Switch to English Language Passer en langue française Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 69,986   Posts: 1,523,990   Online: 789
      
Page 1 of 4 1234 LastLast
Results 1 to 10 of 34
  1. #1
    jstraw's Avatar
    Join Date
    Aug 2006
    Location
    Topeka, Kansas
    Shooter
    Multi Format
    Posts
    2,703
    Images
    42

    Formulary Fixer Test, film, paper, testing, capacity and times.

    Yes, all of that...

    I think that in the past I've been guilty of discarding un-exhausted fixer. I want to use it to exhaustion and think about silver recovery.

    If I use it to exhaustion, as determined by testing, will I be able to count on using the same fixing times for film and and paper right up to the point of exhaustion or do I need to make any adjustments as I approach that point?

    I'm assuming I can track how many prints/sheets/rolls it takes to reach exhaustion for film and for 1st and 2nd print trays to establish a baseline so I can track how close to typical exhaustion I am and to then test.

    What insights can you folks share on this subject?
    Lorem ipsum dolor sit amet, consectetuer adipiscing elit. In velit arcu, consequat at, interdum sit amet, consequat in, quam.

  2. #2

    Join Date
    Jun 2003
    Shooter
    Multi Format
    Posts
    15,947
    hi michael

    an easy way to determine if your fixer is used to capacity, or nearly to capacity ( i am sure some will tell me i am wrong )
    is to do a clip test ...
    take your favorite film and open it in daylight in your darkroom so it is totally exposed to light ...
    clip off about 1 square inch of film.
    put that film in your fixer ( lights on ) and watch the clock. when it clears to base note the time.
    double that time for your film fix time .. so if it is 30 seconds ... your fix time for this film is 60 seconds.
    split it between 2 baths ... 30 seconds in each ...
    paper .. fix it to your manufacturer's recommendations ... split it again between your 2 baths ...

    when your fixer takes 2x the original "fresh fix" clip test ( so 1 min in our example ) your fixer is spent and shouldn't be used anymore ...

    remove #1 for recovery ( or hauling or whatever your situation is ) make your #2 your new #1 and make a NEW second bath.
    do your clip test whenever you process film / print so you know if you are spent &c ..

    the thing with 2 baths is the first bath does most of the heavy lifting, and bath 2 does clean-up ...

    "the drops" ( like edwal's hypo check ) will give you a false reading, unless you are using edwal's fixer, and often times
    people don't really take out 1oz put a the drops in and swirl it to see if it is reabsorbed so they get a false reading that way too ...

    the thing about the fix test is to use the same film you always use so the silver content of the film won't be different between the test and your film ...

    good luck !
    john
    im empty, good luck

  3. #3

    Join Date
    Jul 2010
    Location
    Southern USA
    Shooter
    Multi Format
    Posts
    3,769
    I agree with John. The best way is to keep track of the amount of film/paper put through a bath. The check solution is realy not that accurate.
    A rock pile ceases to be a rock pile the moment a single man contemplates it, bearing within him the image of a cathedral.

    ~Antoine de Saint-Exupery

  4. #4
    jstraw's Avatar
    Join Date
    Aug 2006
    Location
    Topeka, Kansas
    Shooter
    Multi Format
    Posts
    2,703
    Images
    42
    I'm talking about Photo Formulary's Fixer Test, not those cheapo drops.

    So I understand, you're saying use 2x time-to-clear with film to test exhaustion of fixer used for prints as well as for fixer for film, yes?

    Thanks...
    Lorem ipsum dolor sit amet, consectetuer adipiscing elit. In velit arcu, consequat at, interdum sit amet, consequat in, quam.

