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  1. #11
    Ian Grant's Avatar
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    Quote Originally Posted by Michael R 1974 View Post
    Hey, how come you get away with this correct statement but every time I say it the Rodinal Defence Force comes after me Not fair!
    Because we had High Acutance developers here in Europe that were never commercially available in the US

    Kodak sold HDD, High Definition Developer, Ilford Hyfin, Paterson Acutol S etc. All gave very high acutance but were quite grainy with 35mm films.

    Kodak even sold Kodinol their Rodinal clone in Europe, and Ilford introduced theirs Certinal in 1908 Mees had worked on Rodinal type developers in the early 1900's at Wrateen & Wainwright before Kodak bought the company.

    So having used Hyfin and Acutol S the results with Rodinal are mild in comparison and a better all round blance.

    Ian

  2. #12

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    Photographers Formulary's TFX-2 used in a reduced agitation scheme (2 inversions every 3 minutes) will do the job, too. It gives slightly increased film speed and markedly enhanced edge effects and as a result boosts micro-contrasts. Pretty amazing stuff. The downside is that it is a little expensive and has a 6-month shelf life once you open the bottle.

    Peter Gomena

  3. #13
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    Rodinal difference vs custom developer on HP5+

    The custom developer produced lower negative constrast (you would use higher grade in printing etc), but higher local contrast.


    U1_v_Rodinal by athiril, on Flickr

  4. #14

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    Quote Originally Posted by Jed Freudenthal View Post
    You are right, a high acutance developer will increase the micro-contrast, using the edge effect. This will give a higher perceived sharpness. However, it will degrade the image quality. In 35 mm you really need the increase in micro-contrast
    That's exactly how I understand the situation.

    Quote Originally Posted by Jed Freudenthal View Post
    In 35 mm you really need the increase in micro-contrast, using the edge effect.
    On this last statement, I disagree: a strong edge effect (as provided by high-diluted rodinal) may be disturbing, at least for me, specially with large prints. (that's why, in my opinion, the rendition of some nude photographs by Ralph Gibson looks better in printed books than original silver-prints).

    I like PC-TEA very much because there is not edge effect at all, but it's also true that perceived sharpness with this developer is not always very impressive.

  5. #15

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    The term microcontrast is used in discussing lens resolution and digital images. Can someone provide a link to a scienfific definition as to its use in analog film processing.

    I remain sceptical as to what the OP wants consideriing the films he uses.
    A rock pile ceases to be a rock pile the moment a single man contemplates it, bearing within him the image of a cathedral.

    ~Antoine de Saint-Exupery

  6. #16
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    Quote Originally Posted by Gerald C Koch View Post
    The term microcontrast is used in discussing lens resolution and digital images. Can someone provide a link to a scienfific definition as to its use in analog film processing.

    I remain sceptical as to what the OP wants consideriing the films he uses.
    Here are examples of a fine line simulation with one developer considering a line in 4x5, 120 and 35mm formats. It is from the work of Kriss.

    You will note that in this film/developer combination, as the line gets finer, the contrast goes up.

    PE
    Attached Thumbnails Attached Thumbnails Edge Effects.jpg   Micro Contrast.jpg  

  7. #17

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    Quote Originally Posted by Photo Engineer View Post
    You will note that in this film/developer combination, as the line gets finer, the contrast goes up.

    PE
    Interesting the graph behaves just like the Dirac Delta function. As the interval along the x-axis (the line width) becomes smaller the apex of the distribution (density) becomes higher.
    A rock pile ceases to be a rock pile the moment a single man contemplates it, bearing within him the image of a cathedral.

    ~Antoine de Saint-Exupery

  8. #18
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    Jerry;

    Sometime we MUST talk about this.

    I do hope that we can meet or talk (or both) someday!

    PE

  9. #19

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    Quote Originally Posted by Harold33 View Post
    That's exactly how I understand the situation.



    On this last statement, I disagree: a strong edge effect (as provided by high-diluted rodinal) may be disturbing, at least for me, specially with large prints. (that's why, in my opinion, the rendition of some nude photographs by Ralph Gibson looks better in printed books than original silver-prints).

    I like PC-TEA very much because there is not edge effect at all, but it's also true that perceived sharpness with this developer is not always very impressive.
    I do not mean that you need a strong edge effect with 35 mm. I mean: you need some edge effect. My approach is to start with a minimum edge effect ( a non distorting High Definition developer). And then I imodify the development if I need some edge effect. And, you have to realize that the amount of edge effect is not just determined by the film and developer. It depends also on the quality of the lenses. If you have an optical systerm that is good in rendering the details ( high MTF in the high spatial frequencies), you better avoid the edge effects. Many modern lenses are quite good in rendering details. Then, one has to becareful with the edge effect.
    In a recent APUG meeting we could compare prints from Rodinal and pyrocat HD on medium format. I cetainly prefer the Rodinal. The edge effects were in the Rodinal better (less) than in de pyrocat HD. My personal preference for 4x5"however, is a developer with real low edge effects. A real HD developer ( low distortion in the high spatial frquencies).

    Jed

  10. #20

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    Quote Originally Posted by Gerald C Koch View Post
    The term microcontrast is used in discussing lens resolution and digital images. Can someone provide a link to a scienfific definition as to its use in analog film processing.

    I remain sceptical as to what the OP wants consideriing the films he uses.
    It's just local contrast on a small scale. Tonal boundaries. I doubt a rigourous definition exists, although it can be shown the density difference (contrast) between adjacent tones increases as scale (width, frequency or whatever else people call it) decreases, driven by edge effects.

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