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  1. #1

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    Film base and resolving power

    Hi,

    I've just developed my very first Delta 400 film (120). I souped it together with TMY-2 in Thornton's 2-bath for 2*5.5 minutes. I've noticed something weird.
    The base density of TMY-2 and Delta 400 looks the same to me, however, when I see through the clear part, the films look very different. The TMY-2 base is almost clear, but the Delta 400 base gives very soft looking objects. It is like looking at the trees in the mist. I didn't print it nor scan it yet, and I'm wondering: is it normal for Delta 400? Does it affect the resolving power? Or maybe my developer is not a good match for it?

    JaZ

  2. #2

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    Is the emulsion side of the film closest to your eye or are you looking through the base at the emulsion?
    Last edited by Gerald C Koch; 02-20-2013 at 10:48 AM. Click to view previous post history.
    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

  3. #3

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    It is the same both ways.

  4. #4
    Mustafa Umut Sarac's Avatar
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    I am sorry but I could not understand what you mean with soft looking objects ? I read that Delta have 4 density at black side of negative but Kodak have 3 or so. I suspect that increased density may be effect the clear part of the negative. May be you are lucky , if you have details at your clearest part of the negative , you have details. But I really dont know. Delta is extremelly interesting film and its creates degrades where we see ultra cleaned , tamed with photoshop , fashion pictures. Its ultra high contrast film to my eye. I want 100 or 200 asa , I could not remember now but I saw similar pictures only at PN55 Polaroid African American portraits. Excellent. Skin shines and its look like wet.

  5. #5

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    When film is printed the light passes first through the base and then the emulsion. Therefore the base has no effect on resolution.

    A developer can have no effect on the film base since it is just plastic. Some films have used a silver halide antihalation layer on the back of the film. With such films inadequate fixing might cause some perceived cloudiness. Howewver I doubt either of the films you mention use this technique.
    Last edited by Gerald C Koch; 02-20-2013 at 12:06 PM. Click to view previous post history.
    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. #6

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    Quote Originally Posted by JaZ99 View Post
    Does it affect the resolving power? Or maybe my developer is not a good match for it?
    I suppose if you put the negative in the enlarger upside down (emulsion side up), the film base could affect the resolution. But as the emulsion is the last thing the light from the enlarger goes through (and the thing you focus on) the film base wouldn't normally affect resolution, only lower the contrast. So a 'heavier' film base would only diffuse the light but not make the image less sharp, assuming the distinction that contrast and sharpness are two different things.

    Steve
    http://www.flickr.com/photos/steve_barnett/

    book
    wood, water, rock,
    landscape photographs in and around the Peak District National Park, UK.

  7. #7
    Mustafa Umut Sarac's Avatar
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    When film is printed the light passes first through the base and then the emulsion. Therefore the base has no effect on resolution.
    I think even an clear base must have an effect on resolution. Basic check at optical resolution / wikipedia article, refractive index of clear base is important. I bet abbe number is important at more detailed analysis. Short answer , every clear base have an MTF graph and Phase graph for each material selection. And surface correctness and the internal morphology resulting from stretch or heat difference will effect the result also.

    If Gerald , I follow your path , if the light passes the base first , base will create a aberration phase for the light. It will than meet with the emulsion and lens and to be needed to be summed.

    Umut

  8. #8
    Newt_on_Swings's Avatar
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    Film base and resolving power

    A clear base just allows for faster printing times. Tmax 100 in 120 is practically clear. Colored bases such as with color neg films will act like a safe light. And staining developers will also give a bit of this safe light effect to some areas such as sky's. Also i you are printing on vs or graded would also make a difference. I think Barry's diaxtol is a type of staining developer. I'll have to check in his book the edge of darkness.

  9. #9
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    The base cannot induce a reduction in resolution.

    It might induce some minor distortion, if it is significantly flawed.

    It can, however, change the appearance of the negative when it is viewed with the naked eye.
    Matt

    “Photography is a complex and fluid medium, and its many factors are not applied in simple sequence. Rather, the process may be likened to the art of the juggler in keeping many balls in the air at one time!”

    Ansel Adams, from the introduction to The Negative - The New Ansel Adams Photography Series / Book 2

  10. #10

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    Quote Originally Posted by Newt_on_Swings View Post
    Colored bases such as with color neg films will act like a safe light.
    Its a bit off topic and I have no intention to nit pick what the OP has said but could someone who knows please clarify for me once and for all if colour neg film base is in any way coloured? It is often claimed, in many different places, to be so but I've always understood the "base" colour to be residual couplers that are themselves coloured and therefore colour neg is coated on ordinary clear base. OzJohn

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