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David Aimone
15-Jun-2011, 09:43
Searched for this but couldn't find a good answer. When developing B&W film, I'm VERY careful about the temperature of my developer (and the presoaking water), but not very picky with the stages after that---stop, fixer, etc.

This time of the year those chemicals are in the mid 60F temperature range. In the winter, they are a bit colder.

How important is temperature regulation for the steps after the developer. Am I likely getting results that are varying noticeably from different temperatures?

Sirius Glass
15-Jun-2011, 10:06
Big changes in temperature can cause reticulation of the gelaten. See reference: http://www.apug.org/forums/forum37/80193-grain-micro-reticulation-b-w-fim-process-temperature-deviations.html

Steve

Bruce Watson
15-Jun-2011, 10:07
How important is temperature regulation for the steps after the developer? Am I likely getting results that are varying noticeably from different temperatures?

Best practice is to keep all temperatures the same and constant through the process. But you knew that already.

Changing developer temperature can result in visible changes to the image. Changing the temperature of the steps that follow typically don't make any kind of visible change (assuming you aren't shocking the emulsion into reticulation). But you do want to make sure that the fixer and final rinse are actually doing their jobs. If they aren't, you'll see changes years from now, and they won't likely be recoverable.

The only way to know for sure is to test for residual silver (to see if you are fixing sufficiently), and for residual hypo (to see if you are washing sufficiently).

IanG
15-Jun-2011, 10:12
It pays to be careful with temperature variations. Some films are fine but others will show problems with even quite moderate changes.

Living most of the time in Turkey over the past few years I process at 27°C with less than 0.5°C deviation +/- over the complete cycle, actually quite easy to do as that's the tap water temperature most of the Spring through to about November. There's no differences in terms of quality between negs processed at 27°C and those in the winter or UK at 20°C

Ian

Gem Singer
15-Jun-2011, 10:41
From experience, I have noticed that the agitation pattern and the frequency of agitation has a greater effect on the the negative during development than slight variations in temperature.

I begin my film processing procedure by tempering the solutions to 70F. During the procedure there usually is a slight change in temperature due to the ambient temperature in my darkroom. As long as the temperature increase, or decrease, is not excessive, I am not concerned with over development, under development, or reticulation.

I wash film at the ambient temperature of my tap water, which can range from 65F in the winter to 85F in the summer.

Ilford hardens the gelatin in their films, and they warn not to exceed 86F. That seems to be the critical temperature where the gelatin begins to soften.

cyrus
15-Jun-2011, 11:45
Eh, according to Ctein there is no basis in the idea that all the chemicals must be kept at the same temp. In my experience temp is only important in the development stage. Naturally this doesnt mean that the fix or stop can be boiling hot or anything like that but 60-70 is probably fine.

So how important is temp in development? Well, I've never tested it but the time/temp graphs shown with most films have a pretty steep curve, and so a slight change in temp seems to correspond to a significant difference in time. However having said that, I am one of those poeple who only checks the temp of the developer initially, and not for the whole lenght of development time (which in my case is rarely over 10 min.)

David Aimone
15-Jun-2011, 11:49
In my darkroom, bottled chemical temps range from 60F-70F winter to summer, and tap water 45F-70F over the same period. So the only thing outside the 60-70F range is the final rinse water.

I'm probably good to go then...

IanG
15-Jun-2011, 12:04
If you're not shooting 35mm or 120 Tmax 400 or Neopan 400, or any Adox/EFKE films yes :D

Those are the films which will suffer most from micro reticulation with temperature variations, this affects the apparent graininess of prints.

Ian