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Photo Forum / Film Photography / Darkroom / November 2004Image vanishing!
Hi all, Yesteday I printed a few images on Ilford MG warmtone fiber paper. One of them was quite underexposed, but there was an image to see. However, after fixing, washing and hanging to dry, I found that the image had all but vanished. This was after a few hours. I tried to get the image back by placing the print in brown toner solution. I was hoping that if the image had somehow become rehaloginated, it would develop again into silver, but it did not happen. Another test strip also bleached partially in the fixer itself after 40 minutes of sitting in the fixing bath. What causes this? Has anyone experienced similar things? Thanks in advance, -Sreenath > Hi all, > [quoted text clipped - 16 lines] > Thanks in advance, > -Sreenath We need to know how long you fixed the image and at what fixer to water dilution.  SignatureLF Website @ http://members.verizon.net/~gregoryblank "To announce that there must be no criticism of the President, or that we are to stand by the President, right or wrong, is not only unpatriotic and servile, but is morally treasonable to the American public."--Theodore Roosevelt, May 7, 1918 >Hi all, > [quoted text clipped - 16 lines] >Thanks in advance, >-Sreenath Hi Sreenath, It sounds as though your fixer is exhausted. Do you have any "Hypo-Chek" or equivalent solution with which to test the fixer? If not, the first test is to make fresh fixer, repeat the process and see what happens. Francis A. Miniter > >Hi all, > > [quoted text clipped - 25 lines] > > Francis A. Miniter Exhausted fixer will not cause the fading of the image during fixing or washing. It will cause degradation of the image after a considerable time. A partially exhausted fixer will clear the emulsion but may not convert all the unused halides into completely soluble form or leave them tightly bound to the image silver. Treating a print or film which has residual halide in it with a sulfiding toner like Kodak Brown Toner or a Sodium sulfide solution, or a strong dilution of Kodak Rapid Selenium Toner, will tone the remaining halide leaving a quite noticable stain. A solution of Sodium Sulfide is the standard test for residual silver in emulsions. A 1:9 dilution of KRST will also work providing the material has been well washed: an excess of hypo prevents the stain. Richard Knoppow Los Angeles, CA, USA dickburk@ix.netcom.com >Hi all, > [quoted text clipped - 11 lines] >Another test strip also bleached partially in the fixer itself after >40 minutes of sitting in the fixing bath. Too long in the fix. Howlong did you fix the first print? Was it Sodium or Ammonium? >What causes this? Has anyone experienced similar things? > >Thanks in advance, >-Sreenath Robert Vervoordt, MFA > >Hi all, > > [quoted text clipped - 21 lines] > > Robert Vervoordt, MFA Thanks for all the responses. The fixer is quite old, but not exhausted. I brown toned a few prints that I made in the same session, and there were no yellow stains. I understand that if the fixing was incomplete due to exhausted fixer, the remaining halide must have immediately turned yellow in the toning bath. Am I right in this? The fixer is Sodium Thiosulfate mixed with Ammonium Chloride to get a sort of rapid fixer. I have stored this for at least two months now and have been resuing it still!!! How does exhausted fixer cause image bleaching? -Sreenath >> >Hi all, >> > [quoted text clipped - 37 lines] > >How does exhausted fixer cause image bleaching? It's not exhausted, and it's got most of the speed up of Ammonium salt. There may have been some extra components picked up along the way in its prior use. I think the paper might have been in the fix too long. Sorry not to be more helpful. Robert Vervoordt, MFA > Another test strip also bleached partially in the fixer itself after > 40 minutes of sitting in the fixing bath. > > What causes this? Has anyone experienced similar things? Forty minute fix. Was that an experiment? I've only heard that a long fix can bleach. I've never heard why. Fix itself is a reducing bath, not at all a bleach. The THIO is sulfer and stands in place of one oxygen so it is a THIOsulFATE rather than SULFER sulFITE. I think a long fix may bleach due to the action of oxygen in a shallow solution on the metalic silver. The silver is likely of near colloidal size and easily affected. I've doubts that the concentration of the fix has much to do with the bleaching. Be the fix much or little dilute the oxidized silver will be fixed out. Anybody got a better theory? Dan > > Another test strip also bleached partially in the fixer itself after > > 40 minutes of sitting in the fixing bath. [quoted text clipped - 13 lines] > silver will be fixed out. > Anybody got a better theory? Dan I wonder how long the prints were fixed. The 40 minute time seems to be for the test strips. Ammonium thiosulfate (rapid) fixer when acid will act as a solvent for metallic silver but it takes some time. Warm tone paper has very fine silver particals as you point out so is more vulnerable to bleaching in the fixing bath. BTW, Kodak recommends rapid fixer with 15 grams per liter of citric acid added as a reducer for dichroic fog, which is colloidal silver, so it will definitely remove metallic silver. Rapid fixers diluted to film strength should fixe out paper emulsions in 30 seconds to a maximum of around 2 minutes for some unusual papers. Most papers should be fixed in one minute. Neutral or alkaline rapid fixer does not bleach. Richard Knoppow Los Angeles, CA, USA dickburk@ix.netcom.com > Dan Quinn wrote > > > [quoted text clipped - 27 lines] > unusual papers. Most papers should be fixed in one minute. > Neutral or alkaline rapid fixer does not bleach. He is not being clear