Home B&W film development, pre soak or not?

Messages
1,691
Name
Mark
Edit My Images
No
So I've been home developing B&W film for about 8 months and some films I pre-soak and others I don't.

And I'm not entirely sure why [emoji38]

I'll soak Fomapan 120 but not bother with Ilford films.

What are the benefits, if any, of pre-soaking? And is it only worth doing on certain films?

Cheers.
Mark.
 
I only pre-soak Fomapan film when using replenished Xtol as a re-usable developer, and that's because of the way it turns the developer green. I haven't pre-soaked when using a one-shot developer. I don't pre-soak any other films.
 
1. I've never pre soaked, but soon will because
2. A new developing tank mandates it in the instructions.

In favour:
Warms film and tank to correct temperature if required.
Can dissolve anti haltion etc as in post 2 and 4
Can help by wetting film and prevent air bubbles

Against
Slightly more dilute developer, as water will aleady be in the emulsion.

It might be interesting to know why at least one tank manufacturer mandates it.
 
I've done both, prewashed and not pre-washed and do prefer ( especially with fomapan ) to have most of the anti halation removed prior to developing (not that it causes any irregularities to the development if not done)

Depending where you are developing and what the ambient temperature is ( particularly in the depths of winter) a prewash can be a huge advantage e in bringing the tank to dev temperature .

I don't think pre-wash is an absolute necesitty but I personally prefer to add the additional stage of 5 mins or so to my film processing.
 
Since when has a Yorkshireman ever stuck to rules??:exit:

In this case, with a new tank and different method of loading, I'd prefer to reduce the variables,I can't see any compelling reason not to presoak, and it will let me see exactly how quickly a full tank fills and empties.
 
It would " bother" me that a tank design would require pre-soaking to be able to develop evenly, or to reduce the risk of bubbles. This would never be a problem in a well designed tank.
Pre soaking to remove antihalation dye, is a cosmetic issue, and never actually affect development.
Pre-soaking to bring the tank up to temperature, introduces a a problem of how to know when the developer permeates the emulsion sufficiently to start working.
It also tends to dilute the developer, both changes require the development time to be altered to compensate.
If the developer is to be used a number of times this dilution effect can be considerable.

A better technique is to use a preheated (temperature controlled) water bath to pre-warm the tank before filling with developer.
In cold, or very, hot rooms It is best to keep every thing in the water bath in their own containers including the tank, developer, stop bath, and fixer.
A tank full of developer can lose several degrees during development, which will vary as to the ambient temperature. for year round consistent results a water bath is highly recommended.
Everything else being equal a prewash is un necessary.

In the days of Glass plates many were coated on the back with a thick semi solvent layer of antihalation material. Some were difficult to remove, but were designed to be soluble in an alkali developer. This often resulted in an argument, like the present one, as to whether pre-soaking was necessary or not.

Bubbles are usually an issue involving agitation and how it is performed. I was always taught to bang the bottom of the tank on the bench to dislodge any bubbles after each agitation cycle.
Bubbles trapped between layers of emulsion can be impossible to remove and are usually a design issue. involving the tank and the film packed too closely to each other or the sides of the tank or septums.
 
Last edited:
Back
Top