Info on dry plates please

Discussion in 'Plate Cameras and Accessories' started by Schlapp, Apr 7, 2006.

  1. Schlapp

    Schlapp Member

    Messages:
    740
    Joined:
    Nov 18, 2004
    Location:
    Isle of Lewi
    Shooter:
    Medium Format
    I have an assortment of unexposed dry plates and would welcome some info on them please - such as what to rate them as.
    Kodak Ortho Rapid
    Eisenberger Reform Platten
    Imperial Eclipse

    The last one has some developer recipes on the box;
    "MQ formula"
    Metol
    Hydrokinone
    Sod. Sulphite
    Sod. Carbonate
    Potassium Bromide
    + water
    develop for 4 mins !

    Anyone know of a current eqiv. ?
    Another one for "Pyro-Soda"
     
  2. Donald Qualls

    Donald Qualls Member

    Messages:
    1,845
    Joined:
    Jan 19, 2005
    Location:
    North Caroli
    Shooter:
    Multi Format
    The "MQ Formula" that you have there is the same ingredients as Dektol. You could find the D-72 formula (try DigitalTruth's technical information page) and compare the two, and likely find your Dektol will do that job. That time is very close to what my 1950s vintage packets of Kodak MQ Universal developer call out for plates.

    Pyro-Soda was a common developer in the pre-D-76 era, though it fell out of favor due to grain when smaller formats made solvent developers like D-76 more preferred; it's the simplest pyro formula, and should give similar results to ABC Pyro (aka Kodak D-1) or PMK.

    All the others will likely share the same process time; B&W films and plates were made to use the same process times across brands and types for decades before color stole the market and relegated B&W to "art" photography.

    For speeds. Hmm.

    Kodak Ortho Rapid is probably ISO 50 equivalent, though it might be one stop faster (but no telling how much speed it's lost in the 50-80 years since it was made). For the others, you're on your own. Maybe you can do a test strip by withdrawing the dark slide a bit at a time and making multiple exposures (to avoid burning all your plates with bracketing or text exposures)?
     
  3. Schlapp

    Schlapp Member

    Messages:
    740
    Joined:
    Nov 18, 2004
    Location:
    Isle of Lewi
    Shooter:
    Medium Format
    Last edited by a moderator: Apr 10, 2006
  4. Donald Qualls

    Donald Qualls Member

    Messages:
    1,845
    Joined:
    Jan 19, 2005
    Location:
    North Caroli
    Shooter:
    Multi Format
    Nice! I see you have the obligatory light leak in the plate holder (I've got fifteen holders for my Ideal, and I think 8 or 9 of them leak under at least some conditions -- eventually I'll figure out *which* 8 or 9). Other than that, it looks pretty good! Rated at 3; that implies it's lost at least two stops, probably more like three or four (original ASA 12 or 25, x2 for the 1960 change in testing method to give 25 or 50), which isn't far out of line for an emulsion that's at least fifty, and possibly up to 80 years old.

    You'd most likely pick up half a stop to a full stop in Dektol compared to Rodinal, if that matters to you...