  5. #5

    Join Date
    Jul 2010
    Location
    Southern USA
    Shooter
    Multi Format
    Posts
    3,769
    It really doesn't matter who makes the test solution. By its very nature the test is not that accurate. Part of the reason is that it requires the user to make a rather subjective decision. PF in their directions should give the recommended capacity for the fixer. As fixer nears the end of its useful life it becomes harder and harder to remove silver complexes. This can cause degradation of prints and films which may not be immediately visible. Film and paper are expensive, fixer is cheap. Scrimping on fixer is a foolish economy.
    A rock pile ceases to be a rock pile the moment a single man contemplates it, bearing within him the image of a cathedral.

    ~Antoine de Saint-Exupery

  6. #6

    Join Date
    Aug 2006
    Shooter
    Multi Format
    Posts
    321
    If I use it to exhaustion, as determined by testing, will I be able to count on using the same fixing times for film and and paper right up to the point of exhaustion or do I need to make any adjustments as I approach that point?
    I think the standard approach would be to find a fixing time that is acceptable as your system becomes "exhausted," then always use that time. When you have fresher chemicals, the fixing time is on the long side, but who really cares?

    The trickier thing is deciding what "exhaustion" actually is. The easiest thing is to follow the procedure spec'd out by the manufacturer of your materials, assuming you can find such a thing. Otherwise, the responsibility falls on you.

    That said, I pretty much agree with John (and Gerald). The only thing I'd do differently is to check the silver concentration in the "clean" tank. I'm not up to date on this, but "silver estimating papers" used to be commonly available. These were typically used for roughly 1 to 10 grams/liter silver. You should check other sources for actual recommendations, but my fuzzy memory says that under about 1.5 g/l for film, and under about 1/2 g/l for fiber paper is fine for high-grade processing. Whenever either of 1) first fix time gets too long, or 2) last fix gets too much silver, then you bring in some fresh fixer and shift the tanks.

    Counting the volume of material processed is a little iffy for B&W, since it actually depends on how much silver was developed. If you do mostly high key photos, then the great majority of the PAPER's silver must be removed in the fixer, whereas mostly black photos will barely use up the paper fixer. (For color materials, it doesn't matter since ALL of the silver ends up in the fixer.)

    If you're interested in more details, I talked about replenished fixer systems in this thread, starting with post #31. http://www.apug.org/forums/forum37/1...l-fixer-4.html (I don't think you'll get any practical use out of it, but you might say "Oh, now I see why they're doing that.")

    ps: Gerald's latest post, "fixer is cheap," is right. In real-world commercial processing, the main reason for multi-stage fixing is to maximize silver recovery and to help meet environmental regulations.

  7. #7

    Join Date
    Jun 2003
    Shooter
    Multi Format
    Posts
    15,947
    sprint systems of photography makes developer, stop, fix and fix remover ( and other stuff ) for both film and paper. they call their chemistry a system because
    when the stop bath indicates it indicates when EVERYTHING is spent ... their fixer is high capacity "speed fixer" ... you may write or call them
    to see if using their stop+fix instead of all 4 if you like using other chemistry? to see if the stop will still indicate for the fixer. it might make your life easier
    because you don't have to deal with tests which may be useful, confusing or a PITA ....
    not saying not to use the formulary-stuff but i used it years ago and it had a scent i couldn't get used to, so i went back to using sprint fixer.
    its a liquid concentrate, lasts and lasts and doesn't reek ... some of their chemicals smell like vanilla too ..
    im empty, good luck

  8. #8
    jstraw's Avatar
    Join Date
    Aug 2006
    Location
    Topeka, Kansas
    Shooter
    Multi Format
    Posts
    2,703
    Images
    42
    Quote Originally Posted by Gerald C Koch View Post
    It really doesn't matter who makes the test solution. By its very nature the test is not that accurate. Part of the reason is that it requires the user to make a rather subjective decision. PF in their directions should give the recommended capacity for the fixer. As fixer nears the end of its useful life it becomes harder and harder to remove silver complexes. This can cause degradation of prints and films which may not be immediately visible. Film and paper are expensive, fixer is cheap. Scrimping on fixer is a foolish economy.
    I understand your point and don't disagree. But I also view water conservation, minimal use of pollutants and maximizing the capability for silver recovery as important. It's not about the cost of fixer.
    Lorem ipsum dolor sit amet, consectetuer adipiscing elit. In velit arcu, consequat at, interdum sit amet, consequat in, quam.

