the magenta cast on the film does either result from anti-halation dyes or from sensitization dyes, depending on the film type. Use a 2 min wash instead of a stop bath after development or use two-bath fixing. Two-bath fixing is a good thing and usually yields the clearest base possible. Mix two bottles of fixer and apply each half the necessary time (previously determined). The first bottle exhausts much faster than the second one does. When the first bottle is exhausted, replace it with the second one and mix a new one for that.
I've often ended up with a very noticeable magenta or pink tint on TMX and TMY, but I haven't used these films in years and don't plan to again, and I've changed my processing regimen since then. I have never seen even a hint of a residual tint with HP5 or FP4+, both of which I use fairly regularly.
My process is 2 minutes in plain water presoak, develop in ABC Pyro or PMK, 30 second stop in Kodak Indicator Stop bath at standard dilution, six to eight minute fix in Kodak F-24 nonhardening fixing bath, five minutes in Kodak Hypo Clear or Heico Permawash, and 20 minute running water wash.
I don't know if the pink or magenta tint is related to the dyes that come off in the presoak water or not, but I'm always amazed at the color of my presoak water when I turn the lights on. It's always a very dark and opaque blue or green color, depending on the film.
this is an issue with the Kodak TMAX films. A 2 minute soak in 2% solution of Sodium Sulfite will remove any trace of the pink tint on any of the TMAX brands. For whatever reason, that tint will not come out to easily. The resoak in spent PMK will remove any trace also.
Different manufacturers films have slightly differing dyes in or on their emulsions for various purposes. The antihalation dye is on the side opposite the emulsion and comes off or clears in the developer. The residual color is the result of some sort of sensitizing material in the emulsion. It is a little harder to remove and, based of many observations, is related to water quality. I found that the Kodak TX clears of color by allowing the film to stand quiescently in a water bath after fixing. The film base also has some effect, as my 4x5 TX clears readily in the tray of water awaiting final wash. I have not had a problem with HP5+ as it seems relatively clear from the second fixer bath. PXP sometimes exhibits a bluish cast that also goes in water – not fixer.
I strongly recommend (and commend other contributors who mentioned this) a two-bath fixer technique. You cannot be safer and it will cost less in the long run.
Truly, dr bob.
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Truly, dr bob.
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I think you are right to use your own chemistry in a college situation. I am not a chemist but I do believe that fixer that has been over used will contain other chemicals that are generated as the fixer ages. I have been told that these chemicals are difficult to wash out and are likely to cause deterioration in the negative at a later date. That being the case it is possible to appear to fix a film by extending the time when in fact all you have done is create a built in self destruct system. My own procedure for use of chemicals is once only for developer and twice for fixer so that the maximum number of films through any batch of fixer would be 10.
I teach part time in Edinburgh College of Art and will not allow any cost cutting of this nature for it is an absolute false economy and I would encourage you to point this out to the college you attend.
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</span><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (Les McLean @ Apr 8 2003, 01:27 AM)</td></tr><tr><td id='QUOTE'>I teach part time in Edinburgh College of Art... </td></tr></table><span class='postcolor'>
Usually, those who teach at Art Colleges are *NOT* very good artists. I would suggest that you are a MAJOR exception to that stereotype, Les. Wonderful work as Photogapher of the ... whatever time period.
I'd sign up for your classes in a heartbeat.
</span><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (Les McLean @ Apr 8 2003, 02:27 AM)</td></tr><tr><td id='QUOTE'> I am not a chemist but I do believe that fixer that has been over used will contain other chemicals that are generated as the fixer ages.
</td></tr></table><span class='postcolor'>
I used to just fix and pray - I ruined some film that way. - Not any more though. I mix my fixer and I have a series of boxes on the side of the bottle. 20 8x10 of film per liter. I mix 1.25 liters to give me a safety margin and to completely fill my Jobo - If I don't cover the film completely, the PMK will leave an uneven stain. I check a box for each roll of film or group of 4x5 negs and dump it when it is time. The only chemical change I am aware of is all the silver and silver compounds in the fixer when it has been used. I believe I can get 40 8x10 prints out of the Fixer I am using - although I keep my print and film fixer seperate. i use photoformulary TF4 - It is archival and it doesn't degrade Gallol or Catechol stains.
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My photos are always without all that distracting color ...
I was just developing a bunch of 35mm film and did a pre-soak. To my surprise no color change to the water when I dumped it. Would a pre-soak still benefit a 35mm roll? With MF I still get the anti-halation layer coming off and coloring the water so can see a benefit there. I was using FP4 for 35mm.
Eric
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