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Thread: LIght Pipe Array Camera

  1. #21
    Quote Originally Posted by Ned.Lewis View Post
    I had no idea what to expect. I wonder if the image is reversed within each "pixel", or if there really is an image projected by each one. Could be an aggregate tone for the light in each tube I suppose, in which case smaller tubes = more detail. Thanks for sharing this!
    I think you've hit on the fundamental operating principle, which is each pipe averages the light level from its individual field of view. Thus, smaller tubes equal more detail. Going forward, I'm going to be working on finding affordable smaller tubes, and building a larger format version. Probably employ a true barn-door type of shutter for exposure control. I see one use as a portrait camera, 8x10 format. Lotsa tubes!

    ~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
    My Pinhole Blog: Obscure Camera
    Visit my F295 Gallery

  2. #22
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    Hi Joe, how about something like this:

    http://www.ebay.com/itm/2pc-3-0mm-OD...item2a2e001231

    2mm inside diameter. Square outside so you could stack them easily and you won't get light leaking between the pipes?

    Simon

  3. #23
    500+ Posts Ned.Lewis's Avatar
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    Probably too expensive, but imagine an 8x10" bundle of close packed fiber optic cable...
    Some photos: Ipernity
    ( pinholes and solargraphs mixed in among the rest)

  4. #24
    It might be worth contacting Corning Glass and asking them if they have anything that they can't use or sell, you might be surprised. I would definitely show them what you already accomplished so they have an idea of what you are trying to do.

    I think you will still need some kind of aperture in the front to focus the light, else you need contact to maintain an image. The Mamiya 7 camera had an instant film back that placed densely packed light pipes at the image plane, and conducted this to essentially contact the instant film which was about half an inch behind the normal film plane. Seemed to work pretty good considering the professional level those cameras were used at.

  5. #25
    @Ned: I've thought of that idea already, the main problem being that, even with precisely cut fibers, they won't form an image without having an optical image projected onto the end of the bundle. Light pipes (i.e. tubes) don't have that problem, as the ends are open to directly conduct whatever light is available down the tube toward the film plane.

    @Greg: Good idea. I've thought of using thin glass tubes, like those used in the medical industry, if the price were right. Not entirely certain about optical isolation between tubes when they're transparent and in contact with their neighbors. I'm assuming the light coming down the tubes reflects off the side walls at a glancing angle less than the critical angle for reflection, so very little of the light should cross-conduct into neighboring tubes.

    So far in my research, carbon fiber tubes for the model aircraft hobbiest and stainless hypodermic tubing both seem readily available in ~1mm I.D. sizes, though I would want to get bulk rate discounts if I could manage it.

    Regarding the exposure calculations from the last round of tests (posted above), much of the discrepancy between my assumptions about aperture values and the results using paper negatives has to do with reflected light bouncing down the tubes and adding to the exposure. F-stops are normally calculated given the assumption that light is diverging from the source at the inverse-square rate. A tiny cone of light does strike the film from the center of each light pipe via the inverse-square law, but much more light, from angles other than strictly parallel with the axis of the tube, bounce along the inside walls, adding to the exposure.

    There's also the issue of the reflectivity of the material of the light pipe. I seem to have noticed variances in exposure results between scenes exposed in my covered patio lit by indirect north light and scenes indoors lit by indirect daylight only. In the case of the indoor exposures the results were less exposure that the meter readings would otherwise suggest. I'm guessing it has to do with the indirect nature of the diffuse light, being absorbed by the inside surface of the light pipe tubes rather than being reflected down the tubes as is the case with more direct lighting. I've used these same lighting conditions with paper negatives and glass-lensed cameras with no issues before.

    So more investigation is needed.

    ~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
    My Pinhole Blog: Obscure Camera
    Visit my F295 Gallery

  6. #26
    If you look around, I think you can find smaller CF tubing, but for anything larger than a 8mm sized frame it is going to get expensive fast. It will also get you down into pinhole sized internal diameters. Think I have some .5mm outside diameter tubing which would put the inside at around .3mm or .2mm.

  7. #27
    500+ Posts Ned.Lewis's Avatar
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    Thanks Joe,

    That explains a few experiments I've read about using fiber optics as a magnifier or to translate an image. They all had lenses on one end or the other or both.

    There is something primitive and fundamental and fascinating about this idea of yours. The image formation is from the length of the tube, limiting the field of view in each one. Have fun with it!
    Some photos: Ipernity
    ( pinholes and solargraphs mixed in among the rest)

  8. #28


    Yes. 25 packs of 1/8"OD black plastic straws, 170 to a pack. That's 4270 straws for the next version of the Light Pipe Array, which I hope to be an 8"x10" format. Though I could have purchased these via Amazon, instead I visited four of my local Target stores and bought out their entire stock.

    I'm certain there's some corporate bean counter at Target headquarters scratching his/her head over this sudden surge of sales. Perhaps they'll contact the Feds, on general suspicion. Perhaps there's already a huge version of this camera floating high overhead, or buried under some mountain in southern Nevada. The beauty of a conspiracy theory is that lack of evidence is sufficient proof.

    Regardless, I'm pressing forth on the project, slowly.

    ~Joe

    PS: Photo via Hipstamatic app, hence all the faux filmy-like colors.
    "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

  9. #29
    They are probably trying to figure out how these are used in drug creation.

  10. #30
    I'll probably need a few more packs of straws. 8"x10" size with 1/'8" OD straws implies (8x8)+(8x10) = 64 x 80 = 5120 straws total needed. My 25 packs of 4270 straws implies (5120-4270)/170 = 5 more packs needed. Time to hit up another few Target stores.

    ~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
    My Pinhole Blog: Obscure Camera
    Visit my F295 Gallery

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