Here's a question which has just arrived in my head, possibly prompted by foc's post.

What is it about C41 film emulsion that enables it to be developed at 100F but is at best fraught with danger for b&w emulsions and at worst may cause the emulsion to run off the base?

Thanks

pentaxuser

Kodak (and others) worked really hard to create film that could be developed safely at elevated temperatures.
The reason?
Higher temperatures mean quicker processing.
Quicker processing means higher throughput.
Higher throughput means more opportunity to make a profit.
There are probably some other technical reasons why the results with higher temperatures are better.

Huss · Oct 17, 2020

DREW WILEY said:
Seeming to get away with those kinds of high temperatures on an incidental basis doesn't make it wise as a general practice, or in terms of statistical success. It only informs us that you happened to get away with it in particular a instance, and whether for better or worse, in terms of outcome, we have no means to judge. You might change your mind if an important roll of film gets ruined that way. I have idea why you'd want to risk elevated temperature to do what you refer to as pushing (actually just underexposure / overdevelopment) rather than simply using longer development time or more concentrated developer.

I did it because I pushed the film and followed the instructions from the mfg as how to do so, including temps.

Arista 100 pushed to 400, developed at 95 degrees:

Ilford Delta 3200, shot at 1000, developed at 3200 @ 90 degrees:

I am extremely happy with the results, and have been following the mfg's instructions and will continue to do so.

DREW WILEY · Oct 17, 2020

So here we're really into an apples vs oranges question. The original question was about higher temps for b&w film specifically, and it got tangled up with C-41 color films, and that, in turn, with shoot from the hip generic opinions about color neg film latitude per C41 pushing. Gosh, maybe it's a generational change, but pushing and pulling once specifically referred to tweaks in the dev stage of color film per se, while b&w workers referred to plus or minus dev instead, and meant something a little different, in which simply more dev time was generally used to increase film contrast and density for one reason or another. In this case you're talking about needing to do it because the neg was underexposed to begin with. But if you want to gamble softening emulsions and making them more fragile using hot water, that's your call. There were logical reasons the industry standardizing on 20C for nearly all b&w films. Rapid automated processing of color film is a different topic.

pentaxuser · Oct 17, 2020

koraks said:
The degree of hardening. Most modern b&w films will likely survive 100F though, as long as they're handled carefully.

Thanks so the likes of Kodak, Ilford and Fuji b&w films are in fact no different from C41 nowadays and would stand 100F So the idea that anything above 75F starts to invite problems in the aforementioned films is now a myth and is a carryover from former times?

So the key question is: how much less hardening does Foma film have by comparison and how much further down the scale of temperature does the pre-wash temperature have to be for safety? Is there anyway to tell from the information in the public domain? If not, I wonder if Foma would respond with an answer?

pentaxuser

DREW WILEY · Oct 17, 2020

Learn the hard way, I guess. What you might get away with in the case of one particular film might turn out a disaster with another type. Back in the old thick emulsion days, my brother would sometimes for fun pass a sheet of Super XX back and forth from a tray of hot developer and one containing quite cold water. The emulsion reticulated, but otherwise remained bonded to the base. That yielded a totally cracked looking image. I suppose there's some goofy App to do that nowadays. Thin emulsions behave differently, but they certainly aren't all the same. When in doubt, experiment with content that's expendable first. Sometimes what you get away with using fresh film backfires with old film. I've seen my share of emulsion and gelatin failures.

Deleted member 88956 · Oct 17, 2020

Once upon a time 68 F 20 C was THE talk in town on B&W development. Times do indeed change. I wonder if microwave oven wouldn't help here. Why not "flash" the neg with some healthy waves and see what that does? Coca Cola has also been effective as eradicator of problems, pre-soak in that, say for 30 minutes?

DREW WILEY · Oct 17, 2020

Huss - you're example with Delta 3200 isn't a push or plus at all if you in fact rated it at 1000. I routinely use 800 for this film and dev it in PMK pyro, and could easily achieve that kind of result at 20C using dev time alone. Is that the old Fredrickson's Hardware in SF, or some other city? It is a nice shot.

Donald Qualls · Oct 17, 2020

@DREW WILEY , use of the terms "push" and "pull" predates common use of color films -- these originated with, IIRC, press photographers in the days when the up-to-date were using Speed Graphics and the like with 4x5 sheet film, while those who were a little behind the time might still be using glass plates in the previous generation of cameras (this would have been before WWII, maybe closer to WWI). You'd either "push" the film in the developer for longer than normal, or "pull" it out early; this was very common in the days of ortho films where development by inspection was the rule. These were the exact same techniques that Adams and Weston etc. called "expansion" and "contraction" or "plus" and "minus" contrast development, just different words. Pushing color became common after color film became common in the 1960s to 1970s.

