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  1. #1

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    Mar 2008
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    P-Sharan STD-35 and exposure

    Hi there,
    I built myself a P-Sharan STD-35 pinhole camera for a bit of fun http://www.sharan-camera.com/ but I can't quite figure out the suggested exposure times. The pinhole is stated as being 0.16mm to give F/130 for 20mm focal length which seems about right, but the suggested exposure time for ISO 100 film is 2-3 seconds for sunny conditions and 3-4 seconds for cloudy. Using the sunny F/16 rule, I would guess that F/130 should be about a half a second, so the recommended time should be about 2 stops over-exposed. The funny thing is, when I stick to the recommended times, they negatives are well exposed, but if I meter the scene and use F/130 shutter speeds (around 1/2 a second for bright sun) the negatives are underexposed. Any idea what might be going on?
    Ta!

  2. #2

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    Sep 2011
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    Olympia, wa.
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    I have found most exposures on pinhole to be "cut and try". After standardizing on the film (or paper), the developer, etc I make a series of test exposures and from that derive correct exposures for future use.

    Yeah, I don't understand why it doesn't conform to caculations either. Oh well.

  3. #3
    MattKing's Avatar
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    Apr 2005
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    reciprocity failure?

    inaccurate size given for pinhole?
    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

  4. #4
    Fixcinater's Avatar
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    Dec 2008
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    I have the same kit, and ran an expired roll of BW400CN through it for a first test run. I guessed most of the exposures, and most of the failures were underexposure, with only one completely blown out frame on the roll.

    I tend towards overexposing negative film anyway, so just a bit more time than my normal guesstimate and it seems to be happy.



 

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