Film processing temperature - what is the difference?

[marcello.brussard]

Sometimes I like to experiment. Saturday I wanted to test a russian rangefinder (please do not laugh) I had just cleaned/tuned and, at evening, went to a nightime flea market near Rome. I took a roll of HP5 and pushed it at 1600.

Sunday I discovered that I had only some ilfosol left in my cupboard, but even knowing it is not exactly the best for pushed film, I proceded anyway. Yesterday it was so hot in Rome that tap water came out at 30 Celsius and I decided to push the developing temperature to 24 C instead of my usual 20.

The developed film seems to have a bigger grain and the grey tones have a better balance than what I was expecting.

Does the developing temperature has influence on grain and tones rendition? hat are your experience?

Ciao,
Marcello

 

[JHannon]

Hello! sometimes a sudden change in temperature when moving from one solution to another can cause a swelling or wrinkling of the emulsion called reticulation. It makes the grain clump together and appear larger.

I usually try to keep the temperatures as close as possible from the developer etc.

 

[Ole]

Increasing the temperature will increase the activity of the developer. It will also soften the emulsion a bit more. Both these factors will contribute to slightly coarser grain.

Pushing HP5 in Ilfosol S will also give coarse grain...

Most of my MF negatives are FP4, developed in Ilfosol S at 24°C. A beautiful combination...