Why Presoak?

[Mark Stahlke]

I've been shooting Ilford films - Delta 100, FP4+, HP5+ and processing them in Ilford DD-X. I've never done a presoak step when developing these films because Ilfrord recommends against it. They claim it can cause uneven development. I process 4x5 in a Combiplan tank and 8x10 in trays and I haven't seen any development problems with my negatives but I'm curious.

What is the purpose of soaking film in water prior to development? Why does Ilford suggest this could cause uneven development?

Thanks,
Mark

[Pawlowski6132]

I've been shooting Ilford films - Delta 100, FP4+, HP5+ and processing them in Ilford DD-X. I've never done a presoak step when developing these films because Ilfrord recommends against it. They claim it can cause uneven development. I process 4x5 in a Combiplan tank and 8x10 in trays and I haven't seen any development problems with my negatives but I'm curious.

What is the purpose of soaking film in water prior to development? Why does Ilford suggest this could cause uneven development?

Thanks,
Mark

Ironically, I presoak for a more even development.

[bobwysiwyg]

Likewise. I've read enough threads here on the pre-soak vs. not to come to the conclusion that it matters little either way, but it was the way I was taught longer ago than I care to think about. It's a bit like starting a "which oil is better?" on a motorcycle forum.

[windpointphoto]

How about just trying both methods, see for yourself if there's any difference, and then you'll know. Make some exposures of different scenes, tones etc.

[Peter De Smidt]

Ilford puts wetting agents into the emulsion. A pre rinse can wash those out. I don't know how much difference that can make, but a pre-rinse is an extra and unnecessary step with Ilford BW films.

[Merg Ross]

For tray development of sheet film I have always used a presoak, regardless of film manufacturer; this includes the Ilford films that you mention. A presoak allows films to be placed in the tray very quickly, eliminating the chance that they might stick together. This assumes a time and temperature development procedure as opposed to developing by inspection. I most often develop twelve sheets at a time. In practice, a presoak increases development time slightly, although you will find comments to the contrary. For tank development such, as you mention, I see no advantage to a presoak.

Edit: Perhaps there is an advantage in that I have never had the problem of uneven development.

[Ed Richards]

I process Tmax in a Jobo Expert Drum. Kodak does not recommend a presoak, so I did not do it for the first few months. I saw occasional streaks and uneven development in clear skies. I started presoaking for 5 minutes and have not had the problem since. No other changes.

[Gem Singer]

What Merg said.

(I only use Ilford HP-5+ film).

[Ken Lee]

What Gem said.

[D. Bryant]

For tray development of sheet film I have always used a presoak, regardless of film manufacturer; this includes the Ilford films that you mention. A presoak allows films to be placed in the tray very quickly, eliminating the chance that they might stick together. This assumes a time and temperature development procedure as opposed to developing by inspection. I most often develop twelve sheets at a time. In practice, a presoak increases development time slightly, although you will find comments to the contrary. For tank development such, as you mention, I see no advantage to a presoak.

Edit: Perhaps there is an advantage in that I have never had the problem of uneven development.

+1!

What Merg said.

Film processed in BTZS tubes with pyro need a presoak. Ilford film never seemed to care.

Don Bryant