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  1. #11
    David A. Goldfarb's Avatar
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    Quote Originally Posted by RalphLambrecht View Post
    That's possibly the only misinformation AA ever distributed. There is no difference in tonality or gradation between both types of enlarger if the negative was developed accordingly. Yes, a condenser will block the hightlights in a negative developed for a diffuser, but not if the negative was developed for the condenser.
    I'm inclined to agree with that in general, and I believe that Adams acknowledged that you could just develop to lower contrast for condensers as opposed to cold light, but I do wonder about how the Callier effect causes detail to be rendered differently in dense portions of the negative as opposed to light areas. I've never tried to test this definitively, but to answer the question I think it would be necessary, say, photograph a series of resolution charts on a Zone board or something like that, so some of them are in Zone I and some at Zone X and at all steps in between, and then process one neg for a condenser enlarger and one neg for a diffusion enlarger, make prints at the same contrast, and then compare resolution in light and dense areas of the neg on both prints, and compare the prints to each other. Of course the difference in the way diffusion renders grain compared with a condenser enlarger probably makes more of a difference in resolution than the Callier effect.
    flickr--http://www.flickr.com/photos/davidagoldfarb/
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  2. #12
    RalphLambrecht's Avatar
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    Quote Originally Posted by David A. Goldfarb View Post
    I'm inclined to agree with that in general, and I believe that Adams acknowledged that you could just develop to lower contrast for condensers as opposed to cold light, but I do wonder about how the Callier effect causes detail to be rendered differently in dense portions of the negative as opposed to light areas. I've never tried to test this definitively, but to answer the question I think it would be necessary, say, photograph a series of resolution charts on a Zone board or something like that, so some of them are in Zone I and some at Zone X and at all steps in between, and then process one neg for a condenser enlarger and one neg for a diffusion enlarger, make prints at the same contrast, and then compare resolution in light and dense areas of the neg on both prints, and compare the prints to each other. Of course the difference in the way diffusion renders grain compared with a condenser enlarger probably makes more of a difference in resolution than the Callier effect.
    David

    Dr. Richard Henry did that for his book 'Controls in Black and White Photography', and I repeated it with more modern materials. I got the same results as he did; no difference between diffuser and condenser enlarger as long as the negative is developed accordingly.
    Attached Thumbnails Attached Thumbnails TonalDifference.jpg   TonalMatching.jpg  
    Regards

    Ralph W. Lambrecht
    www.darkroomagic.comrorrlambrec@ymail.com[/URL]
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  3. #13
    David A. Goldfarb's Avatar
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    Actually, that shows something different from what I'm thinking about. Your graph shows that you can match print densities by developing the negative accordingly, and I don't dispute that, but I'm asking whether the sharpness of highlights is different due to the light scatter in areas of higher density of the neg and the way they are rendered using a condenser enlarger as opposed to a diffusion enlarger. Of course if the contrast is matched, the highlights need to be even more dense for a diffusion light source, and beyond that diffusion light sources are all about light scatter, but maybe a more precise question would be: is the difference in sharpness between highlights and shadows for prints made with a condenser enlarger different from the difference in sharpness between highlights and shadows for prints made with a diffusion enlarger.

    It's kind of an academic question, because I don't think this is a thing that anyone tries to control in practice, but an answer might add to what we generally understand about the difference in the way prints made using a condenser light source look when compared with prints made with a cold light head.
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  4. #14
    RalphLambrecht's Avatar
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    Quote Originally Posted by David A. Goldfarb View Post
    ...I'm asking whether the sharpness of highlights is different due to the light scatter in areas of higher density of the neg and the way they are rendered using a condenser enlarger as opposed to a diffusion enlarger...
    Condenser enlarger do indeed produce more micro-contrast (apparent sharpness) than diffuser enlargers. Hence, more spotting with condensers. Other than that, no difference. Did I still miss your question?
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    www.darkroomagic.comrorrlambrec@ymail.com[/URL]
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  5. #15

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    Quote Originally Posted by BetterSense View Post
    Also, has anyone ever printed medium format and/or 35mm
    with the 4x5 condensers in place? I understand that they make
    special condensers for smaller formats but I'm having a hard
    time understanding why, considering that if it works for 4x5
    it shouldn't work the same for 35mm, considering 35mm is
    basically a crop out of a 4x5 negative.
    You're instincts are correct. The 4x5 set will cover any
    smaller format and may be expected to do it very well.
    Auxiliary sets for smaller formates are not available
    or an extra with many enlargers.

