Both Haist and Mason were published in the mid 70s.
Thank you for posting this - observed facts are always good! And thanks to everyone else who has contributed, I teach B&W photo at basic and intermediate level and have always used the IWT, good to have some more info about it, because I do get asked sometimes by students "does it really work?".
Originally Posted by Fotohuis
we could all post links to some unproved web page, but what does Ilford actually recommend?
You can find Ilford's recommendations on their film fact sheets – e.g. http://www.ilfordphoto.com/Webfiles/...6115141521.pdf
Originally Posted by Ray Heath
See page five under wash
Please note this:
• This paper does not prove that the Ilford washing instruction under all conditions leads to films of archival purity.
The only issue is that there are obviously very early conditions reached, where washing can be stopped, because
subsequent washing is just a waste of water without any decrease of hypo concentration in the film. (A
statement about archival purity would only be possible if the hypo content would have been really determined,
which is beyond my ability).
• This paper does not say, that the Ilford method can just be used as published by Ilford. In my opinion the
instruction is too course and does not consider water volume per film available
These disclaimers are at the top of the PDF file referenced above and located here:
Please note that the first disclaimer is almost exactly what I said above! The author doesn't claim that this method gives archival washing. It does wash, but offers a minimum wash condition that will 'just pass', my words for many conditions, and may not for some.
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Another note on this article.
In part 7, the author assumes that 90% of the chemicals are removed from the fillm in each wash step, but both Haist and Mason use the more widely accpeted figure of 50% and which seems to have some basis considering the diffustion equations they used. Therefore the wash rates are quite different by a considerable margin in the textbooks and in this article.
In addition, the only thing being tested for is residual hypo, but in fact, you are also trying to remove silver complexes, hydroquinone and metol (if that is what your developer contains). No one here has mentioned this yet, so I thought I might just drop this into the mix for you to consider.
FYI, Bill Troop is rather busy but he has sent me a private note with his permission to publish it here. It relates directly to this thread.
This is a direct quote from his e-mail, minus some private chit chat. Since he just got married 2 weeks ago, he is kinda busy.
Ron, there is no 'Ilford' multiple soak wash method. There is a Kodak method, researched by and published by G.I.P. Levinson, one of the most eminent of the scientists at Kodak Harrow, in the 1970s, during a period of water shortages in Britain. This was misread by someone at Ilford and incorporated into Ilford instructions by accident -- minus the obligatory five-minute waiting times. Ilford has unfortunately never corrected its error. Ilford's own leading scientist, L.F.A. Mason, did not fall into this error. I would have thought that would all that was needed to be said about the subject -- ever.
So, here is Bill's personal note to everyone and confirms the data in Mason and points to the errors in the Ilford data.
You can quote me on this!
Ohhh I see... this is an Ilford bashing thread by ex-Kodak employees...
Anáil nathrach, ortha bháis is beatha, do chéal déanaimh.
Please tell me when and where Bill worked for Kodak?
Originally Posted by Photo Engineer
Ron, you seem hell bent on proving that you are right and Ilford are wrong for you have "chewed" this topic to death in your search to be seen to be right, and I'm sorry to say that this is not the first time. I have also witnessed this by other Kodak or ex Kodak employees. For what it is worth the last time I saw Bill Troop was in Montana where I was doing a workshop and Bill was trying to create a new type of developer at my request. When I processed the film I started to wash it in my normal "Ilford" method, Bill's response was "that will take too long just rinse it once that will be quite sufficient, film only needs a quick rinse". We then had a chat when I said I always washed film properly and he agreed with the method I was using.
I had not intended to repeat this because I like Bill very much and did not wish to cast a bad light on a very clever and helpful friend.
I'm not wishing to start any sort of argument with you for I respect you too much but neither an I prepared to sit quiet when you are clearly out to prove wrong Ilford people I know and trust who have constantly assured me that the Ilford washing method is archival.