It's the other way around, isn't it?

Discussion in 'B&W: Film, Paper, Chemistry' started by Fred Aspen, Mar 22, 2009.

  1. Fred Aspen

    Fred Aspen Member

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    Excerpt from the User Guide from Digital Truth:

    "Most of these times are for condenser enlargers, so if you are using a diffused light source it is advisable to develop for additional time."

    Just about every time I cross reference developing times to another source, they are virtually always times for diffusion enlargers. I know all Kodak's and Ilford's recommended times on film/developer data sheets are based on diffusion machines. Agfa's recommended times are for a contrast index of 0.65, hefty even for a diffusion machine. Kodak's times are for CI 0.58 for diffusion enlargers. Kodak recommends reducing developing times by 20-30% for condenser enlargers.

    Seems we recommend this chart as the 'Gold Standard' for starting times.

    I have yet to pull a time from the DT Index that has correlated with a condenser enlarger's (CI 0.42-0.43) recommended times.

    What gives? Am I missing something here? Maybe this is why we have so many threads about 'overdeveloped/blocked highlight' film?

    -F.
     
    Last edited by a moderator: Mar 22, 2009
  2. Ian Grant

    Ian Grant Subscriber

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    That's the correct way round, some condenser enlargers were more contrasty, so when diffuser enlargers became more common longer times were recommended to increase the negative contrast.

    Parts of the chart are good other times are way out so treat it with care

    Ian
     
  3. Fred Aspen

    Fred Aspen Member

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    No kidding, Ian, I have been burned several times. I finally learned to cross check before dipping important film.

    More importantly, it's better to be settled on one film/one developer, then problems don't arise.

    I think I read something about that somewhere.

    -F.
     
  4. Anscojohn

    Anscojohn Subscriber

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    Hi Fred,
    What kind of a light source has your enlarger? It is my understanding "condensor" enlargers nowadays are semi-diffuse, starting with an opal bulb, then going through condensors.
     
  5. Ian Grant

    Ian Grant Subscriber

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    Have to agree there's little difference between my old M601 with condensers and an opal bul and the smae enlarger with the CLS66 Colour head & mixing box.

    Both are diffuse compared the the much older condenser types made by a wide variety of companies.

    Ian
     
  6. Fred Aspen

    Fred Aspen Member

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    Ansco,

    I have both; it depends on subject matter which choice I make. If I go with the condenser, I reduce development by 25%. Both condensers are condenser/diffusion machines, one a clear bulb with opal glass, the other an opal bulb.

    With the 25% reduction (from DT recommendations), I get the prints I like with the 2.5/3.0 filter for 35mm negs; I get seriously sharper negs with much less grain with the reduced development. I usually print the 120 negs on the diffusion machine, where it is not as critical.

    -F.
     
  7. George Collier

    George Collier Member

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    Another variable in today's "diffusion" - (I like the term "Cold Light") enlargers is the color of the light and its effect on VC filters/papers. The Aristo light of 20 - 30 years ago was blue-white and gave very high contrast with VC papers. Today's V54 lamp is more greenish and compatible with VC materials, but I still find filter grade 1 - 1.5 normal with negs from decades past that printed well on Seagull G2.
    Then there are color heads, which I've never used.
    Maybe we have too many variables today to make any kind of "condensor vs diffusion" comparisons?