    Smaller formates need greater enlargement. To keep
    exposure times reasonable the light source is brought
    to a shorter focus. Coverage is reduced while light
    intensity is increased.

    My 'test strips' are full negative very small prints
    printed 2 up on 5x7 paper. On my junior D2, an
    Omega B8, I use a 105mm lens for 6xX. Dan

  6. #16
    David A. Goldfarb's Avatar
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    Quote Originally Posted by RalphLambrecht View Post
    Condenser enlarger do indeed produce more micro-contrast (apparent sharpness) than diffuser enlargers. Hence, more spotting with condensers. Other than that, no difference. Did I still miss your question?
    I'm thinking of something more specific than that, though as I say, it's something of an academic question. Let me try posing it another way. If there is more light scatter in dense areas of the negative than in thin areas of the negative when projected, we might expect highlights on the print to be less sharp than shadows. I'm fairly sure this much is true, because a thinner negative is generally a sharper negative than a denser negative. So my academic question is whether the difference in sharpness between highlights and shadows is more apparent on prints made with a condenser enlarger than with a diffusion enlarger. In other words, is the effect of light scatter in the highlights on sharpness, not print density, greater when the light source is relatively collimated than when it is diffuse.
    flickr--http://www.flickr.com/photos/davidagoldfarb/
    Photography (not as up to date as the flickr site)--http://www.davidagoldfarb.com/photo
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  7. #17
    RalphLambrecht's Avatar
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    Quote Originally Posted by David A. Goldfarb View Post
    I'm thinking of something more specific than that, though as I say, it's something of an academic question. Let me try posing it another way. If there is more light scatter in dense areas of the negative than in thin areas of the negative when projected, we might expect highlights on the print to be less sharp than shadows. I'm fairly sure this much is true, because a thinner negative is generally a sharper negative than a denser negative. So my academic question is whether the difference in sharpness between highlights and shadows is more apparent on prints made with a condenser enlarger than with a diffusion enlarger. In other words, is the effect of light scatter in the highlights on sharpness, not print density, greater when the light source is relatively collimated than when it is diffuse.
    David

    I understand your question, but I need to dig into this a bit deeper. There definitely is a difference between highlight and shadows as far as Callier effect goes, but I have not seen a tonal difference between diffusion and condenser enlargers because of it.
    Regards

    Ralph W. Lambrecht
    www.darkroomagic.comrorrlambrec@ymail.com[/URL]
    www.waybeyondmonochrome.com

  8. #18

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    Ctein has a good evaluation of the differences between condenser, diffusion enlargers in Post Exposure.
    His conclusion was that the differences are more subtle than just contrast, but now I don't remember the details, and I don't know where my copy is hiding.
    Maybe someone who has a copy at hand could elaborate.

  9. #19
    David A. Goldfarb's Avatar
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    I'd forgotten about that chapter in Post Exposure, but yes, he does have some conclusions along these lines.

    One interesting point that he makes is that while a condenser enlarger resolves grain better than a diffusion enlarger, it does not seem to resolve image detail better than a condenser enlarger, image details being larger than individual film grains.

    Ctein observes--

    Quote Originally Posted by Ctein, _Post Exposure_, 2nd ed., p. 70
    Relative to a diffusion head, a condenser head prints the negative highlights with more contrast and the shadows with less, in prints that match in overall contrast. Hence, it is not generally possible to exactly match a condenser print with a diffusion print either by changing paper grade or by changing film processing, although one may get lucky.
    flickr--http://www.flickr.com/photos/davidagoldfarb/
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  10. #20
    RalphLambrecht's Avatar
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    Quote Originally Posted by David A. Goldfarb View Post
    I'd forgotten about that chapter in Post Exposure, but yes, he does have some conclusions along these lines.

    One interesting point that he makes is that while a condenser enlarger resolves grain better than a diffusion enlarger, it does not seem to resolve image detail better than a condenser enlarger, image details being larger than individual film grains.

    Ctein observes--
    That's a conclusion many support.
    Regards

    Ralph W. Lambrecht
    www.darkroomagic.comrorrlambrec@ymail.com[/URL]
    www.waybeyondmonochrome.com

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