Switch to English Language Passer en langue française Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 70,328   Posts: 1,537,049   Online: 1043
      
Page 3 of 5 FirstFirst 12345 LastLast
Results 21 to 30 of 42
  1. #21
    cinejerk's Avatar
    Join Date
    Mar 2009
    Location
    Photographer's Formulary Country
    Shooter
    Multi Format
    Posts
    163
    Took me a long time to find the post again but here it is:

    http://www.apug.org/forums/forum37/1...tml#post290483


    scroll down a bit. it's near the bottom

  2. #22
    Ian Grant's Avatar
    Join Date
    Aug 2004
    Location
    West Midlands, UK, and Turkey
    Shooter
    Multi Format
    Posts
    16,253
    Images
    148
    Don't believe everything you read

    It's entirely possible someone uses D76 1+1 for Reversal processing of high contrast films, but that post flies in the face of accumulated wisdom, and all published formulae.

    Ian

  3. #23

    Join Date
    Aug 2005
    Location
    Los Alamos, NM
    Shooter
    Multi Format
    Posts
    2,052
    Quote Originally Posted by cinejerk View Post
    so even if I did buy D19 I would have to adulterate it with KSCN?

    What really blows me away is why in the original posting it shows D76
    diluted?
    Why would you do this if you need a faster acting/stronger developer?
    D-67 is really quite different from D-76. In fact it is D-19 with the addition of 2 grams per liter of potassium thiocyanate. The thiocyanate definitely helps both to produce clear highlights and to increase the shadow density. I've seen a suggested development time of 8 minutes for PXN.

    D-72 is similar to Dektol. That or a similar paper developer could be used as a second developer.

  4. #24
    cinejerk's Avatar
    Join Date
    Mar 2009
    Location
    Photographer's Formulary Country
    Shooter
    Multi Format
    Posts
    163
    The only difference I see between D19 and D76 is 3 grams of hydroquinone and some sodium carb and pot bromide. What does the potassium bromide do to make it a better first developer?

  5. #25
    Ian Grant's Avatar
    Join Date
    Aug 2004
    Location
    West Midlands, UK, and Turkey
    Shooter
    Multi Format
    Posts
    16,253
    Images
    148
    The most critical addition is the carbonate compared to D76 this will make the developer significantly more vigorous and contrasty, the Hydroquinone will help as well. Bromide is left out of some Reversal first developers as you don't want too much restrainer.

    In fact Kodak used to recommend D168 which is identical to D67 (D19 + Thiocyanate) except has no Bromide.

    Ian

  6. #26
    cinejerk's Avatar
    Join Date
    Mar 2009
    Location
    Photographer's Formulary Country
    Shooter
    Multi Format
    Posts
    163
    Thank you very much Ian for sticking with me here. You have been a great help;-)

    As you said in a posting above that 50gm of sodium carb is roughly equivalent to 5gm of sodium hydroxide.

    So I am going to try adding the 5gm of sodium hydroxide and see how it works. What do you think?

    By the way the film that was too dark I'm sure was under exposed also. I need to remedy that also.
    thanks
    Dennis

  7. #27

    Join Date
    Sep 2004
    Location
    Toronto, Canada
    Shooter
    Multi Format
    Posts
    587
    The hydroquinone is also a "contrast-inducing" ingredient IIRC.

  8. #28
    Photo Engineer's Avatar
    Join Date
    Apr 2005
    Location
    Rochester, NY
    Shooter
    Multi Format
    Posts
    22,972
    Images
    65
    The bromide will restrain things, especially with KSCN there. This will keep the reaction from going out of control.

    PE

  9. #29
    dr5chrome's Avatar
    Join Date
    Dec 2006
    Shooter
    Medium Format
    Posts
    445
    Images
    12
    D76 1:1 especially at longer development times will produce a terrific quality image in some film types in reversal processing. The key would be to do some testing. Sticking with published recipes doesn't always render the perfect result.

    It is very possible to modify your D76 if that's what you want to use. PX is a flat film as a positive so with that in mind you'll want to do what you need to do to the D76 or the 1st development to generate some contrast.

    regards
    dw


    Quote Originally Posted by cinejerk View Post
    The only difference I see between D19 and D76 is 3 grams of hydroquinone and some sodium carb and pot bromide. What does the potassium bromide do to make it a better first developer?

  10. #30
    cinejerk's Avatar
    Join Date
    Mar 2009
    Location
    Photographer's Formulary Country
    Shooter
    Multi Format
    Posts
    163
    Thanks dr5chrome for that info. You are the first to say something positive about d76.

    What are your suggestions for increasing contrast?

Page 3 of 5 FirstFirst 12345 LastLast


 

APUG PARTNERS EQUALLY FUNDING OUR COMMUNITY:



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