about that fix time. I do not believe ammonium or thiosulfate in themselfs will dissolve elemental silver. Both of them will complex, thio the more so, with oxide and sulfide of silver. So, with long immersion any silver oxide or sulfide produced will be dissolved. Over long periods a little hypo-alum action may be going on. As for 'film' vs 'paper' strength and speed of fixing, I'm more and more of a mind that an entirely incorrect read has been given the matter. That includes Martin Reed's read. In a nut shell I'm more inclined to think that the entire matter of 'film' strength fix is capacity related. FAST and THICK just don't go togeather. Dan Sreenath, Can you describe precisely what you did? I hardly can imagine that an image disappears after developing, fixing and washing, just in a few hours. I can imagine that the highlights become stained, due to bad/insufficient fixing, but the shadows, once formed, normally do not disappear within a few hours. Only if the paper was soaked with some oxidizing liquid, I can imagine that all black metallic silver is oxidized to colorless Ag(+), such that the image disappears, but then you probably have a really weird fixer or a really weird washing liquid. Wilco > Sreenath, > [quoted text clipped - 10 lines] > > Wilco Hello, The two prints that have suffered this way are : 1. test print, exposed in terms of 15 seconds(15, 30, 45, .. 90) There was progressive density as can be expected. I left the print in the fixer for 40 minutes since I went out for a walk. After coming back I found that the lower strips had vanished. The more exposed ones were still there, though the density was greately reduced. This also faded somewhat on drying. 2. The other print was really underexposed, mistake on my part. There was a image visible. This one was fixed for normal duration, ( a few minutes) and then washed and hanged to dry. This one faded during drying. I think Richard Knoppow has pointed out something important. The two prints have become yellow. Is this because of dichroic fog? Even the test strip that has the faded image has also turned yellow. I did not use stop bath. I had a tray filled with water(2 liters) and I simply dipped the print there for a minute. Possibly the alakli has entered the fixer in a big way. So a combination of a rather old fixer, nearing exhasution and mixing of alkali had something? Thanks, Sreenath >> Sreenath, >> [quoted text clipped - 61 lines] > Thanks, > Sreenath Dichroic fog is a deposit of very fine elemental silver on the surface of film or paper. On film it looks yellowish by tranmission and bluish by reflection. On a print it probably would look yellow. I am not saying this is what you got, but its a possibility. Dichroic fog can come from well used developer that has a lot of silver dissolved in it. In combination with carried over developer fine silver can be generated in the bath. This happens only with very well used fixing bath. OTOH, it seems to me very unlikely such an exhausted fixer could bleach out the silver image. I am more suspicious that something got into the fixing bath causing the problem. I have no idea what this could be. Normally a bleach that will remove a silver image is a very stong bleach, much stronger than any bleaching action from a fixing bath of any sort. As I stated in another post to this thread, Kodak recommends a solution of rapid acid fixer with a small amount of citric acid added to remove dichroic fog from film. This solution will bleach highlights if the film is left long enough but I think it would not ever completely remove the image. I am puzzled by this as I think Donald Qualls is, its very unusual. I think something else was going on here but I can't even guess at to what. Again, the normal bleaching action of acid rapid fixer is such that it can cool warm tone papers a little and given long enough remove some highlight detail, but not remove an entire image. Even the slight bleaching takes say 15 minutes or more in fresh fixer. Since papaper should fix out in no more than two minutes, and usually in half that, in rapid fixer its not usually a problem unless the paper is left in the fixer for an inordinate amount of time. Signature--- Richard Knoppow Los Angeles, CA, USA dickburk@ix.netcom.com >Hello, > [quoted text clipped - 24 lines] >Thanks, >Sreenath Whatever about the cause of the problem, 40 minutes in fixer is really excessive. For an RC print, two minutes is probably correct. Many of us use a two bath method. A minute or so in the first bath, and a minute or so in the second bath. When the first bath is exhausted, the second bath becomes the first bath and a fresh second bath is prepared. Not using stop bath is not a problem IF you use a water rinse at the very least to keep developer transfer to the fixer at a minimum. As I mentioned in an earlier post, use Hypo-Chek to determine whether the fixer is exhausted. Francis A. Miniter >>Hello, >> [quoted text clipped - 53 lines] > > Francis A. Miniter I agree completely with this. Signature--- Richard Knoppow Los Angeles, CA, USA dickburk@ix.netcom.com > Not using stop bath is not a problem IF you use a water rinse ... ... with neutral to alkaline fixers. Acid stops are generally recommended for Acid fixers. The acid in an acid stop is there to maintain the acidity of an acid fix. Acid stops run apx. 98% water. Numbers alone dictate the great effect water has on 'stoping'. The swift nature of the water molecule compared to that of the usuall acid molecule only increases it's effect. There is no point in using an acid stop with other than an acid fix. The usual few second dip will confer enough acid to the paper to maintain the acidity of the fix. I use a water STOP, if any at all, with neutral and alkaline fixers. Dan |
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