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
The water gets pretty warm here in HK so I use ice to lower the developer to 68F. usually the development time is under 10 minutes so the risk of the temp rising in the tank is minimal. If you use a warmer temperature then you need to compensate with shorter development time. There is a chart you can find online but I find that to be a crude estimate. I tend to stick to 68F for consistency.


Same here, it's 24-25 degrees c out of the tap in Bangkok sometimes so I have to use ice chilled water and find a good balance for keeping it just nicely in the 20 degrees c spot for my developing.
 
Didn't find any threads on this topic, just curious to know how important temperature is in B&W developing? QUOTE]



It's only important if consistent results are desired. Inconsistent water temperatures are the easiest way to ruin film development.

Time and temperature are linked. However, the temperature is not fixed on one number. For reasons known only to Kodak and Agfa, all development regimens are based on 68 F / 20 C and variable time for different films.
There are tables available online that converts the time for different temperatures. Ilford had a good one online. I have not looked in ages. I printed it and put it next to my timer.
Is there an app for that? Time/Temperature table app?
So, piece of cake. Get an accurate thermometer and timer and follow the table.
Wayne


Sent from my iPhone using Tapatalk
 
Tap water is usually above 68f even in a Texas winter.
I have a styrofoam box that fits in my kitchen sink. It will hold enough water to use for presoak, stop, and wash. If I have to adjust the temp of the tap water anyway, it is easy enough to get to 68f. I set my developer in a plastic bottle in the water beforehand. My tank will sit in the water during development. I expend the water at the finish, as wash, so I use about 3 gallons total to develop a 4 reel tank.
 
Back in the '70's with Tri-X if you went too fast (too hot) you could cause changes in the look of the grain. I seem to remember something about being able to tweak contrast a bit too, but can't speak about specifics. I also remember hearing about differences in chemical product based upon where it was shipped to be sold. There are large tap water differences around the world that could impact results, but they might have addressed this with changes to the formula.

As mentioned before, yes temperature is very important if you want consistent results. It's all part of the chemical equations for film and paper. Sort of like using a CPU with a bad math-co-processor..........

B2 (;->
 
Reaction rate dependence on temperature is represented by the Arhennius equation. But the general rule of thumb is that reaction rates double for each 10 deg C increase in temperature. So, yes, temperature is important, but +/- a deg C will make little difference.
 
My darkroom is in the basement. Yearly temperature runs from about 18 to 21. rarely outside that range. I keep water at room temperature, measure, and use the Ilford chart to tweak developing time. I don't own a densitometer.
 
As long as your temperature ranges are within reason, if you develop consistently, you should be OK. Granted, I have never made any tests to see what temp variables would do to my negs, but I keep a pretty good written record and have that to fall back on.

Obviously, you have to have the temps within the film's tolerance. You couldn't use ice water or steaming hot water, so temperature is certainly important. Again, if you consistently develop for what you got out of the faucet, no problems.

Consistency and keeping some sort of records (for when you may have over exposed a roll, used out dated film, etc) are the keys. For sure you can get too much grain from too much heat, but how much is too much? That's why writing down stuff helps a lot.

Having said all that, I always keep the developer and fixer within 1 or 2 degrees of where it is supposed to be. Stop bath I quit using, and just go w/ a reasonable temp out of the faucet. Same for the 30 minute wash. On the stop bath, I actually did test with stop bath and with plain tap water and saw no difference. The fixer goes off quicker though.
 
Nothing to worry about so long as you do not mind finding proper contrast by experiment for every roll!!.

Get it right to begin with and it all works.

I have a darkroom book Ilford gave out at some seminar 35 years ago. Time adjustments for deviating from 68 and it works too.
 
The only liquids I use for developing and washing a roll of 35mm film are a tiny bottle of Rodinal, a 500ml bottle of working rapid fixer, and a gallon jug of distilled water. (I use the Ilford film washing method.) In the heating months all the liquids are stored in the closet containing the water heater which stays at about 68º. In the cooling months they are on the floor against the north wall of my workroom where they stay at about 72º. I measure the temperature of the working Rodinal developer (1:50) and look up the required developing time on an old Agfa time and temperature table on the wall. I see no differences between the negatives developed over that temperature range. But I do only use cubic grain films, not tabular grain.
 