And though B&W operators are more likely to push film by increasing development time, when you don't have to worry about differential development of multiple layers, time and temperature are easily traded off one for the other -- the rule I've used for years is 4% change in time for each degree F change in temperature -- with the caveat that hydroquinone developers lose activity much more rapidly when temperature drops below 60F. So, if you need a push that calls for 20% extra development time, you can avoid resetting your timer by warming up the chemicals by 4.8 degrees or so (not 5 degrees, quite, because it's 1.04 to the power of the temperature differential in degrees -- that is, each degree warmer represents 4% more development at a given time than the previous, so you have to multiply the changes, not add them). Easily done on any simple 4-function calculator, especially to accuracy to support a thermometer that only reads in 1 degree increments.

But I'd be very surprised if you didn't already know all of this.

DREW WILEY · Oct 17, 2020

Of course I already knew all of that, Donald. All of it was generally known long before the 60's and 70's. Maybe it got a little more trendy about then to fool around with color film specs. But there appear to be numerous persons on this forum that toss around such terminology without really understanding the basis. Labs generally have to work within strictly monitored machine settings and crank out volume results quickly. But personal darkroom workers can easily customize things like time and temp at will. Resetting a timer takes about 2 sec. Changing waterbath temp equilibrium takes a lot longer. Even my thermoregulator, which can actually hold temp inside 1/10F, can do so only within a discrete engineered range (I rarely use that device - it's complete overkill for ordinary b&w processing, but is valuable for nitpicky tasks like precisely matched masks or color separations).

koraks · Oct 17, 2020

pentaxuser said:
So the key question is: how much less hardening does Foma film have by comparison and how much further down the scale of temperature does the pre-wash temperature have to be for safety?

That depends largely on how you handle the film. If you're careful, foma will likely survive just fine up to something like human body temperature, although I wouldn't go beyond. But if you're somewhat rough or brisk, the limit is lower. There's no straight answer.

pentaxuser · Oct 17, 2020

If we stick with the subject of the thread which was higher safe temperature for b&w film Huss reports that his Arista 100 film is OK at 95F and more crucially says that this temperature is in the mfg(manufacturing ?) instructions. This I think these instructions are those of the maker of the DF96 Cinestill monobath and not Arista's but Huss can correct me if I have made the wrong assumption.

It doesn't sound as if Cinestill differentiate between different maker's emulsions i.e. this temperature of 95F applies to all films so unless Cinestill has failed to recognise that Foma is the exception, if indeed it is, or has simply taken the chance that no one using Foma films will bother with Cinestill DF96 monobath then the risk may not be there. Indeed Arista 100 which Huss mentions as one of his films is supposedly Foma film anyway.

Matt has given reasons why we now have hardened film, namely because of the necessity of the C41 process superseding C-22 in the early 70s to use 100F processing temperatures instead of the much lower temperature of 75F for C-22

koraks posts also suggest that up to 100F is safe if film is handled carefully.

It would seem that 90F pre-wash is on balance of the evidence a safe temperature to use a pre-wash at.

The appropriate analogy may be one that coincidentally also involves pre-wash, namely the difference between Kodak's and Ilford's advice on the necessity for pre-wash. For Ilford its position is that it is not necessary but will do no harm

Might this not also apply to pre-wash at 90F, namely a pre-wash at 90F is not a necessity under normal circumstances but in the case of a batch of Foma film, Foma itself has recommended a lengthy pre-wash as a solution for what it and we hope is a temporary problem.

Bormental has a decision to make as to whether he accepts a problem of white dots which seem to be less but still there or try a higher temperature to hopefully eradicate the problem completely. I suspect he has already made that decision

We all look forward to the results

pentaxuser

DREW WILEY · Oct 17, 2020

Why does one or two incidental web opinions without any serious scientific testing in relation to them deserve the same weight as decades of industrial R&D behind recommendations standardized by the engineers and chemists behind such products to begin with? There are textbooks on all this, many Kodak technical publications, and so forth. Next someone will probably omit sulfite in their developer and substitute cranberry juice instead, because it's high in antioxidants. That would take care on any white spots too, because they'd be stained red. How did I personally deal with zits on Foma film? Simple. I stopped buying Foma film.

pentaxuser · Oct 17, 2020

DREW WILEY said:
Why does one or two incidental web opinions without any serious scientific testing in relation to them deserve the same weight as decades of industrial R&D behind recommendations standardized by the engineers and chemists behind such products to begin with? There are textbooks on all this, many Kodak technical publications, and so forth. Next someone will probably omit sulfite in their developer and substitute cranberry juice instead, because it's high in antioxidants. That would take care on any white spots too, because they'd be stained red. How did I personally deal with zits on Foma film? Simple. I stopped buying Foma film.

Can I ask where I might read in Kodak, Ilford and Fuji publications that pertain to present their present range of films, information on what temperature is the beginning of a dangerous level for pre-wash? It would sound as if from your experience that the hardening applied to C41 film which enables it to be subjected to 100F does not apply to b&w films is this correct?

Thanks

pentaxuser

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