The Ilford wash method has been pretty much disavowed by its author (Mason) in his textbook. If he kind of discredits it, then who can we believe?
OK between Ulrich's link article ( thanks Ulrich), TEX's experience of 25 years and that of Roger Hicks and Les McLean ( both more than 25 years) I'll stick to the Ilford 5/10/20 inversions and dumps. Oh and then 10/5 on the way down - just for luck, you understand
The major problem I see in the Ilford wash method is the great unknown - carry over
How much of the previous fix/wash water are you carrying over to the next wash
If you make some basic assumptions on the assumption of zero carry over and then do the same calculations but with even fairly small quantities of residual fixer sol'n then the number of wash cycles increases dramatically.
I am always amazed when I empty a film tank how much liquid stays in at the first pour out, leave it a minute and do it again there is plenty more - and then does not take any account of the liquid on the film and spiral
Testing will always help verify the quality of any wash method.
Mason's math and reasoning has shown me how careful you must be, because without proof, any error will not show up until your prints are 20+ years old. I have some of the first prints I ever made from the time I was about 12, and they looked great to me. Recently, I found some of them in an album and they were all brown and spotty.
I may be wrong here, and thinking of the wrong thing, but when i'm finished developing, stopping and fixing, I just set the tank under running water dumping every time its full for about 2 min. I'm "done", when I don't get that faint purple tent to the water anymore. Course, that could be an error on my part. Perhaps I missed what the subject of conversation was?
So I guess my "method" goes something like this: Develop, rinse a time or two, stop, rinse a time or two, and fix, then rinse a lot...
I guess from a chemists point of view, a wait period where the film set in still water would allow the water to "extract" bad stuff until it was saturated, then you would need to dump. Thus, I guess my "wash till the purple is gone" method would conserve water by doing less actual rinses... who knows...
Tom. It just seems to me that Ulrich's article does involve scientific comments on neg washing. I was simply saying that short of an article that proves unequivocally that the Ilford method fails to deliver archival negs and short of similar conclusions to a similar effect from two eminent photographers who have developed and printed for nearly 40 years plus TEX's experience that maybe a conclusion that the Ilford method works was a reasonable assumption.
I don't know about you but I doubt if I'll have any interest in my negs beyond the next 25 to 30 years max due to age. That's my age not the negs:(
I hope either you or someone else does have an interest in them.Quote:
I don't know about you but I doubt if I'll have any interest in my negs beyond the next 25 to 30 years max due to age. That's my age not the negs
For the record I use a combination of continuos flow and standing water diffusion for film, not rigorously tested as of yet though. I process film in a Jobo as well as Paterson tanks and trays so perhaps PE might be able to comment on potential washing efficiencies based on processing method. I am planing to test for washing soon. I suspect some process issues may turn up in the shorter term as well. Today I use film fixer either one shot or for a limited number of films; however when I got started processing my own film in 2003 I used the film fix many times, but within ILFORD stated capacities. Even so, something may show up.
Well, Mason's book contains equations that are applicable to both film and paper both. They relate to the concentration of hypo+silver complexes with respect to time of wash in still and running water.
So, from that sense, you cannot differentiate in the equation between film or paper as it is independant of medium. It depends on rate of change. Thick film or paper washes more slowly than thin film or RC. I have published this entire portion of his work in simplified terms twice on APUG. It usually confounds people, but the bottom line is that the concentration of material in the photo material must change. If you use standing water or no agitation or both, then an equillibrium is reached and concentration is no longer changing. It becomes static or stagnant! You must agitate with running water to get the best wash. It is done when the material tests free of Silver and free of Hypo with appropriate test kits. This will vary depending on your water supply.
On another tack though, Haist reminds us that Metol washes out in an acid fix but HQ does not and in subsequent washes, Metol + acid fix is faster washing out in water but HQ + alkaline fix is faster washing in water. This is an interesting quandary.
The Dimezone/Phenidone family are more or less neutral wrt fix.
So, Haist suggests using something to swell gelatin (pH in this case) to speed washing and this is how TF-4 works. I'll have more to say on that in a few weeks perhaps, because there are other ways to swell emulsions and speed washes.