Switch to English Language Passer en langue française Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 70,536   Posts: 1,544,096   Online: 1007
      
Page 2 of 4 FirstFirst 1234 LastLast
Results 11 to 20 of 40
  1. #11

    Join Date
    Feb 2010
    Location
    Montreal, Canada
    Shooter
    Multi Format
    Posts
    4,731
    I didn't mean it halts development like an acidic bath. Let's call it a water rinse, then. In any case, as long as a water rinse is used when testing and consistently thereafter, it should not be an issue.

  2. #12
    Leigh B's Avatar
    Join Date
    Jan 2011
    Location
    Maryland, USA
    Shooter
    Multi Format
    Posts
    1,035
    Images
    1
    As long as the process works and consistently yields the expected results, the details don't matter.

    My comment was just a matter of semantics, for those who might retrieve this thread from the archives.

    - Leigh
    “Wise men talk because they have something to say; fools, because they have to say something.” - Plato

  3. #13

    Join Date
    Jul 2010
    Location
    Southern USA
    Shooter
    Multi Format
    Posts
    3,833
    For more than 20 years I have used a stop bath only for FB papers. Film and RC papers are given a water rinse. Never had any problems even with high alkalinity developers such as Rodinal..
    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. #14
    MattKing's Avatar
    Join Date
    Apr 2005
    Location
    Delta, British Columbia, Canada
    Shooter
    Multi Format
    Posts
    12,382
    Images
    60
    To rephrase Michael's question slightly ...

    If one dilutes Kodak Indicator Stop Bath more than recommended, does the indicator continue to be a reliable test for appropriate activity - i.e. is the stop bath still good if it hasn't turned blue?
    Matt

    “Photography is a complex and fluid medium, and its many factors are not applied in simple sequence. Rather, the process may be likened to the art of the juggler in keeping many balls in the air at one time!”

    Ansel Adams, from the introduction to The Negative - The New Ansel Adams Photography Series / Book 2

  5. #15

    Join Date
    Jul 2010
    Location
    Southern USA
    Shooter
    Multi Format
    Posts
    3,833
    Quote Originally Posted by MattKing View Post
    To rephrase Michael's question slightly ...

    If one dilutes Kodak Indicator Stop Bath more than recommended, does the indicator continue to be a reliable test for appropriate activity - i.e. is the stop bath still good if it hasn't turned blue?
    Yes but its capacity is less.

    I consider indicator stop bath sort of a ripoff as plain acetic acid has its own indicator that is its smell. Sodium acetate has little or no smell. So if you can't easily smell the stopbath then it is time to replace it. However, stop bath should not be saved between printing sessions. By not using an indicator stop bath we keep one more dyestuff out of the environment!

    The indicator used in stop baths is bromcresol purple. It is yellow below a pH of 5.2 and purple at a pH of 6.8. It doesn't work all that well since the stop bath has really lost its effectiveness as soon as the yellow color begins to darken. If you wait for it to turn purple then it really has been exhausted for some time.

    Not all white vinegar is 5%. You really need to check the label as some are only 4%.
    Last edited by Gerald C Koch; 08-06-2012 at 12:12 AM. Click to view previous post history.
    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. #16

    Join Date
    Oct 2011
    Location
    Shanghai, China
    Shooter
    Multi Format
    Posts
    1,948
    Images
    38
    Stupid question from a noob here. Is wearing gloves while developing film a problem? I hear people here talking about dipping their bare hands in chemicals. Why not wear nitrile gloves or something similar?

  7. #17
    MattKing's Avatar
    Join Date
    Apr 2005
    Location
    Delta, British Columbia, Canada
    Shooter
    Multi Format
    Posts
    12,382
    Images
    60
    Quote Originally Posted by RattyMouse View Post
    Stupid question from a noob here. Is wearing gloves while developing film a problem? I hear people here talking about dipping their bare hands in chemicals. Why not wear nitrile gloves or something similar?
    Wearing gloves is a really good idea.

    I almost never wear them, and I have been developing black and white film for 45+ years.

    Yes, those two sentences don't fit well together logically.

    I do, however, have running water at hand at all times when developing film.
    Matt

    “Photography is a complex and fluid medium, and its many factors are not applied in simple sequence. Rather, the process may be likened to the art of the juggler in keeping many balls in the air at one time!”

    Ansel Adams, from the introduction to The Negative - The New Ansel Adams Photography Series / Book 2

  8. #18
    MattKing's Avatar
    Join Date
    Apr 2005
    Location
    Delta, British Columbia, Canada
    Shooter
    Multi Format
    Posts
    12,382
    Images
    60
    I asked my question, because I'm often developing just one or two rolls of film, which in the normal course of events would not come close to exhausting the capacity of something like 600 ml of stop bath.

    I always use stop bath at recommended dilution for paper.
    Matt

    “Photography is a complex and fluid medium, and its many factors are not applied in simple sequence. Rather, the process may be likened to the art of the juggler in keeping many balls in the air at one time!”

    Ansel Adams, from the introduction to The Negative - The New Ansel Adams Photography Series / Book 2

  9. #19

    Join Date
    Jan 2005
    Location
    Western Canada
    Shooter
    Multi Format
    Posts
    426
    For film I have used only a water rinse or bath for film - anything from 35mm to 8x10 film. Never had any problems over the last 45 years.
    For paper I use the Kodak Indicator Stop Bath at 16ml/L. Again no problems with that mixture %.

    Gord

  10. #20

    Join Date
    Feb 2010
    Location
    Montreal, Canada
    Shooter
    Multi Format
    Posts
    4,731
    Quote Originally Posted by Gerald C Koch View Post
    The indicator used in stop baths is bromcresol purple. It is yellow below a pH of 5.2 and purple at a pH of 6.8. .
    Gerald, I equate total acidity to capacity. Is this reasonable? On the other hand the effect of dilution on pH is less clear to me. If the pH of a freshly mixed stop bath is 2.8, how does diluting it affect pH? If you mix Kodak Indicator SB to half strength, it's still yellow - although it is obviously a less intense yellow. The yellow color suggests the pH is still acidic enough to be effective (although with reduced capacity), but is that true?

    Sorry if I'm repeating Matt's question but I want to be clear on the impact on pH, not just capacity. I'm asking because if diluting Kodak SB can get you to a pH of around 4 it should work ok with Pyro and/or carbonate developers.

    This is really only an issue with Pyro where using a water rinse in place of an acidic stop bath may or may not be a problem. With non-staining carbonate developers I'd simply use a water rinse.

Page 2 of 4 FirstFirst 1234 LastLast


 

APUG PARTNERS EQUALLY FUNDING OUR COMMUNITY:



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