Developing Film in Summer

[Masuro]

I shoot Ilford Delta 100 and use Ilfosol-S as my developer. Standard developing temperature is 20 degrees but this is impossible to maintain throughout the developing time because it's hot here. The temperature of the developer is about 21.5 degrees by the time the film is done. I have the time/temperature chart but because the temperature is constantly going up, I'm not sure how accurate it is. With Ilfosol-S, could I start at, say room temperature, and set my timer accordingly? Or would using a higher temperature degrade the quality of the negative?

 

[Jersey Vic]

I can't speak for ilfosol-s but always adjust my developing times to match the temperature of the chemicals and the gallons of water I store in my bathtub. (My wife loves this) I imagine the manufacturers optimal results are achieved at recommended temperatures but I've not noticed enough of a difference to make me change what I'm doing.

 

[Snapshot]

I'm fortunate that my basement usually sits around 68F during the spring, summer and fall. However, I do recall sometime ago that there was some analysis done on time/temperature combinations. The crux of analysis was that temperature doesn't really matter and you won't have degraded film if you use a higher temperature and shorter developing time. You just have to adjust your developing time accordingly.

 

[Alex Hawley]

Ilford has a universal temperature compensation chart. You can download it as a pdf file here.

 

[Masuro]

Thank you. I have that one printed out and in my darkroom for reference. I was just wondering if there is a loss of quality but, as the other two posters have said, there doesn't appear to be any. That will make life a bit easier.

 

[Masuro]

I've just tested room temperature water and found it is 25 degrees. I hope that is lower at night.

 

[PHOTOTONE]

As long as you can control the temperature to be stable for the developer, stop and the start of the fixer, and use hardening fixer, your film should be OK washed in warmer water, than you processed the film in. You can always sit your tank in a deep print developing tray, or dishwasing tray filled with cool water, even with a few ice cubes, to keep the temperature down.

 

[PHOTOTONE]

I should also call your attention to the fact that people were successfully developing film and plates for half a century before good temperature controls were available. And, the emulsions were much easier to damage then.

 

[fschifano]

The key here is to keep the developer temperature stable through the process. You can maintain a stable temperature simply by leaving the tank in a suitably large container of water for the duration, or at least for the time that you're not agitating. Four litres of water is a sufficiently large heat sink and will not radically change temperature in the ten minutes or so that it takes for the development process to complete. Some folks will call me a heretic or worse for saying this, but temperature control for stop and fix is not nearly as critical. These two processes go to completion. Stop is immediate in any case, but fixation takes a little longer at cooler temperatures. Plus or minus 5 deg. F (~3 deg. C? - close enough) isn't going to make one bit of difference. Modern films are sufficiently sturdy to handle this without any problems with reticulation. There's no need for a hardening fixer either, for the same reason. Exceptions? Sure. They tell me Efke films have softer gelatin and need a hardening fixer.

PS: The Ilford temperature compensation chart has good data. You can use it with confidence.

 

[Masuro]

Thank you all for the advice. I tried last night at 22 degrees and it had risen to 'only' 23 degrees by the end of the process. I rinsed the film a little bit early and they seem fine. I might try the sink full of water next time to see if it helps. Thank you for the idea.

 

[Woolliscroft]

I also use a water bath for B&W when it is very hot (or very cold), and always for colour.

David

 

[Rick Jones]

If you use a tempered water bath with a stainless steel tank you can control developer temperatures very tightly. I use a plastic water filled dish pan 12 X 14 by 7" deep which allows me to control the developer temperature +/- .25 degrees. That level of control is not really necessary but the water bath makes it easy. You mention "standard developer temperature". The 20 degree temperature mentioned often by manufacturers is totally arbitrary. There is absolutely nothing magic about 20 degrees. Pick any reasonable temperature and you will be just fine.

 

[Roger Hicks]

You mention "standard developer temperature". The 20 degree temperature mentioned often by manufacturers is totally arbitrary. There is absolutely nothing magic about 20 degrees. Pick any reasonable temperature and you will be just fine.

And indeed 18 degrees C/65 degrees F was the 'standard' quoted in many books up to the 50s.

Cheers,

Roger

 

[nworth]

Fortunately, the tap water you use to dilute the developer is usually a lot cooler than the room temperature. If need be, you can even drop an ice cube or two into it. It usually isn't hard to get the developer to a usable temperature. A usable temperature is anywhere between about 62 and 77F, with some possible slack at each end of the range.

You can correct the development for temperature by changing the development time. There are a lot of charts around to tell you how much. My old Kodak Master Darkroom Dataguide has a calculator which works out a correction of about -6 percent per degree F. Unless the difference between the room temperature and the solution temperature is very great (like 25 degrees F), you can probably get away with measuring the solution temperature just before you start developing and using the time you calculate from that. If the temperature difference is great (> 25 degrees F) and/or the development time is very long (> 25 minutes), you may need to make a correction - perhaps use an effective temperature 1/3 of the way between the solution temperature and the room temperature.