How important is temperature in developing B&W film?

How important is temperature in developing B&W film?

  • Yes, I always ensure it's exactly 20 deg C/68 deg F

    Votes: 152 58.2%
  • Yes, but a few degrees here or there is acceptable

    Votes: 96 36.8%
  • No, never noticed any issues

    Votes: 13 5.0%

  • Total voters
    261
I live in a place with thermostatically controlled heating and cooling; I assume most here also do.

Thermostatic cooling is barely present in Europe - so far I have not seen it in any private home apart from a presentation tour through a skyscraper full of valeted flats that appeared to be more hotel than home.
 
This is exactly rght. The temp you use, within limits, isn't so important if you compensate by altering your development times. Higher temps require shorter times. Most developers are designed to perform their best between 65 and 75f. . . . .
"Within limits" is important. Superadditivity (the effect of two or more developing agents combined) may vary, leading to more or less speed, contrast and grain, if you go too far outside those limits. In reality, you can often go quite a lot hotter with modern films (old ones softened and/or reticulated) but not a lot colder.

Cheers,

R.
 
Thermostatic cooling is barely present in Europe - so far I have not seen it in any private home apart from a presentation tour through a skyscraper full of valeted flats that appeared to be more hotel than home.
Air conditioning surely qualifies? But I agree it's far rarer in Europe than in the USA.

Cheers,

R.
 
Can we leave physical chemistry and get back to practical chemistry? My tap water temperature varies from about 50 degrees F in winter to about 72 degrees F in summer. Having just finished developing some vacation photos in D76 1:1, I had to cool the solution to 68 degrees F to keep the same times as I use during the rest of the year. This is why I have a thermometer. It takes an extra couple of minutes but the results do seem reproducible.
 
The rule of thumb that I learned (an approximation of the Arrhenius equation near room temperature) is that reaction rates double for a 10 deg C increase in temperature. So if you develop at 70 deg F instead of at 68 deg F, you'll see about a 10% increase in density.
 
I grew up in a home without air conditioning. When hot in summertime
I waited until the cool of the evening, or developed in the early morning.

Our freezer had just the two ice cube trays it came with.
Those precious ice cubes were reserved for cold drinks!

Chris
 
Hi,

A water bath for the tanks was what I used, meaning the kitchen sink full of water and controlled with ice or hot water and the developing tanks sitting in it: I was doing slide film so no prints were involved.

Regards, David
 
Temperature is critical, but the question is really framed incorrectly. What I mean by "critical" is that it is a variable that cannot, cannot, be ignored if you want consistent results. This is also true if you are cooking food, by the way. It is THE variable. But more important is the way you control it. Luckily, in the range that we care about the most the relationship between time and temperature is pretty linear. Years ago, Zone VI made a timer with a temperature probe that would shorten or lengthen its "seconds" depending on what happened to your water temp. It was a nifty gadget because you could set it up to account for temperature drift during a developing or printing session. Absent that, a good set of tables, or at least test notes, is vital.

As others have mentioned: the linearity of the time/temperature relationship breaks down when the developer is too hot (you can melt the emulsion -- which is just refined gelatin after all, or have a development time so short that development is uneven because the developer never gets through the emulsion to reach the silver salts it is supposed to "develop"), or if there is too much temerature difference between or among your baths (emulsion can crack or reticulate). I know this because along the way I have probably personally made every dumb mistake that can be made in the film development process. After years, the "smart" part of your brain kicks in and you ask yourself why you would ever allow unintended variables in your process . . . it would be like cooking pancakes with a different heat level every time. Why make things so complicated?

"Keep It Simple, Stupid" is what I say when I look in the mirror.
 
my tap water is 73. I can develop film in half the time that it took in Wisconsin, where my tap water was 65. I don,t notice any difference in the sheets of 4x5 film that i develop. YMMV

Nik
 
A lot of variables with photography, that makes the medium interesting to deliver the message. The trick is to establish consistency with the many variables of photography to achieve consistent results.

Temperature is one of the variables. Try to use your solutions at 68 degrees farenheit unless the recipe, like color film developing, calls for something different.

No consistency, then it gets hard, impossible, to figure out the "why" things turn out the way they do.
 
Temperature is a fundamental factor in chemical reactions like those involved in film development.
I always check solutions temperature before starting, but I don't try to control it, I simply adjust the times to the "natural" temperature of things in my lab.
 
Same here - I process at ambient temperature and adjust the dilution and time to match. I usually aim for about 8 to 10 minutes to keep the development even.

In August, I can not get the room temperature below 26c even with a 10kw AC plant running at maximum. To add to the fun, the water pipes run up the outside of the building, giving a blast of 60c *cold* water if you are not careful.

