Film prewet, how much time?

[Dave west]

I have several loads of T-max 100 4x5 to develop. What is the max time to let it soak in water for a prewet? It seem's I'm leaving in the water longer and longer. Is this OK! Any help please, Dave

[Brian Ellis]

You don't need to presoak T Max films. Presoaking apparently used to be helpful in promoting even development back in the bad old days. With today's modern films I don't think it's necessary. In fact I seem to recall that Ilford specifically recommends against presoaking at least some of their films. I've done tests of presoak vs no presoak with tray development and with BTZS tubes using T Max 100 film and Ilford HP5+ film and using pyro and D76 developers. Presoaking didn't do anything with any combination of film, developer, and method of development. Others may have a different opinion but I think you're wasting your time with the presoak of T Max film.

[Dave west]

Thanks ..............I just use it to bring the film to the same temp. as the D-76, what Irealy need to know is" does soaking in water itself harm film for an extended amount of time". Maybe your right and I should stop it, bad habit. Dave

[Gem Singer]

Dave,

If you are using tray development, pre-soaking for a minute, or so, will help to prevent the films from adhering to one and other. Otherwise, no need to use a pre-soak. The film and developer will both be at the ambient temperature of your darkroom with, and without pre-soaking. Soaking in water for an extended amount of time probably won't cause harm to the film, as long as the water is not too warm. But, it won't do it any good, either.

[Andre Noble]

I always pre-soak for 5 minutes. When I recently neglected to do so and on a 120 roll film batch, sure enough I got blotches on my negs due to air bells.

[Ralph Barker]

How are you processing, Dave? Trays? Jobo drum? (I believe presoak is recommended for Jobo.) Unless your environment is extreme, I'm not sure that temperature equalization is really necessary.

While I haven't done any tests with extended presoaking, I'd guess that anything within reason isn't going to be an issue at normal developing temps, as long as due care is given to the potential resulting softness of the emulsion. (Some stand development techniques have the film immersed for hours, for example.)

[Steve Sherman]

When posed this question I make the following analogy.

When a sponge is dry and you try to mop up a spill it doesn't like to take the liquid very easily or uniformly. Uniformly being the operative word, film and sponge in this case are interchangable.
My 2c

[Dave west]

Well I see others think the same as I .......Thanks! it's good to know I have'nt totaly lost my mind. I hate to admit this in public but I still use an old square black daylight tank. It seems OK for the way I agitate it.....I hate to change. My pre-soak is for at least 5 min. Dave

[mark blackman]

Jobo don't recommend a pre-soak for E6 film, but they do for B&W. Ilford's advice for B&W processing is not to use a pre-soak!. So I compromise by doing a 5 minute pre-heat (run the tank for 5 mins without water), to bring the film & tank to the same temperature as the developer.

[Witold Grabiec]

I pre-wet more than pre-soak. They sit in the water for some 20 seconds with minor agitation. I try to drain the negs as best I can, before they get introduced to a developer. It makes me happy.

[Nature Photo]

I use a CombiPlan tank and prewet (not soak!) films mainly to reduce the chance of air bubbles forming during development. As such, I drain the water after 10-20 s (just like the previous poster). This 'prevention of bubbles' is more of a belief than a fact, as I don't have proof that it's necessary.

The prewetting also eliminates the indigo/grey color so that the developer stays clear (I reuse it).