Switch to English Language Passer en langue française Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 70,202   Posts: 1,531,555   Online: 1108
      
Page 1 of 3 123 LastLast
Results 1 to 10 of 23
  1. #1
    Martin Aislabie's Avatar
    Join Date
    Nov 2007
    Location
    Stratford-upon-Avon, England
    Shooter
    4x5 Format
    Posts
    1,413

    How much Silver is in a sheet of FB Paper?

    I have been doing a bit of experimenting with toning of Ilford MGFB in Gold Toner

    On the Silverprint Web Site, Martin Reed mentions that a 1L bottle of Gold Toner only contains aprox 0.5g of Gold - which does not sound like much- http://www.silverprint.co.uk/Product....asp?PrGrp=542

    But then, I started to wonder how much Silver is in a single sheet of 10x8 MGFB paper - for comparative purposes to the 0.5G of Gold in the Toner

    Thanks

    Martin

  2. #2
    Marco B's Avatar
    Join Date
    Jan 2005
    Location
    The Netherlands
    Shooter
    Multi Format
    Posts
    2,983
    Images
    169
    See the response by Vaughn in this recent thread, based on that, it should be about 80 mg, based on 1 mg / sq inch:

    http://www.apug.org/forums/forum37/6...n-black-3.html

    Marco
    My website

    "The nineteenth century began by believing that what was reasonable was true, and it wound up by believing that what it saw a photograph of, was true." - William M. Ivins Jr.

    "I don't know, maybe we should disinvent color, and we could just shoot Black & White." - David Burnett in 1978

    "Analog is chemistry + physics, digital is physics + math, which ones did you like most?"

  3. #3
    Photo Engineer's Avatar
    Join Date
    Apr 2005
    Location
    Rochester, NY
    Shooter
    Multi Format
    Posts
    22,972
    Images
    65
    Paper is usually reported in mg/square meter or mg/square foot.

    In my experience, papers run from about 125 mg / square foot to 250 mg / square foot. This agrees reasonably well with the table in Marko's reference. This relates more to a contrast issue than a Dmax issue though, as you can coat quite a range of silver halide and are still limited to a dmax of 2.2 roughly for gloss and about 1.9 for matte paper surfaces, just by the laws of physics.

    I pretty much said that in the other thread. Silver Rich is a myth invented by those that could not get the right contrast except by loading a paper with silver halide to jack up contrast. They had poor emulsions and compensated quantity for quality in a sense.

    PE

  4. #4
    Marco B's Avatar
    Join Date
    Jan 2005
    Location
    The Netherlands
    Shooter
    Multi Format
    Posts
    2,983
    Images
    169
    Quote Originally Posted by Photo Engineer View Post
    This agrees reasonably well with the table in Marko's reference.
    PE, why do you keep consistently writing my name with a "K" instead of "C"...

    Time for a new pair of glasses maybe?

    Marco
    My website

    "The nineteenth century began by believing that what was reasonable was true, and it wound up by believing that what it saw a photograph of, was true." - William M. Ivins Jr.

    "I don't know, maybe we should disinvent color, and we could just shoot Black & White." - David Burnett in 1978

    "Analog is chemistry + physics, digital is physics + math, which ones did you like most?"

  5. #5
    Marco B's Avatar
    Join Date
    Jan 2005
    Location
    The Netherlands
    Shooter
    Multi Format
    Posts
    2,983
    Images
    169
    And now another interesting question is how much gold replaces silver in an 8x10 sheet when toning? E.g. 80 mg silver = 80 mg of gold or NOT???

    Probably we need to do some molarity based chemistry calculation, but does someone have the figures ready?
    My website

    "The nineteenth century began by believing that what was reasonable was true, and it wound up by believing that what it saw a photograph of, was true." - William M. Ivins Jr.

    "I don't know, maybe we should disinvent color, and we could just shoot Black & White." - David Burnett in 1978

    "Analog is chemistry + physics, digital is physics + math, which ones did you like most?"

