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  1. #1
    Jeff Bannow's Avatar
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    Test procedure for even development?

    I would like to run a test of my 4x5 sheet film development process, specifically looking for evenness from agitation. Here's my plan:

    1. Find an evenly lit wall in the sunshine and meter for middle gray. Take a picture.
    2. Develop.
    3. Examine and look for any anomalies on the light table.

    This seems so simple, that I must be missing something. Anyone have a preferred method?
    - Jeff (& sometimes Eva, too) - http://www.jeffbannow.com

  2. #2
    Overkill-F2's Avatar
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    Are you tray developing your 4x5's?
    I might expose three sheets, zone 3, 5 and 7, contact print, then examine them.
    ...Terry

  3. #3
    Jeff Bannow's Avatar
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    This will be inversion processing.
    - Jeff (& sometimes Eva, too) - http://www.jeffbannow.com

  4. #4
    wildbill's Avatar
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    Jobo, expert drum.
    www.vinnywalsh.com

    I know what I want but I just don't know how to go about gettin' it.-Hendrix

  5. #5

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    Quote Originally Posted by Jeff Bannow View Post
    I would like to run a test of my 4x5 sheet film development process, specifically looking for evenness from agitation. Here's my plan:
    1. Find an evenly lit wall in the sunshine and meter for middle gray. Take a picture.
    2. Develop.
    3. Examine and look for any anomalies on the light table.
    This seems so simple, that I must be missing something. Anyone have a preferred method?
    Illumination of lenses tend to fall off near the edges and corners. Perhaps expose the film using the enlarger at f/16 instead? Or put the film on the counter and blink a light in the darkroom?
    Also, the human visual system has a hard time seeing gradual changes in luminance. I suggest using a densitomer, or placing a light meter in various places on the film to measure densities.

    Mark Overton

  6. #6
    Jeff Bannow's Avatar
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    Quote Originally Posted by wildbill View Post
    Jobo, expert drum.
    Sold my Jobo, Vinny.
    - Jeff (& sometimes Eva, too) - http://www.jeffbannow.com

  7. #7

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    Use your enlarger - assuming it illuminates evenly. Raise the head way up and stop down so there's no falloff. Expose a sheet of film to some mid-tone density. Process it. And then contact print it.

    What kind of tank/system are you using for inversion?

  8. #8
    Jeff Bannow's Avatar
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    Quote Originally Posted by Michael R 1974 View Post
    The best way to do it is use your enlarger - assuming it illuminates evenly. You raise the head way up and stop down so there's no falloff. Expose a sheet of film to some mid-tone density. Process it. And then contact print it.
    Interesting - I've never exposed film via my enlarger before actually.

    So:

    Turn off safelight.
    Get the enlarger head to a point with even illumination and stop down lens.
    Use incident meter to make exposure in the multiple second range.

    I assume I could just do all of this in a normal double-darkslide 4x5 holder.
    - Jeff (& sometimes Eva, too) - http://www.jeffbannow.com

  9. #9

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    Ideally I'd just put the sheet flat on a piece of black cardboard on the enlarger baseboard (to eliminate any chance of flare from the film holder along the edges of the film).

    What kind of tank/system for inversion?

  10. #10
    Jeff Bannow's Avatar
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    Quote Originally Posted by Michael R 1974 View Post
    What kind of tank/system for inversion?
    Mod54 in a Patterson tank.
    - Jeff (& sometimes Eva, too) - http://www.jeffbannow.com

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