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  1. #1

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    The effect of greater dilution on grainsize and contrast?

    Lately I am wondering what the effect is of greater dilution in the developer on the contrast and the size of the grain of your B&W negative.

    I know that a longer developing time gives more contrast and increases the grain size (correct me if I'm wrong), but what about the effects of greater dilution? What happens to the contrasts and to the grain goin from say 1:25 to 1:50 or to 1:100?

    cheers, mike

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    Anscojohn's Avatar
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    Grain size is virtually 100% a function of the level of development, all things being equal. Thus, greater dilution will only decrease apparent grain by decreasing the level of development. the grain will not be decreased if the film is developed to the same density and gamma. That being said, if the grain is sharper because of greater adjacency effects caused by extra dilution, the apparent grain might be subjectively less obtrusive.

    Anscojohn, Mount Vernon, Virginia USA

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    Quote Originally Posted by Anscojohn View Post
    Grain size is virtually 100% a function of the level of development, all things being equal. Thus, greater dilution will only decrease apparent grain by decreasing the level of development. the grain will not be decreased if the film is developed to the same density and gamma. That being said, if the grain is sharper because of greater adjacency effects caused by extra dilution, the apparent grain might be subjectively less obtrusive.

    Anscojohn, Mount Vernon, Virginia USA
    Film grain size is primarily determined by size and structure of the grains placed in the emulsion by the film manufacturer.
    Tom Hoskinson
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    when you start these discussions you should state whether you mean silver grains or grain clumps. For the most part what most people call grain is actually grain clumps. The silver grains migrate into clumps during development. The actual silver grains are minute compared to the grain clump sizes. So what causes clumping? I have no definitive answer to that but I have observed that the higher th PH of the developer, the greater the tendancy of the grain to clump. I know the chemists will argue about this but that is my observation. If grain size is an issue for you, then use Ilford Perceptol or Kodak Microdol X to develop your negatives. You will then have a problem seeing the grain through your grain maginifier because of the lack of clumping that takes place. The grain you see, if you can will be very very fine.
    Use Perceptopl at 1+2 or 1+3 @ 20deg C for appropriate time for your film. About 12mins for HP5 at 1+3. Also Reduce film speed by about 1 stop from iso speed when using either of these developers.
    Percepts,
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  5. #5

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    [QUOTES=percepts;472925]
    "I have observed that the higher th PH of the developer,
    the greater the tendency of the grain to clump."

    I've not checked specifically for that but have read that
    developer ph is second only to the film itself where grain
    size is concerned.

    "Kodak Microdol X to develop your negatives. You will then
    have a problem seeing the grain through your grain magnifier
    because of the lack of clumping that takes place."

    First place does go to Microdol X for least grain while it
    and Perceptol maintained maximum sharpness. The latter
    slipped a bit on grain. Dilution made little to no difference.
    That from an article by Otis Sprow in Darkroom and Creative
    Camera Techniques. Panatomic X and Agfapan 25 were tested.

    Rodinal developed the most grain; as good though as any
    other for sharpness. If I'm not mistaken, Microdol X is a very
    low ph developer with long developing times. Is it available
    off-the-shelf? I home brew; perhaps a formula? Dan

  6. #6
    percepts's Avatar
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    Quote Originally Posted by dancqu View Post
    [QUOTES=percepts;472925]
    If I'm not mistaken, Microdol X is a very
    low ph developer with long developing times. Is it available
    off-the-shelf? I home brew; perhaps a formula? Dan
    Assuming Kodak are still making it, then it should be available off the shelf. I use Perceptol for 35mm film as it is readily available in the UK where as Microdol X is not. For 4x5 I use HC110 which is also readily available in the UK.
    Percepts,
    An old dog learning new tricks...

    Black and White Landscape Prints

  7. #7
    John Bragg's Avatar
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    Greater dilution in combination with less agitation can produce some very smooth results. There is not nescessarily less grain, just that it looks more refined and less clumpy. This is Tri-X (@ EI 200) in HC-110 Dilution H. 9 mins @ 20c. Agitation continuous for first 30 secs, then 2 gentle inversions at the start of each subsequent minute.Contrast is also held in check by the slight compensation at this dilution.

    http://www.rangefinderforum.com/phot...hp?photo=63551

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    Quote Originally Posted by dancqu View Post
    [QUOTES=percepts;472925]
    "I have observed that the higher th PH of the developer,
    the greater the tendency of the grain to clump."

    I've not checked specifically for that but have read that
    developer ph is second only to the film itself where grain
    size is concerned.

    "Kodak Microdol X to develop your negatives. You will then
    have a problem seeing the grain through your grain magnifier
    because of the lack of clumping that takes place."

    First place does go to Microdol X for least grain while it
    and Perceptol maintained maximum sharpness. The latter
    slipped a bit on grain. Dilution made little to no difference.
    That from an article by Otis Sprow in Darkroom and Creative
    Camera Techniques. Panatomic X and Agfapan 25 were tested.

    Rodinal developed the most grain; as good though as any
    other for sharpness. If I'm not mistaken, Microdol X is a very
    low ph developer with long developing times. Is it available
    off-the-shelf? I home brew; perhaps a formula? Dan
    Try this Microdol-X substitute recipe, Dan:


    In 1 liter of water dissolve:
    Metol 5 grams
    Sodium Sulfite (anhydrous) 100 grams
    Sodium Chloride (iodine free) 30 grams
    Tom Hoskinson
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  9. #9
    Anscojohn's Avatar
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    Quote Originally Posted by Tom Hoskinson View Post
    Film grain size is primarily determined by size and structure of the grains placed in the emulsion by the film manufacturer.
    ******
    That's covered by "all things being equal," as a moment's reflection might make more understandable.

    Anscojohn, Mount Vernon, Virginia USA

  10. #10

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    Quote Originally Posted by Tom Hoskinson View Post
    Try this Microdol-X substitute recipe, Dan:

    In 1 liter of water dissolve:
    Metol 5 grams
    Sodium Sulfite (anhydrous) 100 grams
    Sodium Chloride (iodine free) 30 grams
    Included in P. Dignan's Classic B&W Formulas is
    another substitute formula from R. W. Anderson.

    Metol 7.5 grams
    Sodium Sulfite anhydrous 100 grams
    Sodium Bisulfite 7.5 grams
    Water to make 1 liter.

    Almost a D-25. Times and results are the same
    as for Microdol-X. The substitute's weight is not
    the same as the packaged. I doubt that sodium
    chloride will reduce the ph while S. bisulfite
    should some little.

    If one would like to go the ultra-fine grain route via
    low ph and without all that chemistry a bicarbonated
    FX-1 or Beutlers should be worth a try. As with the
    substitutes there likely would be a speed hit. Dan

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