Sharper pinhole image,Part Two

Discussion in 'Pinhole Photography' started by kevin klein, Aug 1, 2008.

  1. kevin klein

    kevin klein Member

    Messages:
    160
    Joined:
    Mar 20, 2006
    Shooter:
    Large Format
    I finaly did some more "try it and see" tests and found out a couple of things.

    The pinhoe used in conjunction with the camera lens is best.

    The smaller the pinhole the less sharp the image becomes.

    My thaught was that a smaller pinhole gives a sharper image but not so. The camera being used is a 4x5 and the pinhole is .018 or .020 aprox, brass shim stock blackened with a solution stained glass workers use to patina the leadding.

    The film being used is Kodak T max 400, exposures are quite fast, 1/2 -1 sec in sun, 10 sec in shade. when I get someone to post the pictures you can see some examples. (I am computer illitteriate...)
     
  2. Dave Wooten

    Dave Wooten Subscriber

    Messages:
    2,720
    Joined:
    Nov 1, 2004
    Location:
    Vegas/myster
    Shooter:
    ULarge Format
    Kevin, the pin hole size and sharpness is also related to focal length. There are optimal pin sizes for a particular focal length.
     
  3. bobwysiwyg

    bobwysiwyg Subscriber

    Messages:
    1,620
    Joined:
    Mar 28, 2008
    Location:
    Ann Arbor, M
    Shooter:
    Multi Format
  4. Tom Hoskinson

    Tom Hoskinson Member

    Messages:
    3,879
    Joined:
    Mar 7, 2004
    Location:
    Southern Cal
    Shooter:
    Multi Format
    Some Pinhole Design Trade-offs

    And, in general, the smaller the pinhole, the greater the diffraction effect.

    Pinhole design involves several trade-offs. Focal Length; pinhole size; light frequency; diffraction; size of the minimum acceptable size circle of confusion; are the ones I can remember off the top of my head.