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Thread: progess with paper negatives

  1. #21
    Actually, I like the position of the camera - after all, the plane is one the ground.

    Cheers -

    george

  2. #22

    P3

    Nice photo of the Orion!
    We used to see much more of them in past years.
    I work across the fence from there...

  3. #23
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    Hi
    I wish to use ISO 3 paper negative for pinhole camera.Please can you recomendation any pinhole calculator to determinate EV for this paper.I wish to use light meter on f/16 and determinate on f/160(my pinhole camera).On www.pinhole.cz I can finde onlly calculator for ISO film 100
    Thanks for answer

  4. #24
    Quote Originally Posted by fago View Post
    Hi
    I wish to use ISO 3 paper negative for pinhole camera.Please can you recomendation any pinhole calculator to determinate EV for this paper.I wish to use light meter on f/16 and determinate on f/160(my pinhole camera).On www.pinhole.cz I can finde onlly calculator for ISO film 100
    Thanks for answer
    G'day fago
    I've never understood, think about or use EVs.

    What I'd do is;
    - accept that f160 is close enough to f180
    - f180 is f22 plus 6 stops
    - set meter, in my case an old EOS film camera, to its lowest ISO of 6
    - take a meter reading of a mid tone at f22
    - double the shutter speed to get to ISO 3
    - double the shutter speed 6 times to get to f180, Ive actually made up a little table
    - make exposure

    Now;
    what about the lighting conditions? Variable contrast paper is difficult to expose correctly depending on, I suspect, the amount of UV in the light.
    Will you need a yellow filter if using variable contrast paper? A yellow filter will nicely reduce contrast in variable contrast paper but will grossly under expose graded paper.
    Will you use RC or FB paper? I prefer the softness and grain when contact printing FB paper.
    "The mission of photography is to explain man to man and each man to himself", Edward Steichen, in Arthur Rothstein 1986, 19.

  5. #25
    Quote Originally Posted by fago View Post
    Hi
    I wish to use ISO 3 paper negative for pinhole camera.Please can you recomendation any pinhole calculator to determinate EV for this paper.I wish to use light meter on f/16 and determinate on f/160(my pinhole camera).On www.pinhole.cz I can finde onlly calculator for ISO film 100
    Thanks for answer
    Ray's method works fine. Mine's a bit different. I use a handheld meter where I take a reading at some f-stop different from the camera's, then multiply the recommended exposure time by a correction factor to arrive at the correct exposure time. For your camera, and metering at f/16, the formula for the correction factor is: (160/16)^2 = 100. So, multiply the meter's recommended exposure time at f/16 by 100 (using seconds as your units) to get your correct exposure time.

    When you meter the scene (with a light meter), be sure to set the paper's ISO on the meter to your value of 3.

    Your pinhole camera's focal ratio, and your desire to meter at f/16, gives you an easy-to-remember correction factor of 100. Myself, I use the largest f-stop on my meter, f/128, and end up with hard-to-remember correction factors that I affix to my cameras with a label maker. And I carry a little pocket calculator around with my camera kit. For instance, my Zorki-4 rangefinder converted to pinhole has a correction factor of 1.49.

    Good luck and be sure to post some results here.

    ~Joe
    "There was just that moment and now there's this moment and in between there is nothing. Photography, in a way, is the negation of chronology."-Geoff Dyer, "The Ongoing Moment"
    My Writing Blog: Joe Van Cleave's Blog
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    Visit my F295 Gallery

  6. #26
    500+ Posts Ned.Lewis's Avatar
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    Ray's method is fine, Joe's method is fine, mine is a little different! All will get you to the same answer.

    What I do:

    For each camera, I find by trial and error what is the best exposure for mid-day "sunny 16". I don't calculate this value based on the "ISO" of the paper or the calculated F/ of the camera. I make a series of test photos to home in on the best negative. Then for each camera I only need to remember one number, like: "20 seconds" or "45 seconds" or "1 minute".

    When I meter, with a different camera or a light meter or by "guesstimate", I am finding how many stops different from "sunny 16", which is how many times I need to double the exposure for that camera.

    You can get an approximate "base seconds" for a new camera with just a few tests, then over time if you find your negatives are slightly under or over-exposed, you can vary it slightly to get it perfect. I like doing it this way because it uses the actual physical camera with all it's characteristics of the pinhole and shape etc. After you have made a few cameras, you won't even need to test... you can usually guess the base exposure and be close enough to start using the camera successfully, making further adjustments to the "base time" as you gain experience with the camera.

    When I use a paper negative in a camera with a lens, I do something more similar to what Ray and Joe are suggesting, although even then I convert quickly to "sunny 16" thinking. My paper is "ISO 12" straight or "ISO 3" with my yellow filter, again for midday.

    Have fun!
    Last edited by Ned.Lewis; 06-11-2014 at 01:30 PM.
    Some photos: Ipernity
    ( pinholes and solargraphs mixed in among the rest)

  7. #27
    That's pretty close to how I do it. After testing I commit the information to a piece of paper which is laminated and kept with the camera, as there is no way I'll remember what works best with which camera. The film (oftentimes x-ray film, in my case) is a big part of it, so that should also be recorded.

    Cheers -

    george

  8. #28
    Senior Member dwerg85's Avatar
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    If you have an IOS device (iPhone, iPad, iPod) you can use pinhole assist. You just put in ISO and f/ stop and you'll get a exposure time. I've been trying out using the luxi addon for incident metering which seems to work pretty well too.

  9. #29
    wow lots of cool info, and interesting approaches. I basically did the sunny 16 rule, I metered the scene
    determined what I would do for f/16, then made an in-camera test strip by moving the darkslide every
    30 seconds for 8 minutes, another test narrowed it down. I taped on my camera "9.5 stops passed f/16".
    It has worked fairly well. These images are the first overexposed I've had with tpaper negatives and yellow filter
    I actually waited through 10 stops past f/16...

    Upper Dana fork of Tuolumne River, 24 minutes

    img698.jpg

    Above Tenaya Lake, 32 minutes [took a nap]

    img697.jpg
    The memory of things gone is important to a jazz musician.
    Things like old folks singing in the moonlight in the back yard
    on a hot night or something said long ago.
    - Louis Armstrong

    https://www.flickr.com/photos/stormiticus/tags/pinhole/

  10. #30
    500+ Posts Ned.Lewis's Avatar
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    Those are nice! A lot more UV up there... although I'd think the yellow filter would stop most of it.
    Some photos: Ipernity
    ( pinholes and solargraphs mixed in among the rest)

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