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Peter Lewin
2-Jun-2015, 11:21
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
2-Jun-2015, 11:33
Dang it...I was about to answer, but you tossed in that last bit about wanting a correct answer from someone who knows...:cool:

IanG
2-Jun-2015, 11:34
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
2-Jun-2015, 11:50
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
2-Jun-2015, 15:02
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
2-Jun-2015, 15:17
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
2-Jun-2015, 17:28
Kodak had mentioned in their photoguides long ago to keep all solutions within a +/- 2 deg range...

Steve K

Luis-F-S
2-Jun-2015, 18:49
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
4-Jun-2015, 00:56
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
4-Jun-2015, 07:07
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.

Jim Noel
4-Jun-2015, 09:31
A good example of reticulation is on page 178 of "Advanced Photography - Methods and Conclusions", by Andreas Feininger.

True reticulation seems nearly impossible with today's pre-hardened films. What many today call reticulation is really grain clumping and it is easily caused by changes in temperature from solution to solution. With older non-hardened films the gelatin would actually separate into small segments creating a pattern not unlike miniature crazed tile. Sometimes photographers would intentionally reticulate films for effect. With today's films I have intentionally injected a temperature difference of 20+ deg F in an unsuccessful effort to cause reticulation. I have attempted this by increasing the stop temp, and by having the developer hotter - no luck.

IanG
15-Jun-2015, 01:53
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.

It's not strictly an increase in the grain in the film it's the apparent graininess in the print or scan and that's affected my surface artefacts of the emulsion and gelatin super-coat. It's called micro-reticulation or incipient reticulation and caused by stressing the emulsion surface by temperature changes. It was causing Kodak major problems when the first colour digital minilabs came into use because scanning made their films look quite grainy. It also affects glossy prints if they go from a warm solution to a cold one, you get a dulling of the gloss, often patchily, this was another problem for Kodak where prints went from 38ºC to a tap water wash or stabiliser in some machines.

In recent years most films have greatly improved hardening and is why Kodak state their films have been improved for scanning.

Our problem is while most films are now well hardened a few aren't and so it's wise to routinely maintain quite strict temperature control across the while processing cycle including washing.

These surface artefacts were known about nearly 90 years ago and there's a précis of an article in the 1927 British Journal Photographic Annual on wet mounting negatives emulsion to glass to get the highest possible results, something Ctein does and is done for highest possible results when scanning.

Ian

Gary Beasley
15-Jun-2015, 03:54
Since fixer works to completion and we strive for double the clearing time temperature is rendered a moot point in a reasonable range. Emulsion stress as talked about earlier is the only problem left, though there may be minor problems with diffusion rates for washing out the fixer if the rinse water is too cold.