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 keep my temperature between 18-21°C and in summer in the UK that's what tap water comes out at!
I think more importantly keeping other solutions ±1°C especially with softer emulsions like EFKE etc. Hardened gelatin like the ones Kodak use in TMax can with stand 25-30°C —not that I ever process them at those temps.
That said I like high dilution long developing times and don't use developing times below 5 mins for consistency so I keep mine at 20°C.
 
20C and that's all. It's pretty easy to process at 20C even if the outside temperature is higher, there is always one way to get the working developing solution being at 20C, for instance you can dilute the stock solution with water stocked in the fridge door etc.

Yet don't get paranoid : the developing times aren't long enough so that the temperature inside the tank will increase much if you start at a real 20C.

Stop, fixing, rinsing, wetting baths are less critical as for the temperature.
 
The good old Arrhenius law me thinks ... k = A*exp(-Ea/R*t) ... :D

Gabor, have you ever researched on whether film development reaction is a first order reaction with respect to the developer? I suspect HC-110 follows first order rate law because of how the development time and concentration of developer is related.
 
I keep the temperature consistent, but at 25C - my tap water is 29C - its just easier to maintain between consecutive tanks
 
I work at the ambient temperature ... one of the few plus points of a temperate maritime climate and central heating
 
To put it this way. It is as important as the dilution of the developer. Change in either will require a change in timing. Warmer developement (than recommended by film and/or developer manufacturer) will often lead to fatter grain. Temperature can also be used to adjust contrast. So yes, I measure very carefully in order to get the results I want (every time).
 
To put it this way. It is as important as the dilution of the developer. Change in either will require a change in timing.

Concentration (and agitation regime) changes can do a bit more than that - they will affect acutance (which is a effect of local in-emulsion depletion of the developer).

Temperature is merely proportional to timing, at least for times where the time lost over filling and emptying is negligibly small, and as long as you stay below the limits where the gelatin may peel - that is, don't develop at times below two minutes or temperatures above 40°C (not above 25°C for Efke and other unhardened film).
 
Constant temperature is vital for consistent results. My negs became noticeably better when I started to place the tank in a 20C water bath between agitations. That helps to keep the developer temperature changing less than 1C during a typical ten minute developing session.

What comes to stop or fixer temperatures, I don't worry so much.
 
In the summer my tap water is > 25 C, and I used to adjust time using the dev chart. This led to some blocky negatives with little detail. One RFFer cautioned that if you go much under 5 min dev time you can expect reduced quality, and I believe it.

A bag of ice from the corner store is the cheap and easy solution. I just put some ice in a plastic bag, it's easy to keep the temp within one degree of 20.

Randy
 
I immerse my developing tank into a water bath maintained at 20 degrees celcius using ice cubes or cold water from the fridge. It is easier to maintain constant temperature with a bigger volume of water. The water in the water bath is then used for rinsing.
 
I use mostly XTOL 1:1 and just use the times given for different temps in the XTOL pdf. I took the data in there and fit a line to them so I have times for 68-75 F or 80 F (depending on the film) in 1 degree increments. 90% of the time my tap water comes out somewhere in the range - if it doesn't I heat or cool it until it's in that range. The rest of my chems are kept indoors, so they are close enough to those temperatures as well.

So temperature is important, but I've not seen too much of a different if you adjust the times appropriately and you are inside the range of 68-80 F. I've kept pretty meticulous notes on all my film development, with times and temps for each roll, but have never really had a problem with any of them. I will say that even at the hotter temperatures, XTOL 1:1 never really gives you times below 5 mins (I think 7 is about the shortest for my films), so you don't have to worry too much about too short dev times.
 
Consistency and repeatability are more important than the actual temperature.
After beating my brains out trying to maintain the traditional, lower temperature in the Texas Inferno, I caved in and went with ambient temperature in my kitchen, ~75F. I printed out the linked PDF and keep it handy. I put pre-wash water, developer, stop water & fixer in a sink full of water a couple hours before developing begins. When it's time to develop, I look at the temperature, consult the chart and GO! Xtol 1:3 keeps my time above 7 minutes for comfort. Life is much better since I quit fighting tradition.
For the "average start to finish time" folks: My research found that over a ten minute span, the temperature of the developer rose to ambient room temperature in less than 3 minutes. The developer temperature was NOT the average of the start and end temperatures.

http://www.ilfordphoto.com/Webfiles/2006210208211880.pdf

Wayne
 
I mostly use Rodinal. For the normal recipes (between 10 and 20 minutes), just a couple of added degrees will have really strong impact on film sensitivity and grain. So I keep it constant at 20 degrees, either by adding hot water or ice cubes to the water before I start. I agree with Wayne that consistency is even more important - here in California faucet temperate varies throughout the year.

I don't care about temperature when washing or fixing.

For stand development, development temperature matters less.

Roland.
 
Didn't find any threads on this topic, just curious to know how important temperature is in B&W developing? I always used water straight out of the faucet, but I recently measured the temperature and found it was 23 deg C/73.4 deg F (versus the recommended temperature of 20 deg C/68 deg F).

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?

It is really important. For example, if I had the described above situation, and the time of normal development of my film was 10 minutes (for 68deg F) I would keep it in development for 8 minutes insted. That important.
It is easy to control, why cheat on something so simple?
 
Has anyone experienced reticulation in their negs from all that temperature yo-yoing (adding ice when the tempering bath warms up) , stop/fixer/wash at different temperatures - and everything way different from ambient air/water temperature)?
 
Once I took control of my temp, I noticed a big difference. Stay consistent! I really think 2 degrees makes a difference.
 
Has anyone experienced reticulation in their negs from all that temperature yo-yoing (adding ice when the tempering bath warms up) , stop/fixer/wash at different temperatures - and everything way different from ambient air/water temperature)?

Actually, I keep all the solutions in the same bath, and mix the developer with water at the target temperature (I figure the stop and fixer will be "close" by the time I am ready for them). I try to adjust the wash water to be close to that same temp, but in the Summer that is not possible. Have not had issues with reticulation.

Randy
 
Temperature is important in controlling grain and times to me. I used to be very particular about getting it to 21.5 degrees because I almost always push my films an additional 7% regardless of what speed it is shot at and that brings tri-x @ 800 in XTOL 1:1 to a cool 9:30, but lately I've mostly been satisfied with 21-22 degrees. I'll still aim for 21.5 though, especially if I know there's a good shot in the roll.
On the flip side, my friend channels Daido when he's in the darkroom, develops until he feels its about right, agitates erratically and sporadically and otherwise doesn't process in a repeatable way. His work comes out fine though. His only limit is 30 degrees celcius because of reticulation, but when I'm in the darkroom with him he goes by the massive dev chart app on my iPod.

It's a process that would make most film shooters cry.
 
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