Tuesday, June 21, 2011

Pre-wash, another myth exploded?

Back when I was young I learned how to develop films and pictures in what was a traditional photo club. I learned the tricks of the trade from people who learned their way around a darkroom in the 1930's  (still has negatives from railwayman, music conductor, tetotaller spokesman and amateur photographer Alfred, my first great darkroom buddy).

I was told how to do things and what not to do, and after a few stupid mistakes, what I was told is still ingrained......

There was never anyone mentioning pre-wetting, pre-wash or anything remotely like that.  Mind you these oldies where guys that started up with Kodak cameras where you could inscribe picture data on the back of the film, via an opening in the back and a metal pen to pierce the backing paper slightly.  They upgraded to pack-film or glass plate cameras, and developed by hand, in red light, after desentizising the film (after the general advent of panchromatic film)  Maybe they where pre-washing  glass plates - it was never mentioned, these guys where happy over the transition to 120 (or even 620) film, some had moved on to 135 film and leica-format cameras, Alfred never did, he was perfectly happy with his quality german folder, 6x6 with something as rare as a 75mm f:2,8 lens...

Moving on into the small format world I had to rely on books, and Hans Windisch' famous "neue Fotoschule" was the foundation. Recently I found a like new copy of that book and have read it several times. hans was famous for his fine-grain developers, his W665 and W22 still lives on to this day.  A few days back I went through this book another time just to check the facts. Absolutely NO mention of pre-wash techniques, and Hans was very particular in his darkroom, a great photographer too, who made several landmark pictures after WW2.....

OK the check this further I went to my tome on photo techniques : Wissenschaftliche und Angewandte Photographie" :

Im posting the forewords here for interested parties :

As one can see this is in german, so to have this properly translated I contacted Bernd, who is a german, with perfect command of the english language, to get it right.

Below is what they have to say about this topic in this german standard tome, followed by Bernd's translation.

Bernd :

The kinetics of developement in praxis

a) Pre-wash and its influence. In some cases the light sensitive
material is pre-washed in water in order to avoid adherence of
air bubbles during the development and the resulting flaws.

Bernd :


This procedure originates from times when no effective wetting agents
were available. Pre-washing only yields a completely even development
when the whole gelatine layer is completely soaked. Otherwise there may
be different levels of developer concentration throughout the layer.
Additionally partially soaked gelatine layers offer increased adherence
for air bubbles and dust or dirt particles. Also left over bromide salts
from the manufacturing process are washed out. This can enhance
development of less exposed areas in developers not containing potassium
bromide. In highly concentrated developers pre-washing increases the
initial development speed because of increased diffusion speed. In
diluted developers pre-washing may cause a further dilution resulting in
longer development times. Hardening of the layer only delays development
in case on intermediate drying. Pre-washing in desensitising solutions
have the same effect as pre-washing in water in terms of wetting the

Today pre-washing is hardly done anymore. Because of before mentioned
reason one would strongly advise against it. Pre-washing can be useful
to remove anti-halation layers on sheet/plate film and to protect the
developer from polution. To achieve this the sheets/plates are placed in
water until thoroughly soaked and the anti-halation is wiped of with a
sponge and rinsed before development.

In the back of the book is a section on errors and failuers and how to correct :

Bernd : 

1. Irregular, light spots

Cause: Emulsion layer touched with fingertips which always
leaves oil on the layer. These oil stains repel the developer.
These spots can also be caused by pre-washing in too cold water.

How to avoid: Never touch the emulsion with your fingers. Only
handle film on the edges. Don't pre-wash as this may influence
the developer concentration.

How to fix: No fix possible.


My take on that : modern emolutions don't NEED pre-wash. On the contrary pre-wash may couse more and other problems than one tries to solve, and better solutions to the original problem is easily at hand.

I have said and stand by : this is an outdated technique, something someone has gleaned from an old book without properly understanding what they have read, and why it was done back in the day.

To try to impress others, it seems to me this is a case of the blind leading the blind or The emperors new clothes.

If you want reliable, prdictable & repeatable results you need not do this.

If it makes you happy, knock yourself out.


Dan what was it you didn't understand from the above?

The book cited was an update on a german standard used at german universities both pre and post WW2, for students of  photo technology....

You seem to offer only individual anecdotes...

1 comment:

  1. Pre-wash works exceptionally well for various uses. For hand-tank processed C-41 it markedly improves processing quality and reliability, and also gives more time to get your initial agitation going. There are problems that can occur like uneven heat diffusion and other things.