 BetterPhoto Member |
My film is coming out purple and odd water marks I have been developing film for a while but I just started doing it in my own darkroom. The first few rolls came out well but then they 2 came out with spots that resembled water spots but they are too faint and consistent, they are on most of the images. Yesterday I developed a few rolls and the first two were fine but the next four came out completely purple. I don't know why it’s purple or why the spots are appearing.
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John H. Siskin |
Hi Kailey, Are you using Photo-flo? It is a product from Kodak designed to prevent water spots. If your water is particularly bad try mixing the Photo-flo with distilled water. If you are using a T-Max film the purple color can be removed by using a hypo-eliminator before the final wash. Thanks, John Siskin
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Alan N. Marcus |
Hi Kailey, The Kodak black & white film T-Max, like all modern films, is made using multiple coatings. One such layer is called an anti-halation coating. Seems that bright light sources included in the photograph (highlights reflected from gemstones or gleams from jewelry etc.) image surrounded by a luminous halo. The halo is due to the bright light striking the junction between the emulsion coat and the film base. This is a junction that re-reflects stray light backwards towards the camera lens. We are talking about, in-the-film internal reflections. These must be minimized -- otherwise a halo like fog surrounds powerful highlights. To minimize halation, a dye layer is added at the junction, emulsion-to-base. The color of the dye is adjusted to the color the film is least sensitive to. The idea is, internal reflections are filtered by the dye coat; thus they transit backwards as a color not likely to be recorded. The dye coat is water soluble; thus is will wash out provided the wash is vigorous. This film needs 20 ~ 30 minutes washing in running water to remove the residual chemicals, the fixer in particular. If not completely washed out, residual fixer, high in sulfur content, attacks the silver image. Given time, this deed stains the film and ruins it. Your purple stain is due to insufficient washing. Likely if washing is insufficient the fixer step is also faulty. You can simply re-wash to remove the purple stain however, I advise re-fixing and then rewashing. Use of the hypo- neutralizer with T-Max minimizes washing time, however these salt-like solutions that effectively neutralize the fixer can cause overconfidence, if the wash step is too short, purple stain results. Alan Marcus (marginal technical gobbledygook)
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Christopher A. Walrath |
Alan's right on the pruple stain. However I use the 5-10-20 washing method that produces sufficient washing of the film after fixing. I fill the tank, invert 5 times, drain. Fill, invert 10 times, drain. Fill, invert 20 times, drain. Cuts down on time and water usage. Follow with one minute in the Photo-Flo and good to go. Squeege the film between two fingers, hang in a still room (circulating air in unpure environment stirs up impossible to clean (so it seems) dust) and let it dry for about thirty minutes, hour prefered. Cut and archive. Chris
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