  9. #9
    jstraw's Avatar
    Join Date
    Aug 2006
    Location
    Topeka, Kansas
    Shooter
    Multi Format
    Posts
    2,703
    Images
    42
    Quote Originally Posted by Mr Bill View Post
    The only thing I'd do differently is to check the silver concentration in the "clean" tank.
    I'm not sure what you mean by "clean tank."
    Lorem ipsum dolor sit amet, consectetuer adipiscing elit. In velit arcu, consequat at, interdum sit amet, consequat in, quam.

  10. #10

    Join Date
    Sep 2002
    Location
    Oregon and Austria
    Shooter
    4x5 Format
    Posts
    833
    Michael,

    Fixer doesn't have an exhaustion point that's really easy to nail down. I depends more on the amount of residual silver you are willing to live with in your film/paper and the amount of safety margin you want in your fixing regime so that you don't use fixer that is too full of unwanted silver compounds to fix with.

    Ideally, we could easily measure the amount of dissolved silver in a fixing bath accurately down to the small levels that are needed (e.g., 0.2g/l for optimum permanence for fiber-base prints). Unfortunately, this is not practical for the typical darkroom worker. This is why you need an adequate safety factor (read, you don't really want to work at the edge of exhaustion; it's just too risky if you want optimum permanence).

    My solution to get the most of my fixer while still ensuring optimum fixing is to use two-bath fixation whenever possible, even for film.

    For film, do a clip test on your first bath before each batch. I triple the time instead of doubling it; some modern films do take longer to fix due to the silver iodide in the emulsion, and a safety factor for film can't hurt, since it is on an impermeable base. This time I divide between the two baths. When the clearing time for the clip test is double that in fresh fix, bath 1 is sent to silver recovery and bath 2 takes its place. If you develop film regularly, then you can keep the system going for the full seven changes before the fixer is too old (see below).

    For fiber-base prints, don't take any chances, especially if you want optimum permanence. First, try not to overfix; use a minimum time and a safety factor on capacity. I use throughput as a guide and discard bath 1 somewhat before the recommended capacity is reached just to be sure. You'll still have a lot of silver in bath 1 to recover if you do this. It's just much better to err on the side of caution here IMO. I use 36 8x10 per liter as a maximum throughput (slightly less than Ilford's recommendation). If you use another fixer, read the manufacturer's recommendation. Again, when your capacity for the first bath is reached, replace it with the second. This can also go through seven changes till you should discard both baths and start over. Or discard when the maximum age of the fixer working solution has been reached, whichever comes first. Ilford recommends the following for fixer lifespan: 6 months in full tightly capped bottles, 2 months in a tank or dish/tray with a floating lid, 1 month in a half full tightly capped bottle or 7 days in an open tray.

    Test your system at the beginning and then regularly thereafter for residual silver using the Kodak ST-1 residual silver test to make sure your fixing to an acceptable standard (and do the HT-2 residual hypo test while you are at it to test if you are washing adequately as well). Both these tests are available from the Formulary (with different proprietary names, but the same tests).

    The above will give you peace of mind, get the most out of your fixer and ensure you aren't sending unused or partially used fix to silver recovery.

    Best,

    Doremus


    www.DoremusScudder.com
    Last edited by Doremus Scudder; 10-04-2013 at 11:15 AM. Click to view previous post history.

Page 1 of 4 1234 LastLast


 

APUG PARTNERS EQUALLY FUNDING OUR COMMUNITY:



Contact Us  |  Support Us!  |  Advertise  |  Site Terms  |  Archive  —   Search  |  Mobile Device Access  |  RSS  |  Facebook  |  Linkedin