Switch to English Language Passer en langue française Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 70,710   Posts: 1,548,627   Online: 1163
      
Page 1 of 2 12 LastLast
Results 1 to 10 of 13
  1. #1
    ParkerSmithPhoto's Avatar
    Join Date
    Jan 2010
    Location
    Atlanta, GA
    Shooter
    Medium Format
    Posts
    823
    Images
    6

    Barry Thornton 2 Bath questions

    Has anyone converted the Barry Thornton two bath higher definition formula to tablespoons or teaspoons? I don't have a gram scale and would prefer not to buy one if it's doable with standard measurements. Most of the scales on Amazon are only accurate to one gram, meaning that the 6.25 grams of metol may just be a ballpark anyway. If in your opinion these amounts are hypercritical and cannot be estimated through teaspoons, etc., please let me know.

    Also, I assume that for Bath A, you mix the metol in first, and then add the sodium sulphite. Is that correct?
    Parker Smith Photography, Inc.
    Atlanta, GA

    Commercial & Fine Art Photography
    Portrait Photography

  2. #2

    Join Date
    Jul 2010
    Location
    Southern USA
    Shooter
    Multi Format
    Posts
    3,866
    The problem with teaspoon measurement is that it depends on the density of the chemical and also its form. A powdered chemical will have a different density than the same chamical in the form of large crystals. Perhaps you could get a friend to measure the weight of known volumes of your chemicals. Then you would be OK until you bought more.
    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

  3. #3
    Alan W's Avatar
    Join Date
    May 2009
    Location
    Tennessee
    Shooter
    Medium Format
    Posts
    370
    Images
    61
    "The metric system is the tool of the devil.My car gets 40 rods to the hogshead"Abe Simpson.

  4. #4
    Stephanie Brim's Avatar
    Join Date
    Jul 2005
    Location
    Iowa
    Shooter
    Multi Format
    Posts
    1,607
    Blog Entries
    1
    Images
    21
    Quote Originally Posted by ParkerSmithPhoto View Post
    Has anyone converted the Barry Thornton two bath higher definition formula to tablespoons or teaspoons? I don't have a gram scale and would prefer not to buy one if it's doable with standard measurements. Most of the scales on Amazon are only accurate to one gram, meaning that the 6.25 grams of metol may just be a ballpark anyway. If in your opinion these amounts are hypercritical and cannot be estimated through teaspoons, etc., please let me know.

    Also, I assume that for Bath A, you mix the metol in first, and then add the sodium sulphite. Is that correct?
    Gram scales of the sensitivity you'd need (probably to the .01g level) are decently cheap. I highly suggest just getting one.
    No idea what's going to happen next, but I'm hoping it involves being wrist deep in chemicals come the weekend.

  5. #5
    David Allen's Avatar
    Join Date
    Nov 2008
    Location
    Berlin
    Shooter
    Med. Format RF
    Posts
    424
    Hi there,

    I bought an electronic jeweler's scale (accurate to 0.1g) for 8€ on e-bay and it was well worth it. Previously I had used mechanical scales and they were a pain. Trying to 'guestimate' with a teaspoon is simply not worth it. Afterall, with Bath B, getting the measurement wrong would affect the final contrast. (With BTTB, the Sodium Metaborate in Bath B can be varied to adjust contrast).

    As to mixing Bath A, you add a pinch of the Sodium Sulphite to the water before adding the Metol and, when fully dissolved, then the rest of the Sodium Sulphite. It helps to have the water pretty hot.

    The simplicity of making BTTB developer and the consistency of the results require that you weigh the chemicals accurately. Therefore, you need to buy a good set of scales. It is a very good investment because mixing your own chemicals will save you so much money and you can 'tweak' your formulae to suit your own needs.

    Best,

    David
    www.dsallen.de

  6. #6

    Join Date
    Feb 2003
    Location
    Jacksonville, FL
    Shooter
    Large Format
    Posts
    1,646
    As to Metol in water, I believe I've seen recommendations of adding a pinch of the sulfite first before adding the Metol.

    As to scales, I picked up quite cheaply a balance-type scale from chemistry classroom. Should be easily found in usual sites.
    van Huyck Photo
    "Progress is only a direction, and it's often the wrong direction"

  7. #7

    Join Date
    Sep 2011
    Location
    Lancaster County, Pennsylvania, USA
    Shooter
    35mm
    Posts
    87
    Also, in Edge of Darkness, he changed the formula slightly to 6.5 g of metol in Bath A. The developer works well and with little fuss but I use longer times than he recommended - about 5.5 to 6 minutes for Bath A and four minutes for Bath B.

  8. #8
    Jim Noel's Avatar
    Join Date
    Mar 2005
    Shooter
    Large Format
    Posts
    1,861
    Blog Entries
    1
    Quote Originally Posted by doughowk View Post
    As to Metol in water, I believe I've seen recommendations of adding a pinch of the sulfite first before adding the Metol.

    As to scales, I picked up quite cheaply a balance-type scale from chemistry classroom. Should be easily found in usual sites.
    You are correct. Eliminate the pinch of sulfite prior to metol and the metol may never go into solution.
    [FONT=Comic Sans MS]Films NOT Dead - Just getting fixed![/FONT]

  9. #9

    Join Date
    Feb 2010
    Location
    Montreal, Canada
    Shooter
    Multi Format
    Posts
    4,775
    That's not the reason. The pinch of sulfite is to help slow down the oxidation of the Metol while it is being dissolved in water. You use a "pinch" because Metol will not dissolve in a solution with a lot of sulfite. So the remainder of the sulfite is added after the Metol is dissolved.

  10. #10
    ParkerSmithPhoto's Avatar
    Join Date
    Jan 2010
    Location
    Atlanta, GA
    Shooter
    Medium Format
    Posts
    823
    Images
    6
    Quote Originally Posted by David Allen View Post
    electronic jeweler's scale
    That's precisely what I needed. $10 on Amazon. Thanks!
    Parker Smith Photography, Inc.
    Atlanta, GA

    Commercial & Fine Art Photography
    Portrait Photography

Page 1 of 2 12 LastLast


 

APUG PARTNERS EQUALLY FUNDING OUR COMMUNITY:



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