Robert, Not disputing you, but can you point us to the source for that number?
I'm always suspicious of "archival standards". A gallon of fix for a single 16x20 piece of paper? I'd like to hear from PE on this.
It does seem exceptionally low, especially if you're doing a 2-bath fixing scheme.
But, I'm here to listen & learn...
No idea where the 4 10x8 prints per gallon comes from even with the under measure US gallon that's excessively wasteful.
This would have to be using a single bath, but I agree that it's an exceedingly low number.
"I only wanted Uncle Vern standing by his new car (a Hudson) on a clear day. I got him and the car. I also got a bit of Aunt Mary's laundry, and Beau Jack, the dog, peeing on a fence, and a row of potted tuberous begonias on the porch and 78 trees and a million pebbles in the driveway and more. It's a generous medium, photography." -- Lee Friedlander
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In response to the above, apologies for the misunderstanding. I was somewhere else for the moment.
Let me shed a little more light on this which is a constant question for many. This quote comes from the Pure Silver list and the PS lists long time equivalent of our own PE.
read what was stated above then went out to verify what is on the Ilford site and found a discrepancy. Ilford in their Hypam rapid fix PDF gives a capacity of 40 8x10 sheets per liter for fiber, 80 sheets for rc.
The document also states that a 2 bath fix is much more economical.
Richard, could you respond to this please and help me clear up any
The 10 sheets per gallon were in a paper on archival processing using the Ilford Archival wash method for fiber paper. In this the exposure of the paper to the fixing bath is very short to minimize the amount of fixer absorbed into the fibrous structure of the support. The support holds the fixer so that it does not wash out by strictly diffusion as it does from the emulsion. Ilford recommends fixing times no longer than one minute but there is still an advantage of times less than two minutes. Many papers will not fix out in this short a time even in the film strength rapid fixer specified by Ilford. The capacity of ammonium thiosulfate fixers appears to be somewhat greater than for sodium thiosulfate fixers but I've never seen any formal research on it. The capacity of the fixing bath also depends on how much residual silver halide is permissible in the emulsion. The residual halide will eventually change in form and cause staining and loss of the image. After some relatively short period, about two weeks, the residual halide changes to a form which will no longer be removed by subsequent re-fixing. Where the life of the print does not have to exceed about ten years the residual silver level can be much higher than when great permanence is required. Most of the fixing bath capacities are given for such "commercial" levels of residual silver rather than for "archival" purposes. That may account for Ilford's high capacity for its rapid fixer. The use of two successive fixing baths results in an increase in _archival_ fixing capacity of from four to ten times. The use of a sulfite wash aid, such as Kodak Hypo Clearing Agent, subsequent to fixing will extend the capacity a little more because it makes some otherwise insoluble thiosulfate-silver complexes soluble. Since fixing is an exponential process the first bath absorbs most of the silver from the emulsion leaving the second bath fresh enough to complete the fixing process. The routine is to used the two baths until the first becomes too saturated with silver and then discarding it, making the second bath the first and replacing the second bath with a fresh bath. This can be done perhaps five times after which both baths are discarded and one starts out with two fresh baths. The same system works for film or paper. It used to be recommended that the same fixing bath NOT be used for both film and paper. I think this was partly because of the accumulation of iodide from film. Iodide is a slight restrainer of fixing. However, it also helps in washing. In a two bath system the iodide will mostly come out in the first bath. The other reason is probably to avoid dyes from film anti-halation layers or sensitizing dyes which may come out in the fixer. I've never experienced staining from this cause and am skeptical that it exists.
Los Angeles, CA, USA
I agree it could be wasteful, and exactly for that reason I was asking for a simple & cheap formula.
sodium sulfite andmeta bi sulfide arePreservativesand buffers are used with acid fixers to prevent an accumulation of sulfur, due to a reaction of thiosulfate with acids. This is achieved by adding sodium sulfite, which quickly reacts with colloidal sulfur and creates fresh sodium thiosulfate.metabisulfide.and stabilize the pH value of acid and alkali fixers. If alkali fixers are preceded by an acid stop bath, sodium carbonate must be substituted with sodium metaborate or balanced alkali to avoid the formation of carbon-dioxide gas bubbles.also, in washing aids:Buffers such as sodium sulfite and sodium carbonate are used to stabilize the pH value of acid and alkali fixers. If alkali fixers are preceded by an acid stop bath, sodium carbonate must be substituted with sodium metaborate or balanced alkali to avoid the formation of carbon-dioxide gas bubbles.
Originally Posted by pierods
Don't waste fixer - go to a two bath fixing procedure - There are enough references to this on the Wise and Wonderful Web to not need me to repeat
Regarding one shot print development, if that is what you mean, that is only needed for Amidol
For film development I use a deep tank of D76d started in May 1985 and replenished ever since - Yes, almost 27 year old film developer still in use - Like me, it improves with age, but to be honest I use a rigorous replenishment system and I doubt if there are any molecules from 1985 still in the mix
Sometimes I give away 500ml to photographers who are setting up a deep tank line - It goes in their mix like a kind of apostolic descent - I digress
Last edited by John Austin; 01-05-2012 at 07:49 AM. Click to view previous post history.
Reason: spelling errors, too prolix and too much digression
I think you could get away with just a solution of sodium thiosulfate. It can't get any simpler than that. 160g per liter if it's anhydrous, or 250g per liter if it's crystallized. Mix only the amount you need to cover the film in the tank, and use it quickly, as it goes bad in a couple of hours.
Originally Posted by pierods
I wouldn't bother with sulfite or metabisulfite if I had to develop just one film and then throw the fixer away.
That being said, I find this method a bit too wasteful for my taste. You'd probably get two or three films per liter, while a bit of preserver would make the fixer last for several months and develop at least ten films per liter, if not more.
Last edited by Vlad Soare; 01-05-2012 at 08:30 AM. Click to view previous post history.