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Thread: My first pinholes since college

  1. #1
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    My first pinholes since college

    Hey everyone, I'm new here but I love the forum. I'm working on a longterm project hopefully involving weeks-long exposures, so I've built my first pinhole in years and want to share what I've gotten so far.

    It's a pretty standard foamcore 4x5 box with a film holder back. had absolutely no lights leaks on the first try! I just used a beading needle from my roommate to poke a hole thru some aluminum foil for the pinhole and it works surprisingly well. Certainly better than any attempt I made when I was a student.

    I haven't found a really reliable way to guess exposures yet. I'm metering at f/8 with incident meter, and converting with the mr pinhole exposure chart. it's all over the map, sometimes it's way over exposed, and sometimes there's barely any latent image. *shrug* I'm just gonna keep at it until I find a formula that works.

    Here's a couple of the best test I've done so far.

    07-17-15---Drive-from-LGA-[f235-@-45-min].jpg
    approx. f/235 @ 45 min on Harman direct positive.

    07-18-15---33-Crooke-ave-[f235-@-15-min].jpg
    approx. f/235 @ 15 min on Harman direct positive.

  2. #2
    500+ Posts Ned.Lewis's Avatar
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    Welcome! Weeks long exposures sounds like a great project to me. Looks like you are off to a great start.

    Different folks here at f295 all have their favorite ways to calculate exposure. I think if you search through the threads you might find conversations about the different ways people do it. Personally, I find a single "sunny 16" time for each camera by experimenting, and then I base all the times for that camera off that value. So for example, if the SS time is 20 seconds, and I meter or guess that I need 1 stop more exposure then I double the time to 40 seconds, and so on. If I'm using a light meter or a film camera or a digital camera as my meter, I just need to see how many stops away from 1/iso it reads for f/16. If I don't have a meter, then the usual "sunny 16 rules" work well, but add an extra 1/2 stop for late afternoon or early morning sun angle ( at low angles the atmosphere blocks relatively more blue light ) or a full stop if the sun is really low. I use paper negatives almost exclusively, and there is almost no reciprocity failure, so this works even for exposures of an hour or more. I mostly use my cameras outdoor; indoors is harder with different light sources etc...

    Have fun!
    Some photos: Ipernity
    ( pinholes and solargraphs mixed in among the rest)

  3. #3
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    i was curious about reciprocity failure for paper. when calculating my exposures I just ignored it and hoped it'd be ok.

  4. #4
    500+ Posts Ned.Lewis's Avatar
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    Someone else can probably chime in about reciprocity failure for your direct positive paper, but I'd be surprised if there is a lot. Cheers!
    Some photos: Ipernity
    ( pinholes and solargraphs mixed in among the rest)

  5. #5
    Those are some cracking good images, well done. And welcome to F295.

    There's no right way to meter for pinhole, and everyone seems to have their own preferred method. Mine is to use a Gossen Luna Pro F. For grade 2 RC paper I use ISO 12, and reference the highest f-stop on the meter, that being f/128. I make note of the exposure time, in seconds, for f/128, then convert the time for my camera's aperture, thusly:

    Camera Exposure time = (Camera's focal ratio/128)^2 times (meter's time for f/128).

    Since, for any particular camera and pinhole, the term "(Camera's focal ratio/128)^2" is a constant, I calculate this number ahead of time and affix it to the camera with a label maker. So out in the field, all I have to do is multiply the meter's recommended time for f/128 by this factor and that's my working exposure time.

    For this paper I don't apply any reciprocity correction, and it has proven accurate out to more than 5 minutes.

    For Harman Direct Positive Paper, I do the same, except I vary the ISO depending on the contrast of light. For bright daylight I use ISO 6, while for shaded daylight I use ISO 1.6 - 3, depending on how contrasty it is.

    Artificial lighting is trickier, since my meter is panchromatic but the paper is mostly blue/UV sensitive. The meter will tend to under expose, since it's seeing light that the paper isn't sensitive to, so I typically add a stop of exposure, depending on whether the light is incandescent or compact flourescent, and whether there's a mix of window daylight also.

    For daylight exposures, I may also add a stop of exposure if the subject is brown or reddish in color, since paper lacks sensitivity to these colors.

    I also meter the principal subject in the scene, and try not to meter the sky itself, since doing so results in the landscape being grossly under-exposed. I just let the sky blow out to white, as was common with 19th century landscape images.

    I did do some experiments a few years back with photographing white clouds against the blue sky, in which case I did meter the sky and expose accordingly. Surprisingly, I was able to get good separation between the sky and clouds.

    ~Joe
    Last edited by JoeVanCleave; 07-20-2015 at 12:59 AM.
    "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
    My Pinhole Blog: Obscure Camera
    Visit my F295 Gallery

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    thanks joe, good tips!

    I shoot 4x5 lens-based stuff too, so I tend to shoot for the shadows. I'm beginning to think that maybe I should not even worry about trying to get the sky exposed nicely with a paper negative (or positive in this case). I've got some orthochromatic film that I'm going to try out too. Any tips for that? I imagine it should be the same as paper (though I'm a little concerned about reflections off the film inside the camera).

    the longterm project I have in mind is of a set build inside a theater that i have coming up. should be about two weeks sometimes with low light, sometimes bright theatrical lighting. I hoping that with slow enough paper/film and a bunch of ND filters I can get something cool. but I'm taking baby steps to make sure it'll work before I blow the opportunity on a dud camera. obviously, an option is to build a dozen cameras to have redundancy (which i'll probably do anyway). my inspiration is from michael wesely's shots of the MOMA construction a while back, though he seems to be a little tight lipped on how he did it.

  7. #7
    those are nice images, the second one, with the fence and barbed wire intrigues me, nice urban work.

    When I made a new camera, I pulled dark slide a bit at a time, exposing the paper in sections of 5 minutes.
    took awhile, but with one 30 min exposure on a sunny day, I got a good starting time for my camera.
    Keep it up, looking forward to more.
    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/

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    Quote Originally Posted by dasBlute View Post
    those are nice images, the second one, with the fence and barbed wire intrigues me, nice urban work.

    When I made a new camera, I pulled dark slide a bit at a time, exposing the paper in sections of 5 minutes.
    took awhile, but with one 30 min exposure on a sunny day, I got a good starting time for my camera.
    Keep it up, looking forward to more.
    of course, why didn't i think of that. good ole test strip technique

  9. #9
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    got a pretty successful one out in the wild:

    07-20-15---Union-Square-[f235-@-7min-30-sec].jpg
    Union Square, NYC. shot through a glass window for what seems to be a good starting point for a sunny 16 standard: 7.5 mins.

    Figured it was time to try the next experiment, orthofilm. I should have done a test-strip style exposure, but I had dinner to help cook, so I just left it going for three hours (which is what I metered for without pushing or pulling).
    07-21-15---living-room-[orthofilm][f235-@-3-hours].jpg
    It's so dirty and the highlights are so blocked up I didn't think it was worth it to spot clean it in PS. Not thrilled with the results, but I probably did agitate it too much in development.

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