Prints Per Volume Of Chemistry

Discussion in 'The Darkroom' started by Dave Colangelo, Aug 9, 2017.

  1. Derrel

    Derrel Mr. Rain Cloud

    Joined:
    Jul 23, 2009
    Messages:
    40,009
    Likes Received:
    15,006
    Location:
    USA
    Can others edit my Photos:
    Photos OK to edit
    I think a 60-second development time is too short for the ultimate in consistency, even on RC paper. A few seconds here or there, a bit more vigorous agitation of slightl less-viforous agitation, etc..; to me, on a 60-second total development time, the time and the agitation is too short for consistency. When do you start the dveloping timing? As the print hits the developer? After it has been submerged in total? When do you stop the timer? As soon as you lift it out of the Dektol (that's a hint: get some Dektol for Kodak paper, Ilford for Ilford)? Do you count the drain time as part of the development time? If you have no stop bath, the print continues developing a bit....with plain water, after 10,15 prints, the water is not stopping development very much.

    Do you develop prints FACE-DOWN? SO there's no temptation to "yank" the print early?

    Do some experiments; if your darkroom is light-tight AND your safelight is not fogging your paper, I think you might find a slightly richer, deeper D-max black and more contrast between the tones with a 90-second or 100-second or 120-second development time. Yes, even on RC paper. Again: I dislike a 60-second development time for enlargements...I think it leads to substandard work, and makes RC paper prints often look, well..substandard.

    Microwaved hamburger. Pan-friend hamburger.

    Paper developer is far better that film developer, althougnh I will admit, I have souped a fair amount of prints in HC-110 film developer.


     
  2. maris

    maris TPF Noob!

    Joined:
    Mar 3, 2010
    Messages:
    126
    Likes Received:
    16
    Location:
    Noosa, Australia
    I'd suggest both references "Overexposure", and Monona Rossol"s activities as a "industrial hygienist" are not a good guide to actual darkroom hazards. "Overexposure" looks just like it was compiled by cross-referencing of MSDS lists with entries in chemical compendia; all without an understanding of either chemistry or toxicology.

    Monona Rossol has a notoriety as a chemical alarmist and a gun-for-hire in damages claims where chemicals are accused. As a retired scientist with work in both chemistry and toxicology I'd grant her no credibility.

    Doing epidemiology searches on the internet is challenging but I can't find any medically authenticated instances of harm from darkroom chemistry in the last decade. Yes, there is alarmism about "chemicals" together with ignorance, anxiety, and ill-founded anecdotes. But not one case of proven harm.

    The best source of information about the correct usage of darkroom chemistry comes directly from the manufacturer. Ask them. They have a deep and vested interest in keeping you safe.
     
    • Agree Agree x 1
  3. timor

    timor Been spending a lot of time on here!

    Joined:
    Feb 28, 2011
    Messages:
    5,761
    Likes Received:
    839
    Location:
    Toronto ON
    Can others edit my Photos:
    Photos NOT OK to edit
    I use darkroom for the past 40 years. (On and off). Never developed (?!?) any respiratory or over sensitivity problems. Off course I am only an amateur spending only about 6 to 8 hours per week printing. On the other hand Ansel Adams died at 82 and his darkroom time was much longer and much more intense.
     
  4. webestang64

    webestang64 No longer a newbie, moving up!

    Joined:
    May 15, 2013
    Messages:
    971
    Likes Received:
    448
    Location:
    St. Louis, MO. USA
    Can others edit my Photos:
    Photos NOT OK to edit
    I have always had a well vented area for all my darkroom work. At one time period in my photo lab career I was in the darkroom 8 hours a day for 15 years straight. Worst stuff ever was old EP2 chem (one hour lab chem before RA4).......I'm sure that was what gave me asthma later in life.


    Everything you need to know right here about that devoper..... https://www.ilfordphoto.com/amfile/file/download/file_id/1982/product_id/743/
     
  5. timor

    timor Been spending a lot of time on here!

    Joined:
    Feb 28, 2011
    Messages:
    5,761
    Likes Received:
    839
    Location:
    Toronto ON
    Can others edit my Photos:
    Photos NOT OK to edit


    Aaah, colour chemistry, that's different. Much more aggressive...
     

Share This Page