Your Thoughts on Pre Soaking Sheet Film Prior To Development

[Doremus Scudder]

I develop multiple sheets of film at one time in trays. A presoak is necessary to keep them from sticking together. I've found that the one minute presoak that Kodak recommends is too short for some films. One needs to be sure that the emulsion has absorbed as much water as it is going to and is at equilibrium before beginning development or you can get unevenness. I presoak for a minimum of three minutes.

Some say that Ilford films have a surfactant incorporated into the emulsion. I'm not sure if this is true or not, since I've never heard it from a really reliable source. If true, then a presoak would have to be long enough to allow the surfactant to reach some kind of equilibrium too or uneven development would result. Longer might be needed here.

With roll film and tanks where you can pour the developer in quickly, a presoak is unnecessary. If using a tall tank with multiple rolls and long pour times where it would take a significant fraction of the development time to pour in all the developer, I imagine a presoak would be helpful, since it slows down the uptake of the developer somewhat and would compensate for the long pour time.

Best,

Doremus

[Peter Collins]

Chiming in: I use a SP-445 tank and HP5+ (currently, but sometimes Tmax400) and I always pre-soak. Yes, I know Ilford doesn't recommend.

[Vaughn]

I've always pre-soaked...habit and good results is why I continue. I have some 8x10s spinning in a Jobo 3005 as I type. It take 4 seconds for the drum to make one revolution (15rpm), while pouring developer onto dry film seems odd to me, that 4 seconds is not very long.

But no one seems particularily worried that when adding stop bath or fixer, the film is pretty well 'pre-soaked'.

[Mark Sampson]

When I processed 4x5 in trays, I used a presoak so the sheets would not stick together. I added a pinch of Kodalk to the presoak tray- the slight alkalinity eliminated any sticking. That was my practice (for personal work) for many years. When I ran sheet film in the various labs, a presoak was not part of the procedure. Now I use a Nikor tank, and presoak with plain water; since it takes 30sec. to fill the tank, this (I hope) reduces any chance of unevenness.

[Merg Ross]

When I processed 4x5 in trays, I used a presoak so the sheets would not stick together. I added a pinch of Kodalk to the presoak tray- the slight alkalinity eliminated any sticking.

I also use Kodalk (Balanced Alkali) in the presoak tray. Perhaps already mentioned, a presoak is known to prevent air bells.

[Jac@stafford.net]

In my modest experience, pre-soaking film is not necessary unless the manufacturer recommends it - do any recommend it? It would be inadvisable because they cannot know the composition of your water. Preventing air bubbles? Ridiculous.

[Peter De Smidt]

I've never used a pre-soak with black and white film in my Jobo. Ilford, btw., recommended against using a pre-soak, as they had wetting agents in the their film to help with even development. These could be washed out with a pre-soak. That said, decades of photographers have done one or the other with great success, and so it's unlikely to be a big deal.

[hoffy]

Interesting to read that those who pre-soak do it because, "that is how I was taught" and "I've always pre-soaked and never had a problem".

As the first film I ever processed was Ilford and the literature said not to pre-soak, I tend to just follow the instructions (for example, I do pre-soak Foma films, because, well, they recommend it).

Just remember that "because that is the way I have always done it" does not necessarily make it right, but I do suspect that in this example, it doesn't really make much difference.

[Graham Patterson]

Bergger do recommend a 3 minute pre-soak for Panchro 400. They also state that some anti-hallation dye will come out. I am not sure it is _necessary_ for tank development, but it is a blanket recommendation.

[Luis-F-S]

I do 2 one minute presoaks when I develop 810 in tubes or tanks