Many of us live or work in climates where water temp pushes 80dg f in warm months. A standard rule of thumb in Navy photo labs used to be to subtract 1 min for ever two degrees higher than 68dg for black and white film.
I personally never get close to times of 5 min or less or Temps of more than 75dgs and just seal my film in air tight jars and put it in the bottom of the fridge till cooler times. Within those bounds, my film has been just fine. I've been doing this since 1968 with Tri X and D76 1to1.
 
Nice to see this thread revived. There are two weeks each year when my tap water is exactly 68 degrees. It should be there in another week or two and then again mid to late September. During the hottest part of the summer the tap water gets to around 72 degrees and so I will cool it down to 68 degrees with an ice cube or two for the developer and use it straight out of the tap for rinses. During the rest of the year I have to mix in a bit of hot water to get the developer up to almost 68 degrees and then keep the measuring cup in hot water for a minute or so to get the temp to where I want it. I feel that keeping the developer at 68 all of the time (with some drift due to ambient room temperature) gives the most consistent results. Is this the best way? No, but it works for me.
 
Most of us wouldn't even contemplate varying the dilution or time, without good reason, so why change the temperature? Answer it makes no sense, so get a reliable thermometer and eliminate another variable. Stick to the recipe as with cooking.
 
For me, it depends on the developer, the type of development, and the temp. variance. I suppose it depends on the film too.

For something like stand or semi-stand, I find it doesn't matter. I routinely develop at room temp -- what ever that happens to be -- when doing semi stand. So too with a developer like Diafine (in my experience). These exhaustion type situations.

The rule of thumb I learned is to add 30 sec for every 2 degrees F temp is off. Warmer liquid speeds up the chemical reaction, cooler does the opposite.

I'm pretty loose with everything I do. If I'm w/in 1/2 degree, I just let it rip w/o any adjustments. Same with development concentrations BTW. I just want to be relatively consistent from roll to roll.

An analogy would be exposures, at least for B&W photography. As long as I'm w/in a stop (or two!!) of what a light meter would tell me, I'm good to go.

Sometimes I think people make to big a deal about this stuff. But this is just a hobby for me. Others are different.

In my experience, you really have to go off the rails to screw up development, at least for B&W. My one attempt at color film development was an utter failure, so I know little about that.
 
The majority of the responses to the OP have been on-point. A related question, for any chemists who might be lurking on this thread, is the role of temperature in two-bath developers ... I see that a previous post mentioned stand development, so that made me wonder about two-bath formulas ... Anyone have any dynamics on this method?
 
LOL. You are talking about chemical reactions so temperature is important, just the way it is in baking. For most developers, if you alter the temperature, and unless you also alter other variables (e.g. time, developer dilution, film exposure etc.) you are going to get very different results than you otherwise would. At the extremes, you can melt the emulsion (e.g. developer too hot) or crack/craze the emulsion (too wide a temp swing between baths). Or have no reaction at all (too cold). And, LOL, since I have personally made all these mistakes, I speak from personal experience.

Of course, there is a degree of change -- say within the error of your measuring device -- that won't make a discernible difference. Call it 0.1 degree F.

The most important thing for your own results is consistency. Always use the same thermometer, and try to minimize the variables in your development. Zone VI used to make a probe/timer combination that read the temperatures with a metal rod and then adjusted what a "second" was so that your results would be as consistent as possible.

I have one, but use it more with paper development to account for drift in the temperature of my printing bath over a printing session.

And there are other variables too. Jobo processors had continuous agitation for the film and cut down on development time in their recommendations. The rotating drum spun in a temperature controlled bath. So: Important.
 
[Addendum] I see that I responded to this thread around six years ago. Ha! At least my answers were consistent. I am betting that the OP has developed many, many rolls of film since the original post above.
 
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