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  1. #1

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    2 Unknowns--Exposure & Develpment

    OK, got my lensboard made and lens mounted on my 8x10. On Tuesday my Fuji Green X-Ray film comes and I'm off to the races. I've followed a thread on LF Forum, but it is a long thread of mostly back-patting on each other's shots. So I've thought up my own procedure to get a ballpark exp and development. So lets start with straight D-76 in a tray
    I'm thinking find a development starting time first, then move on to finding a film speed. Starting with what I might know as a standard, is that I BELIEVE film speed will be 80-100 range. So, I figure to shoot a fully exposed negative of a big sheet of white paper, with the camera, placing it on Zone 9-10, with a metered film speed of 40. This should give a fully exposed piece of film, but not absurdly exposed, like laying the piece of film on the table with sunlight coming in the window.
    Then, cut that film up, and make progressive developments of the pieces. Not having a densitometer, I figure to use my Luna-Pro pointed at some fairly bright lighting (so as not to overwhelm the meter cell). Then hold each piece of film up to the meter cell until I get to the one that shows no change in the reading. Somewhere between this piece and the piece before it SHOULD be a ballpark development time.
    From that point, begin cutting up more film to 4x5's and use a step procedure till I see detail in Zone 1, or perhaps just shoot a Kodak step wedge till I see a reasonable progression. This should be a base exposure for trial.
    So now I should have a ballpark film speed and development time that I can tweek from there. Opinions? Thank you.

  2. #2
    MattKing's Avatar
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    Don't use a piece of paper.

    Use something like a white towel - something with texture.

    I'll let others comment on the rest of your procedure.
    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

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    ic-racer's Avatar
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    Shoot any uniform surface without texture illuminated by light you normally use (ie tungsten vs daylight). Focus lens at infinity. Shoot zone I. Place processed negative over light meter, the frame that drops exposure by 1/3 stop = 0.1 log d = good exposure index.

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    Bill Burk's Avatar
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    Quote Originally Posted by Tom1956 View Post
    until I get to the one that shows no change in the reading. Somewhere between this piece and the piece before it SHOULD be a ballpark development time.
    Do you mean clear & practically clear (then you would be placing the tone on Zone I or II) - or Black and So Black the meter can't tell any more (over 2.0 density - then your plan is fairly reasonable)

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    Bill Burk thank you. I do not exactly understand your post. So yes, I meant black and so black the meter can't tell. Is this right? Or are you saying go the other way--no density and first hint?

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    Bill Burk's Avatar
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    Quote Originally Posted by Tom1956 View Post
    Bill Burk thank you. I do not exactly understand your post. So yes, I meant black and so black the meter can't tell. Is this right? Or are you saying go the other way--no density and first hint?
    Ah, then your plan will probably work fine.

    Traditionally tests for speed are done first, the tests for 0.1 density. Because this doesn't change much over a wide range of development times. So I recommend you look for this first.

    When you do the development times tests, keep in mind, your meter probably will be able to accurately measure a dark Zone VIII / Zone IX test negative that is developed the right time.

    Compare the meter reading with nothing... to the meter reading with your dark test negative. The dark negative that the meter tells you is 4 stops darker than nothing will have 4 stops x .3 density per stop = 1.2 density... Which is a reasonable Zone IX target.

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    Thanks. I really wanted to standardize my process for Pyrocat HD, which I've never used before. But they want $19.60 just to ship the 12 dollar product. That's 30 some-odd dollars just to get some in the house, and I have to watch every penny. I've got several packages of D-76 lying around, so D-76 it is. Frankly I have an idea I'm going to be fighting an excess contrast situation, but we'll see.

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    Quote Originally Posted by ic-racer View Post
    Shoot any uniform surface without texture illuminated by light you normally use (ie tungsten vs daylight). Focus lens at infinity. Shoot zone I. Place processed negative over light meter, the frame that drops exposure by 1/3 stop = 0.1 log d = good exposure index.
    Thank you ic-racer. Will do it that way. I still like the idea of ball-parking development time first. Then do this. And if a repeat of this process is performed, logically one would have it nailed.

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    Bill Burk's Avatar
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    Quote Originally Posted by Tom1956 View Post
    Thank you ic-racer. Will do it that way. I still like the idea of ball-parking development time first. Then do this. And if a repeat of this process is performed, logically one would have it nailed.
    The "problem" with that approach is, to know what exposure Zone IX would be, you kind of have to have an idea what speed the film is...

    And the 0.1 density test results do not change dramatically with development time.

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    Quote Originally Posted by Bill Burk View Post
    The "problem" with that approach is, to know what exposure Zone IX would be, you kind of have to have an idea what speed the film is...

    And the 0.1 density test results do not change dramatically with development time.
    Thanks, Bill. But this is one of those things I need to start somewhere on guessing a development time. 2 mins? 4?, 10? I need to knock that problem down to at least a vague idea.

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