contrast ranges

Discussion in 'Alternative Processes' started by Ray Heath, Mar 17, 2007.

  1. Ray Heath

    Ray Heath Member

    Messages:
    1,020
    Joined:
    Dec 29, 2005
    Location:
    Eastern, Aus
    Shooter:
    Multi Format
    in simple terms of low/medium/high, can someone explain what level of contrast is required for van dyke and cyanotype printing

    thnx
    Ray
     
  2. sanking

    sanking Member

    Messages:
    4,813
    Joined:
    Mar 26, 2003
    Location:
    Greenville,
    Shooter:
    Large Format
    cyanotpe -- medium contrast, or negative with a DR of about 1.5

    vandyke -- very high, negative with a DR of about 2.2.

    Sandy King
     
  3. Ray Heath

    Ray Heath Member

    Messages:
    1,020
    Joined:
    Dec 29, 2005
    Location:
    Eastern, Aus
    Shooter:
    Multi Format
    thnx Sandy, concise and to the point as requested

    a further question, it seems to me that alternative prints often have poor tonality, PD/PTs usually look flat, cyanotypes usually look too harsh

    so, is the poor tonality because the wrong type of negative is used, or are the results just how it is for alternative printing methods?
     
  4. DrPablo

    DrPablo Member

    Messages:
    796
    Joined:
    Aug 16, 2006
    Location:
    North Caroli
    Shooter:
    Multi Format
    Ray, I don't have much experience with this, but in my cyanotyping I invariably get better results with high contrast negatives as long as the contrast isn't extreme. For the extreme contrast negatives, I have been getting good results by grossly overexposing the cyanotype, then either bleaching it with a dunk in a weak alkali (I use household ammonia in water), or brushing the weak alkali over the areas that are too dark using a watercolor brush.
     
  5. Jim Noel

    Jim Noel Member

    Messages:
    2,144
    Joined:
    Mar 6, 2005
    Shooter:
    Large Format
    If the of the negative does not match the process, and some kind of contrast alteration is not used, the print will be either too flat or too contrasty. Bleaching back works, but a proper negative works better and more consistently.
     
  6. Vaughn

    Vaughn Subscriber

    Messages:
    5,305
    Joined:
    Dec 13, 2006
    Location:
    Humboldt Co.
    Shooter:
    8x10 Format
    Silver prints poorly made also can be of poor tonality, flat or harsh. Try to find some alt prints made by those who know what they are doing (the real thing -- not on a computer screen or in a book). Because alt printing has so many variables left up to the artist (as opposed to the relatively straight-forward off-the-shelf silver gelatin process) it takes one a while to control all the variables to produce good work.

    Many experienced silver printers dabble in alt printing, then get turned off by their sub-standard results...forgetting that their first negatives and silver prints were probably not all that hot either.

    Perhaps someone in NSW can point you in a direction of where to find some quality alt prints to see.

    Vaughn
     
  7. Lukas Werth

    Lukas Werth Member

    Messages:
    266
    Joined:
    Oct 26, 2005
    Location:
    Pakistan
    Shooter:
    Multi Format
    Platinum prints neither have the same dmax, nor are their whites so bright as in gelsilver. So if you don't get right, they look flat (as do, in my opinion, quite some historical pt prints, as I recall from a visit in the national portrait gallery in London). However, they excell in the range of tones in between, they are, as other siderotypes (metal salt prints), also cyanotypes, able to produce prints prints from which the light seems to emanate, with what many people associate with the quality of a drawing, soft and beautiful.

    In my view, the contrasty qualities of traditional silverprints many people look for are the result that historically viewers got used to their reduced tonalities.
     
  8. Loris Medici

    Loris Medici Member

    Messages:
    653
    Joined:
    Sep 13, 2005
    Location:
    Istanbul, Tu
    Shooter:
    Multi Format
    Cyanotype with high contrast negatives

    You may try to develop in weak acetic or citric acid. Even put 40% citric acid in the coating solution (start with 1 drop 40% citric acid per 10 drops of coating solution) to get a low contrast emulsion with Cyanotypes. The DR required for my New Cyanotypes is log 2.4 which is on par with Vandyke, Albumen or Salt Prints...

    Regards,
    Loris.