Exposure strategies for Kallitypes

Discussion in 'Alternative Processes' started by JG Motamedi, Dec 4, 2008.

  1. JG Motamedi

    JG Motamedi Member

    Messages:
    472
    Joined:
    Dec 18, 2004
    Location:
    Portland, OR
    Shooter:
    Large Format
    How do you strategize exposure for Kallitypes? Based on what I know about the action of dichromates on highlights, I have been exposing for the shadows and changing the percentage of dichromate to adjust the highlights. Obviously, this is opposite the received wisdom for printing silver gelatin where one exposes for the highlights and uses graded paper/filters to control contrast.

    I ask because I have recently acquired a Nuarc flip-top platemaker and a densitometer with a UV channel (Craigslist, free for the hauling!). After a few light repairs, I have been amazed at the consistency that the integrator affords. So much more reliable than the fickle sun. However, its reliability has begged new questions, and one of those is how to strategize exposure. I am preparing to start taking advantage of this and use the densitometer, but before I crack out the graph paper, want to hear what others are doing.


    Thanks in advance.
     
  2. sanking

    sanking Restricted Access

    Messages:
    4,813
    Joined:
    Mar 26, 2003
    Location:
    Greenville,
    Shooter:
    Large Format
    You have the correct strategy for kallitype -- expose for the shadows and use dichromate to control contrast. However, as in palladium it is best to use as little dichromate as possible. I generally develop for a negative density range of about 1.8 - 2.0, which should print OK with kallitype using about 2ml of a 5% solution of dichromate per liter of developer.

    Sandy King



     
  3. JG Motamedi

    JG Motamedi Member

    Messages:
    472
    Joined:
    Dec 18, 2004
    Location:
    Portland, OR
    Shooter:
    Large Format
    Thanks Sandy, I am glad to know that I am not completely off track. Aside from apparent graininess in the highlights, and flushing a nasty chemical down the drain, what are the other disadvantages to using too much dichromate?
     
  4. sanking

    sanking Restricted Access

    Messages:
    4,813
    Joined:
    Mar 26, 2003
    Location:
    Greenville,
    Shooter:
    Large Format
    I don't find any disadvantages in the dichromate system of contrast control with kallitype. You will of course have to replenish your developer to get consistent results, and if you use dichromate in the developer you will have to replenish with it as well. Also, I am not sure if the dichromate is stable in the developer but if you replenish on a regular basis and do a fair amount of printing you will be changing over the contents of the developer often. For example, I recommend replenishing with about 100 ml of solution for every 8X10 (or equivalent) print that is developed. With ten prints you completley change over the solution.

    BTW, graininess in the highlights should not be a problem unless you need to use over about 10ml of a 5% solution per liter of developer.

    Sandy King