In fact I was able to process my last batch of colour film at ambient temperature (Tetenal kit us d at 30c), just by turning off the AC for an hour...
 
hi, i only develop in room temperature water and i live in the tropics, the water here range from 28.5 to 31C. as a general rule of thumb, i halve the time for 20c development as a starting point. i have not had issues with developing at 30c, except for pqdeveloper where i actually experienced reticulation, which in a way makes the textures interesting, a couple of observations (after developing around 300 - 500 rolls a year for the past few years):

* grains are generally larger at 30c than at 20c
* dev time is generally halved, for normal dev as well as stand development.
* developers used include d76, rodinal and currently xtol.

raytoei
 
If your water temp varies where you are you learn ways to heat/cool it at the start of development. I consider it the starting point but also have to factor in Dilution of developer. For a short time there may be a noticeable difference between 5 mins vs 6 mins at a standard solution. However as we dilute our developer and allow for time as a compensating development process time and temp become less relative (within reason) . Size of film may also impact your processing decisions, 4x5 or 6x9 has less grain issues than the same image shot on 35mm. I find I like 70 degrees and will usually use the manufacturers time without factoring , but I also know my shutters have variability, the way I metered the scene may not be consistent, and ultimately the SBR of the image will have more impact than a couple of degrees. You can go crazy trying to perfect this stuff, but what we strive for is an anticipated predictability.
 
...how important temperature is in B&W developing?
Does everyone measure the temperature for B&W developing?
Has anyone noticed any issues with hotter/colder temperatures?
Do any film/developer combinations need precise measurement?

How important temperature is in B&W developing?
Really important.
Does everyone measure the temperature for B&W developing?
Most photographers. A requirement for best development, and for best wet printing too.
Has anyone noticed any issues with hotter/colder temperatures?
Of course. Most people. I have.
Do any film/developer combinations need precise measurement?
Most of them.

I can't remember one single time my room or water temperature was exactly what I needed... Never in more than 20 years. Developing without a thermometer sounds crazy to me...
But it's easy to do it well: I don't presoak, and just as I pour developer inside the tank and do the first invertions, I place the tank inside a big bowl with water (4-5 liters) at the right temperature (same developer temperature). Depending on weather, I keep at hand a glass with a few ice cubes, or a mug with very hot water...
In the agitation rests, every minute or two I put the thermometer inside the center of the bowl's water, and check... As soon as there's a small change in temperature (less than half a degree), I add a small amount of ice or hot water, stir, and see how precise temperature returns. Fixing and washing are close too.
Cheers,
Juan
 
It is paramount in achieving consistent results, at least with all conventional developers. If you vary the temperaure then time should be altered to compensate accordingly.
 
I assume we are talking about B&W. With color film, you'd better stick to the recommended temperatures or you will get color shifts besides other unpleasant results.

For B&W film temperature is important, the reduction reaction of silver halides to metallic silver follows Arrhenius law. But you do not need to stick to 68 F or 20 C; these numbers do not have the magical properties of the numbers 13 or 7.

If you correct your developing time according to the manufacturer's recommendation, you will also get consistency, at least for a few degrees over or below the sacred 20 C.

With temperatures from 18 to 25 C in the developer, the time correction indicated by manufacturers works reasonably well for me. I have been developing my B&W for about 50 years, all types of film, mostly classic emulsions; in Rodinal, D-76, ID-11, Tmax, DDX and Beutler developers.

Over 25 C it may get hairy with some emulsions; below 18 C it gets boring. I remember TMax being recommended at 24 C, for instance. More than 5 C changes between baths are risky.

With most developers and 100 ISO film, time correction for temperature difference to 20 C, for a few degrees each side, is in the order of one minute for each degree centgrade. For instance at 22 C give it 2 minutes less. This is a rough guide; do follow the manufacturer's graph or correction table.

Ice or hot water are useful to achieve initial temperature; afterwards it is best to keep the tank in a water bath at constant temperature. BTW, I use analytical chemistry thermometers, standard issue. Kitchen thermometers may easily have more than 1 C error.
 
I'm relatively new to developing at home, and film in general to be honest, but I've taken a fairly simple approach to developing; I fill a jug of water and keep subtracting and adding water until it reads 20C on the thermometer. I do this up to 3 times until all my jugs of chemicals are full.
I then process the film using these solutions, not monitoring the temperature through the process. If there's a couple of degrees loss in the developer, my simple mind suggests that the same loss will be made in the stop and fixer, so I feel the total temperature is consistent across the process.
I save 1-2 litres of water at the same temperature and use this for an initial wash, then wash for 5 mins from the taps, adjusting the hot and cold to get it as close to 20C as possible.
 
Hi,
I just do Stand Development now, so take the water temp at the start -about 20 degrees- and then let the film sit there for an hour and a half with one gentle vertical rotation in the middle. Per 35 mm film- 300ml water, 3ml Rodinal seems to work OK. I'm no expert, but I love the slowness of Stand Developing.
 
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