How Critical is Fixer Temperature?

[Peter Lewin]

While developer activity is temperature dependent, how important is fixer temperature? Since I always make up working solutions of developer and stop bath at the beginning of a printing session, I have good control over their temperatures, but since I often re-use fixer from a storage container in my unfinished basement darkroom, it is at ambient temperature, which tends to be below 68F. Since I just finished a printing session, I was curious. (I have prints made over a 40-year period, and have not had any staining, so in all likelihood I can empirically answer my own question with a "not much" but was interested in the correct answer from someone who knows.)

[Vaughn]

Dang it...I was about to answer, but you tossed in that last bit about wanting a correct answer from someone who knows...

[IanG]

Very for film processing, variations in temperature can cause excessive graininess with some film, others may be fine.

When I shoot in Turkey/Greece I find it easy keep my process within+/- 0.2ºC by working at the ambient water temperature (it takes no effort), when in the UK it's harder but does mean consistent high quality results.

Ian

[Kevin Crisp]

It needs to be in the ballpark when developing film, otherwise you can get reticulation of the emulsion from a rapid temperature change. A few degrees isn't going to do it. And reticulating paper isn't easy.

Like so many chemical reactions, I am sure warmer means a more rapid reaction, but I have never heard a suggestion that times be changed for paper to compensate for cooler fixer. I think with certain hard to clear emulsions you might notice it taking longer on film.

[Michael E]

Chemical reactions are slower at cooler temperatures. I once read that fixer becomes pretty much useless below 16° C/61° F. Unfortunately, I can't recall when or where I read that. Maybe someone "who knows" can comment :-)

Michael

[Kevin Crisp]

If you look at publications such as Ilford's blurb on their rapid fix, it gives a 40 degree swing on acceptable temperatures. With no time adjustments. The lower end is around 60F.

[LabRat]

Kodak had mentioned in their photoguides long ago to keep all solutions within a +/- 2 deg range...

Steve K

[Luis-F-S]

Kodak had mentioned in their photoguides long ago to keep all solutions within a +/- 2 deg range...

Steve K

+1!! I try to keep them pretty much at the same temp. Reticulation is not pretty!

[IanG]

Kodak had mentioned in their photoguides long ago to keep all solutions within a +/- 2 deg range...

Steve K

For ºF +/- 2º however for ºC +/- 1 is better and that includes the stop-bath and wash.

Ian

[paulr]

Very for film processing, variations in temperature can cause excessive graininess with some film, others may be fine.

This is my impression as well. When I first started processing film, I noticed a lot of variation in grain from one batch to the next. I had only been paying attention to developer temperature. From that point on I used water baths to get all the chems to within 1° and never had the problem again. This is hardly a scientific test, but suggests that at least in some circumstances temp variations can cause problems.