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Thread: roll back pinhole camera

  1. #11
    Lord Rayleigh approached pinhole photography more as a scientist than as a photographer. Photographers often arrive at slightly different formulae based on experience. For the best resolution of a test chart in the center of the photograph, I use PinholeDesigner with a user constant of 1.4 for panchromatic film. Yes, the color of the light source and the color response of the film does slightly affect the optimum pinhole diameter. I'd use a 0.33mm pinhole in Blindpig's camera. Also, the pinhole diameter can be slightly reduced for close-up photography. Since the ultimate goal of pinhole photography to most photographers is the photograph, not the validation of scientific theories, experimentation is in order. We each have our individual tastes.

  2. #12
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    It's difficult to say from the images of the camera but, I wonder if the slight loss of sharpness is could be due to movement?

    Although I can see the camera is fixed to a base on the tripod, is the cardboard end with the pinhole? As you say it was slightly windy I wonder if the pinhole end could be 'flexing' VERY slightly in the wind, even if the film back part is rock solid. It's only going to need a very tiny amount of movement to make the images appear unsharp (something like 0.2mm flex would make a lot of difference).

  3. #13
    I'm sorry to have to tell on myself but after fooling around with moving the pinhole forward and back 1/4 and 1/2 inches and seeing improvement in the forward movement pictures I quit for the day.I woke up in the middle of the night and thought,why not put the pinhole on my Graphic and focus on the ground glass then measure the pinhole to film distance? My only excuse for not immediately coming up with this I'm going to blame on age!
    The files in my head are evidently large enough to slow down access,LOL! So later I'll test this theory out and make some pictures(hopefully sharper).Again my mantra will out "Even a blind pig finds an acorn once in a while".
    Don

  4. #14
    500+ Posts Ned.Lewis's Avatar
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    Hi Don,

    That sounds like a clever idea but I'm not so sure it will work. I tried something similar when I built my little pinhole polaroid conversion. I put paper negatives in it and swapped out the pinholes until I got one I was happy with. There was not much similarity between the "look" and sharpness of the results on paper negatives and on the color instant film. I suspect looking at a color image on ground glass and then using paper negatives will have a similar problem.

    At least with paper negatives, it's quick and cheap to make test shots!!

    Ned
    Some photos: Ipernity
    ( pinholes and solargraphs mixed in among the rest)

  5. #15
    Here's the first test after adjusting focal length,think it's much better.Camera is in garage so no wind problem and I reduced the overall size of the shim/pinhole material in case of some movement there,also attached an aluminum plate to the camera mount for strength.All in all am happy with result(but may play around a little more to see if it will improve)never satisfied I guess...

  6. #16
    500+ Posts Ned.Lewis's Avatar
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    Looks good to me!
    Some photos: Ipernity
    ( pinholes and solargraphs mixed in among the rest)

  7. #17
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    So much sharper - (for what ever reason)

  8. #18
    Thanks guys.I'd like it a little sharper but considering the paper negative is an ideal format 2 1/4 enlarged about 500% give or take,maybe I should be satisfied(for now).
    Don

  9. #19
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    Using a pinhole camera, you cannot afford to spent much time advancing the film since you have to dedicate it to exposure... hence the rapid advance is an advantage :-)
    The world is not black and white. It often looks good in grayscale, though.
    http://www.flickr.com/photos/msgallery/sets/

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