condenser vs. diffusion

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In a recient thread here someone mentioned that with newer films, there shouldn't be much difference in contrast between diffusion and condenser enlargers. In A. Adams book "The Negative" , he states densities for zones V and VIII and they are different for condenser and diffision enlargers. Is that info out of date? I'm in the middle of film testing, and getting ready to shoot some zone V and VIII frames and would like some suggestions on what densities to look for when i have the negs read. My enlarger is a Beseler 23c II condenser. Any other advice/ help is always apprecieated. ( except spelling advise... i know i have a problem there.)

-- dee seegers (deesee@pinn.net), February 23, 2002

Answers

IMHO, the info is not out of date and I'd start with those numbers. Modern films still print differently because they still have grain. I do think a good case can be made for not bothering with the densitometer at all, as what you're really trying to do is match development to your whole printing system- paper, enlarger, etc. If using the density readings improves your comfort factor, than certainly do it, but expect to fine tune the results a bit. Ctein has a good section on condenser vs diffusion in his book Post Exposure (highly recommended). His conclusion was that they do print differently and changing film development and/or paper grade does not result in identical prints. The diffusion enlarger had more open shadow areas and less highlight contrast. Still, I prefer a condenser enlarger because the image is brighter for focusing. Be sure your 23CII has a heat absorbing glass, as it's very prone to negative pop. (email for more on the 23CII)

-- Conrad Hoffman (choffman@rpa.net), February 24, 2002.

For what it's worth, with modern black & white film, I have found about a half grade difference using between condenser and diffusion lamp on the same type enlarger. But the look is different, as Conrad indicated. Personally, I prefer the look of the disfusion for most prints, but it's all a matter of taste and subject matter.

-- Jim Rock (jameswrock@aol.com), February 24, 2002.

Anyone who claims that "with newer films, there shouldn't be much difference in contrast between diffusion and condenser enlargers" is mistaken. Whether or not the film is a “new’ or an “older” emulsion, is irrelevant. For a given (already developed) negative, a condenser enlarger will produce a higher contrast print than a diffusion enlarger, especially in the highlights. This is hard to precisely quantify because not all condenser enlargers are identical and not all diffusion heads are the same. Even the same enlarger can vary depending on the light bulb used, the position of the condensers, how far away the diffuser is placed from the negative, etc.

With any film (newer or older emulsion) the contrast range of the negative can be manipulated by changing the film development time. By changing the film development time, one can largely (but maybe not exactly) offset the inherent contrast differences in enlarger heads. For example, if a condenser enlarger prints 1/2 contrast range higher than diffusion, the film development time can be reduced to produce a negative that has about 1/2 grade lower inherent contrast.

-- Michael Feldman (mfeldman@qwest.net), February 24, 2002.


thanks for all the input and help. i learn something everyday on this site. i've seen ctein mentioned many times before, i'll look for some books. thanks again all. dee

-- d.s. (deesee@pinn.net), February 24, 2002.

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