Switch to English Language Passer en langue française Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 71,849   Posts: 1,582,839   Online: 746
      
Results 1 to 9 of 9
  1. #1
    EmilGil's Avatar
    Join Date
    Mar 2005
    Location
    Sweden
    Shooter
    Medium Format
    Posts
    51

    Color cast from Agfa RA-4 bleach

    Happy as ever before, I went down to my darkroom the other day and started my Nova color processing tank. I knew it hadn't been used for a month because I've been out travelling but I thought I'd give it a shot anyway. After an hour or so, when the temperature was right, at 35'C (95F), I started printing. When I got the first test strips out of the bleach, I was stunned by the color cast, a strong brown-reddish tint.

    After a few strips, I decided that there was nothing wrong with the enlarger; filters working, timer working etc, and that it had to be the chemistry. This batch of working solution was a couple of months old so I threw it away. After cleaning the tanks with lots of water and a cloth, I let them dry. I came back the next day, took out the bottles with concentrated dev and bleach and started mixing. Everything looked and smelled fine, correct color shifts during mixing and a nice-looking final mixture.

    Back to the enlarger, I started making test strips again and got the same result as the day before, a strong brown-reddish cast. I started experimenting, different papers, different enlarging/dev/bleach times and increased filters. Nothing worked. I managed to find out that it is the bleach that is not working, since a developed piece of paper looks ok until I put it into the bleach (a bit pale colors but as expected). Unexposed but developed paper is not affected by the cast.

    I'm using Agfa AP-94 chemistry in a Nova tank processor at 95F, with a Agfa C66 enlarger. The first batch of chemistry was mixed around New Year's and worked fine in late April. The left-over concentrates have been in half-empty, original bottles with caps tight.

    Anyone have a clue? Does the bleach really give in before the dev? I've never seen it before and the guys at the store where I bought the kit scratched their heads for 15 minutes without being able to give me an answer (one of them with years of experience from Kodak labs and one from Fuji labs).
    The camera is merely the means of capturing the image.

  2. #2

    Join Date
    Apr 2004
    Location
    Western Australia
    Posts
    30
    Hi, the only problems I have had with Agfa chemicals and Nova tanks were from developer rather than the fixer dying. I have had definite red/brown casts when my enlarger globe was about to blow, my Jobo analyser couldn't keep pace with the change to the red end of the spectrum.
    This may not be of any help, but then again......
    Mike
    If you live forever, you'll learn everything. Living forever is the problem...

  3. #3
    EmilGil's Avatar
    Join Date
    Mar 2005
    Location
    Sweden
    Shooter
    Medium Format
    Posts
    51
    Brand new halogen lamp, replaced it only a few weeks ago...

    Thanks anyway!
    The camera is merely the means of capturing the image.

  4. #4
    Photo Engineer's Avatar
    Join Date
    Apr 2005
    Location
    Rochester, NY
    Shooter
    Multi Format
    Posts
    23,534
    Images
    65
    Are the borders reddish brown as well?

    Try using a stop bath after the developer and see what happens.

    PE

  5. #5
    EmilGil's Avatar
    Join Date
    Mar 2005
    Location
    Sweden
    Shooter
    Medium Format
    Posts
    51
    If you mean the border between exposed and unexposed paper, the answer is yes, but I assume this is due to not using a very sharp edge to separate the unexposed area from the exposed one. I am using a stop bath, Ilford Ilfostop mixed at 1+19 according to instructions.

  6. #6

    Join Date
    May 2005
    Location
    Daventry, Northamptonshire, England
    Shooter
    35mm
    Posts
    7,150
    Quote Originally Posted by EmilGil
    Happy as ever before, I went down to my darkroom the other day and started my Nova color processing tank. I knew it hadn't been used for a month because I've been out travelling but I thought I'd give it a shot anyway. After an hour or so, when the temperature was right, at 35'C (95F), I started printing. When I got the first test strips out of the bleach, I was stunned by the color cast, a strong brown-reddish tint.

    After a few strips, I decided that there was nothing wrong with the enlarger; filters working, timer working etc, and that it had to be the chemistry. This batch of working solution was a couple of months old so I threw it away. After cleaning the tanks with lots of water and a cloth, I let them dry. I came back the next day, took out the bottles with concentrated dev and bleach and started mixing. Everything looked and smelled fine, correct color shifts during mixing and a nice-looking final mixture.

    Back to the enlarger, I started making test strips again and got the same result as the day before, a strong brown-reddish cast. I started experimenting, different papers, different enlarging/dev/bleach times and increased filters. Nothing worked. I managed to find out that it is the bleach that is not working, since a developed piece of paper looks ok until I put it into the bleach (a bit pale colors but as expected). Unexposed but developed paper is not affected by the cast.

    I'm using Agfa AP-94 chemistry in a Nova tank processor at 95F, with a Agfa C66 enlarger. The first batch of chemistry was mixed around New Year's and worked fine in late April. The left-over concentrates have been in half-empty, original bottles with caps tight.

    Anyone have a clue? Does the bleach really give in before the dev? I've never seen it before and the guys at the store where I bought the kit scratched their heads for 15 minutes without being able to give me an answer (one of them with years of experience from Kodak labs and one from Fuji labs).
    I suppose the guys at the labs asked and indeed you yourself checked that you had put the filters back in place by lowering the white light arm on the enlarger.

    Sorry if this appears to insult your intelligence its just that I once spent the best part of a whole night producing such prints without, for reasons I cannot explain, once going to an obvious cause. In a book on Jobo Processing written by a professional who had his own small time business, I was heartened to discover he had sometimes done the same.

    Pentaxuser

  7. #7
    EmilGil's Avatar
    Join Date
    Mar 2005
    Location
    Sweden
    Shooter
    Medium Format
    Posts
    51
    No insult at all, sometimes the solution is the simplest possible but the filters are working and I can see a shift of color when turning the knobs. I never use the enlarger without filters but I checked the lever anyway.

    Just got a new kit of bleach in sealed bottles from a friend, I'll give that a try in a few days...
    The camera is merely the means of capturing the image.

  8. #8
    EmilGil's Avatar
    Join Date
    Mar 2005
    Location
    Sweden
    Shooter
    Medium Format
    Posts
    51
    Okay, I've tried the new bottles of bleach but no difference in the results, same strong red-brownish color cast. I've contacted the retailer, another professional store, Agfa Sweden and another agent. None of them is able to give me an answer, do I really have to buy a completely new set of chemicals???

    Doesn't anyone have a clue???
    The camera is merely the means of capturing the image.

  9. #9

    Join Date
    Nov 2004
    Location
    Italia
    Shooter
    Multi Format
    Posts
    4,680
    "Ilford Ilfostop"

    Is an indicator stop. Wild guess but try a plain stop. Or no stop to see if it gets better. If it's better with no stop buy some plain stop.



 

APUG PARTNERS EQUALLY FUNDING OUR COMMUNITY:



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