  6. #6
    Photo Engineer's Avatar
    Join Date
    Apr 2005
    Location
    Rochester, NY
    Shooter
    Multi Format
    Posts
    22,972
    Images
    65
    Quote Originally Posted by Marco B View Post
    PE, why do you keep consistently writing my name with a "K" instead of "C"...

    Time for a new pair of glasses maybe?

    Marco
    Marco;

    Apologies to you for my error. I hope no one ever does it again, myself included.

    PE

  7. #7
    Marco B's Avatar
    Join Date
    Jan 2005
    Location
    The Netherlands
    Shooter
    Multi Format
    Posts
    2,983
    Images
    169
    Quote Originally Posted by Photo Engineer View Post
    Marco;

    Apologies to you for my error. I hope no one ever does it again, myself included.

    PE
    Apologies accepted . It wasn't a big deal at all, but I have seen you writing my name with K in a few other threads as well, so I started wondering :o. Actually, there are Marco's with K in the Netherlands, but C is more common.

    I also started to wonder what substance of gold is created during gold toning. If you want to make a molarity based calculation, assuming all metallic silver is replaced by gold, it will make a difference to the total weight of the final deposit if the gold is not pure gold, but some compound bound with another substance, like for example a sepia toned image where the silver binds with sulphur. Of course, the amount of gold used per sheet is not influenced by that, because that is purely based on the molarity calculation and the ratio of number of silver atoms replaced (or is it supplemented?) by number of gold atoms.

    Does gold toning replace silver, or deposit as a layer on the silver?
    Last edited by Marco B; 04-22-2009 at 01:55 PM. Click to view previous post history.
    My website

    "The nineteenth century began by believing that what was reasonable was true, and it wound up by believing that what it saw a photograph of, was true." - William M. Ivins Jr.

    "I don't know, maybe we should disinvent color, and we could just shoot Black & White." - David Burnett in 1978

    "Analog is chemistry + physics, digital is physics + math, which ones did you like most?"

  8. #8

    Join Date
    Jun 2004
    Location
    Portland, OR
    Shooter
    4x5 Format
    Posts
    3,268
    Does gold toning replace silver, or deposit as a layer on the silver?
    Both, I thought. It's a "noble" metal replacement reaction - the gold plates onto the silve as a thin layer on top, but an equal molar amount of silver is lost to solution. Also, there's thiocyanate in the gold toner, I'm assuming it's acting as a silver solvent to etch/clean the surface of the silver.
    Kirk

    For up from the ashes, up from the ashes, grow the roses of success!

  9. #9
    Photo Engineer's Avatar
    Join Date
    Apr 2005
    Location
    Rochester, NY
    Shooter
    Multi Format
    Posts
    22,972
    Images
    65
    I had always thought that some sulfides formed during Gold toning. Any ideas on that Kirk?

    PE

  10. #10

    Join Date
    Sep 2002
    Location
    Willamette Valley, Oregon
    Shooter
    Medium Format
    Posts
    3,684
    Quote Originally Posted by Marco B View Post
    See the response by Vaughn in this recent thread,
    based on that, it should be about 80 mg, based
    on 1 mg / sq inch: Marco
    That's about it, 0.08 grams per 8x10 or 1.6 grams per
    square meter. That's an average of several papers. Slavich
    claims the least at 1.2 - 1.3 while I've seen another at 2.2
    grams per square meter.

    The specific mix of halides will make a difference when it
    comes to fixing. As expected, after testing 4 papers, Slavich
    takes the least and Kentmere Bromide the most; at least
    half again more.

    If you want warm tones at nearly no per print expense then
    Nelson's Gold Toner is the one to use. As I understand it,
    Nelson's is essentionally a sulfide toner modified in
    color by the the gold's presence. Great for
    archival results. Dan

Page 1 of 3 123 LastLast


 

APUG PARTNERS EQUALLY FUNDING OUR COMMUNITY:



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