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  1. #11

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    Quote Originally Posted by Quinten
    -purple spots on the negatives after drying, even after extensive washing. (can the water I use to wash be to cold to be effective?)
    What film are you using when you experience these purple spots?

    Colored residues are often caused by the incomplete removal of sensitizing dye during the fixing and washing process. Tabular grain films seem particularly prone to this.

    To remove these dye residues, I recommend the use of a non-hardening rapid fixer (like one of Ilford's, for example). Use of a post fixing bath, which can be either a 20 - 30 gram/liter solution of sodium sulfite or one of the proprietary Hypo Clearing Agents, is often helpful.
    Tom Hoskinson
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  2. #12

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    I agree with Tom. Might the spots just be incomplete fixing? I tend to find anyway, that T-max and Delta type films benefit from longer fixing than the instructions state. It seems to add a bit more bite to the contrast. I agree the faint negs sound like under development. If it was underexposure the maker's name and frame numbers would come up normal. As for washing water temperature. To avoid any danger of reticulation you can still drop the temp dramatically, but you need to do it very slowly. I fill the tank with water at 20c then run the hose very slowly for a few minutes until the tank drops to the temperature of the tap water and only then run it at normal speed. I give a final wash with a bit of wetting agent in water that has been twice through a chemical filter to remove chlorine, lime etc, again at tap temperature, which by then is what the film has got used to.

    David.

  3. #13

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    Given the clues my guess for the OP: Underdevelopment due to developer improperly mixed - water too cold to disolve so that it has precipitates in bottom of jug.

    Spots possibly due to bubbles from not rapping the tank.

    An aside: tabular films are very hard on fixer. It exhausts faster.

  4. #14

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    Quote Originally Posted by Woolliscroft
    ...I tend to find anyway, that T-max and Delta type films benefit from longer fixing than the instructions state...
    My own results agree. My practice is to test samples of the film I am working with in the fixer to determine the clearing time and fixing time required.

    I take a piece of exposed and undeveloped film, record the fixer temperature and place the film in the fixer, with agitation (room lights on) and record the amount of time required for the film to become transparent. I double the clearing time to determine the amount of fixing time for that film.
    Tom Hoskinson
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  5. #15

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    Thanks for the tips lads.

    I am not sure how I recognise a tubulair film but I shoot with APX100 and Tmax, I've only had purple spots on the APX once after fixing 9 Tmax films with the same fixer. (I change the fixer after ten films)
    So I supose the Tmax is a tubulair film since that's the one being sensetive to the spots. I am using agfafix but will give the non hardening fixer one of you sugested a try.

    Though I think the temprature is the most likely cause for the purple spots, since I wash this cold.

    Michael: Your test already gave me the answer without doing it, I thought the leaks came from a bit of play between the back and the camera but since the exposure on the negs is always at the left it's more than likely the place where the slide goes in. I'll have it replaced.


    Thanks for all sugestions, I've got some things to work with now.

    cheers!

  6. #16

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    Quote Originally Posted by Tom Hoskinson
    I take a piece of exposed and undeveloped film, record the fixer temperature and place the film in the fixer, with agitation (room lights on) and record the amount of time required for the film to become transparent. I double the clearing time to determine the amount of fixing time for that film.
    I do that too. I usually cut the narrow bit off the leader as I load the spiral and then fix that. It also gives you a measure of the state of a particular batch of fix. When the time starts to increase, it's time to mix another batch. Tabular films = T-max and Delta. Possibly others, but they are the ones I use.

    Do you rap the tank after agitation to get rid of bubbles? I tend to bang it down twice on the sink after each aggitation and you still need to do that while fixing.

    David.

  7. #17
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    yes, I didn't think of it earlier, but the temperatures of ALL your baths should be co-ordinated carefully. I have to admit, I am doing it the cheap way - I have a Wal-Mart thermometer that I put under the tap, check the temp, and then mix my chemicals once teh temp has stabilized.

    Like I said earlier, I have had problems with hardening fixers (Kodak), even after almost fanatical washing. My problems were, however, of a more consistent nature, ie. the whole negative had a purplish hue. The spots are the perplexing part. The upper recommended time for fixing in rapid fixer (Ilford) is 10 minutes - and I always tend to use that time with good results. Highly recommend the stuff.

    Also, the faint negs - could yo be more specific as to the nature of the "faintness"? Does it occur alone or always in tandem with the other problems?

    And I am glad i was not totally off the wall with my suggestions about your film back

  8. #18
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    Tabular films include TMAX and Delta - The grain crystals are like flat little plateletts. Regular films have grain that is more 3 dimentional. The differences include; quicker contrast swings with changes in development time and smaller grain structure. I believe they are a development from color film inovations.
    My photos are always without all that distracting color ...

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