Switch to English Language Passer en langue française Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 68,668   Posts: 1,481,742   Online: 847
      
Page 1 of 2 12 LastLast
Results 1 to 10 of 16
  1. #1
    Ian Grant's Avatar
    Join Date
    Aug 2004
    Location
    West Midlands, UK, and Turkey
    Shooter
    Multi Format
    Posts
    15,939
    Images
    148

    Microdol/Microdol-X Differences

    What are the essential differences between these two Kodak developers ?

    Ian

  2. #2

    Join Date
    Feb 2006
    Location
    Hawaii
    Shooter
    35mm RF
    Posts
    675
    Salt?

  3. #3
    Ian Grant's Avatar
    Join Date
    Aug 2004
    Location
    West Midlands, UK, and Turkey
    Shooter
    Multi Format
    Posts
    15,939
    Images
    148
    Salt instead of what ?

    I'm well aware that Microdol-X and Perceptol use Sodium Chloride in quite significant qualities. Ilford wrote about using Ammonium Chloride in developers back in the mid 60's.

    Ian
    Last edited by Ian Grant; 06-10-2008 at 01:49 AM. Click to view previous post history.

  4. #4

    Join Date
    Nov 2004
    Shooter
    Multi Format
    Posts
    2,048
    A&T in "The FDC" say that MX has the addition of a "weak anti-silvering agent". Benzophenone is their guess.

    Apparently, salt was already in the original Microdol.

    Perhaps only your local PE knows for sure.

  5. #5
    Ian Grant's Avatar
    Join Date
    Aug 2004
    Location
    West Midlands, UK, and Turkey
    Shooter
    Multi Format
    Posts
    15,939
    Images
    148
    Jim, what about Microdol. The literature I've seen in the past always said Microdol-X was silver solvent free, and because the silver solvent in Microdol caused dichroic fog with modern films.

    The reason for asking is that in 1961 Kodak UK released Microdol stating that it was a Silver solvent replacement for DK-20 which of course contained Thiocyanate as the Silver solvent.

    Ian

  6. #6
    df cardwell's Avatar
    Join Date
    Jul 2005
    Location
    Dearborn,Michigan & Cape Breton Island
    Shooter
    Multi Format
    Posts
    3,342
    Images
    8
    IIRC, the addition of thiocyanates and chlorides was not the only choice, that raising the amount of sulfite would have provided similar solvent properties. But it was desirable to keep the pH low, and adding the salt was the better choice.

    In the '30s, '40s, and '50s ( as seen in Lowe's commentary on his developers like E-12 and E-20 ) it was understood that individual testing was necessary to find the right amount of thiocyanate to add to a developer, changing it from a FINE GRAIN developer to a VERY VERY VERY FINE GRAIN developer... without causing fog.

    This was easy for the APUGGER Crafty types of the day, but not so easy for 'off the shelf users', so Kodak replaced their DK-20 (similar to D76+thiocyanate) with D-25 (D-23, but working very slowly to maximize the solvent action of the sulfite). When it was shown to cause dichroic fog in some EK film, Microdol (D-25 + NaCl) was born. It was tweaked again to make Microdol-X. Troop speculates as to what was done. Troop also suggests D-25 has been more successful in some cases than Microdol X. (Oops, Jim has been here already... yes, what HE said !)

    Different film/developer combinations may or may not cause dichro fog. And a developer that caused Dichro fog in the last generation of film might NOT have a problem with the current generation.

    While it is advantageous for Kodak and Ilford to compound developers which cause no problems for their current films, it is not much trouble for us to test the thiocynate method. What is to be gained over Microdol X ? Full film speed for one, higher acutance, AND finer grain.
    "One of the painful things about our time is that those who feel certainty are stupid,
    and those with any imagination and understanding are filled with doubt and indecision"

    -Bertrand Russell

  7. #7

    Join Date
    Nov 2004
    Shooter
    Multi Format
    Posts
    2,048
    Quote Originally Posted by Ian Grant View Post
    Jim, what about Microdol. The literature I've seen in the past always said Microdol-X was silver solvent free, and because the silver solvent in Microdol caused dichroic fog with modern films.

    The reason for asking is that in 1961 Kodak UK released Microdol stating that it was a Silver solvent replacement for DK-20 which of course contained Thiocyanate as the Silver solvent.

    Ian
    Ian, maybe I'm reading between the lines a bit, but here's the quote from the book: "...it consists of D-23 with the startingly simple addition of a small amount of salt. "This is the 'homey' secret behind Microdol and Microdol-X".

    I'm seeing that salt was in Microdol to begin with???

  8. #8

    Join Date
    Jun 2005
    Location
    Plymouth. UK.
    Shooter
    Multi Format
    Posts
    1,399
    Images
    3
    Quote Originally Posted by Ian Grant View Post
    What are the essential differences between these two Kodak developers ?

    Ian
    Ian, P.E might be able to help with this in more detail, but you can search the MSDS from Kodak`s site which might be of some use.
    Microdol-X is rumoured to include an anti-stain agent which helps to prevent dichroic fog. http://www.kodak.com/eknec/PageQueri...requestid=9180

    Also, visit `Google-Patents` and type `Fine-Grain Developers` into the search box.

  9. #9

    Join Date
    Mar 2004
    Location
    Southern California
    Shooter
    Multi Format
    Posts
    3,879
    Images
    11
    Keith, FYI: bis(4-hydroxy-N-methylanilinium) sulphate (from the Microdol-X MSDS) is a synonym for Metol
    Tom Hoskinson
    ______________________________

    Everything is analog - even digital :D

  10. #10
    Ian Grant's Avatar
    Join Date
    Aug 2004
    Location
    West Midlands, UK, and Turkey
    Shooter
    Multi Format
    Posts
    15,939
    Images
    148
    Keith, I've read the relevant Patents, plus more data that's not online. I'm intrigued by what was in the 1961 press releases for Microdol and then the reformulation again to Microdol-X. Not all Kodak materials were identical in the US/UK or even Canada for that matter, similar in a way to the German Agfa and the US Agfa-Ansco products.

    Tri-X differed depending on which country it was manufactured, and data was published for US/UK/Canadian films3, they behaved slightly differently.

    Ian

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