straight hypo--why use anything else?

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Hi all, If it is possible to use straight hypo to fix a print, then I am kind of confused why one would bother to use anything else? Under normal ciccumstances, will a straight hypo solution give you an archival print? What reasons are there to use prepared fixers (other than rapid of course...and hardener)?

Thanks for answering what is probably a dumb question...shawn

-- shawn (shawngibson_prophoto@yahoo.com), August 15, 2000

Answers

The other typical ingredients maximize the effective lifetime of the fixer by reducing oxidation of the thiosulfate and stabilizing (buffering) the pH. Plain hypo will work, but if you exceed the lesser capacity or keeping time of a plain thiosulfate solution, then you risk poorly fixed prints. This is also one of the reasons for using an acid stop bath: developer carryover into the fixer will change the pH, esp. in plain, unbuffered hypo.

-- Michael Briggs (MichaelBriggs@earthlink.net), August 15, 2000.

>> ... will a straight hypo solution give you an archival print?

The answer is a resounding "Maybe!"

In principle, straight hypo is fine, and it will give you an archival print, provided you know the pitfalls and avoid them. Mike has mentioned some of the reasons why one would bother to mix in other ingredients, but for me, the best reason not to use plain hypo is its long fixing time. It allows the hypo to diffuse deep into the paper base, making it hard to wash it out again. Washing out the hypo after one-minute fixing is easier to archival standards is much easier.

-- Thomas Wollstein (thomas_wollstein@web.de), August 16, 2000.


I think Thomas is speaking of using a rapid fixer without hardener, which has an ammonium thiosulfate base for his one-minute fxing time. Using a rapid fix without hardener for fixing paper is the Ilford method of archival fixing. The idea is that the stronger, faster- acting ammonium thiosulfate fixes the unreduced silver salts in the emulsion before it has had a chance to soak deeply into the paper base, thus making wahing easier and shorter. All sodium thiosulfate (aka hypo) fixers necessitate longer fixing times, in the neighborhood of 5-10 minutes for a double-weight fiber-base print. Additions to plain hypo include: an anti-oxidant such as sodium sulfite and buffering agents to stabilize pH. These allow the solution to be used to capacity before being degraded by age or chemical carry-over. Hardeners (boric acid, etc., there are many) are also added to general purpose fixers to harden the gelatin emulsion and therefore prevent handling damage. This is most important with machine processing. When processing carefully by hand, a non- hardening fix can be used which will increase washing efficiency (the emulsion is "open" and the silver compounds can dissolve out more quickly) and therefore, reduce wash times. That said, I prefer a semi- hardening fix for tray processing of sheet films by hand (half the hardener). Zone VI packaged fix is the Kodak F-6 odorless fixer formula with reduced hardener I believe. Rapid fixers give you the option of adding hardener in whatever amount you like. Plain hypo (with the addition of sodium sulfite to prevent oxidation), when used in conjuction with an acid stop and used to capacity relatively quickly (a day or so at room temperature) is a good alternative to packaged fixers. It also has no unpleasant odor, and since there is no hardener washes out quicker than hardening fixers. It is also necessary to use a non-hardening fix before toning prints and with any kind of staining film developer (e.g. PMK).

The rapid fix vs. standard hypo issue is another argument, but suffice it to say that with adequate longer washing, hypo fixers can deliver prints just as "archival" as rapid fixers. Sorry I was so long winded! Regards, ;^D)

-- Doremus Scudder (ScudderLandreth@compuserve.com), August 16, 2000.


It is also necessary to use a non-hardening fix before toning prints and with any kind of staining film developer (e.g. PMK).

Doremus: PARDON?

How do you do this? I tried developing prints once with my regular PMK (my mainstay film developer), actually I added it to Dektol, then used a metaborate afterbath, absolutely nothing happened (other than a pretty regular-looking print). Can you please tell me how to tone a print with PMK? Does it give you that nice (sickly) yellow green I love so much?

-- shawn (shawngibson_prophoto@yahoo.com), August 16, 2000.


I believe an alkaline fixer is what D.S. means regarding use with PMK. The staining takes place at alkaline pH.

If you use traditional hardening fixer the hardener is acid and inhibits the formation of the stain. Gordon Hutchings (I may have his name spelled wrong, sorry) suggests using TF4 fixer from Photographers Formulary, which is alkaline, and a plain water stop bath rather than an acidic one. That way the film stays at alkaline pH throughout the developing process. I get the film to stain just fine. The Book of Pyro by G.H. is really excellent and very helpful if you're going to use PMK.

-- Don Karon (dkaron@socal.rr.com), August 18, 2000.



Thanks. I have the Hutchings book, and use it regularly. As for the print/PMK thing, I resolved that with Doremus privately.

PMK PRINTS: This weekend, I took an old batch of PMK (about 10 months old), and diluted it about 1:10 (ten), and I developed some prints in it. It gave a wonderful tonality I've never got in a print before, and, for the FRIST PRINT ONLY, it gave that wonderful puke green I love so much. But after that, the stain got much less on the second print, and was gone by the third print (I used Kodalk for an afterbath). However, the tonality (notably in skin tones, which were quite...creamy) remained through the rest of my session, which lasted about three hours. But as per the oxidation (and the one-shot nature) of PMK, the developer was brown and sludge by then...and my times increased.

I think my results warrant trying to find a way to use pyro (maybe not PMK) as a print developer. But not at the price of 1/3 of a bottle of PMK per print!!! I'll figure something out and get back to you.

-- shawn (shawngibson_prophoto@yahoo.com), August 21, 2000.


Shawn, Thanks for posting the results of your experiments here. That's what makes this forum such a good place! Keep us posted.

Don, Just an aside regarding your post: I use a non-hardening acid fixer (Kodak Rapid-Fix without hardener or Ilford Hypam) for my pyro negs and then return them to the used developer to help the staining process (as per Gordon Hutchings et al.). The PF alkaline fixer sounds like a better companion to PMK developing, but I haven't tried it yet. I imagine it is meant to be used without a hardener also.

Regards, ;^D)

-- Doremus Scudder (ScudderLandreth@compuserve.com), August 21, 2000.


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