Large format pinhole camera

Discussion in 'Large Format' started by j_nanian, Dec 2, 2001.

  1. i have been shooting large format with lenses for years, and was
    interested in making a large format lens-less (pinhole) camera.
    right now i regularly shoot 4x5 and 5x7 and i wanted to go maybe
    to 7x17 or 8x20 and shoot paper negatives. i have micro drilled
    shims, and plans for making the "box" ...
    has anyone every made a really BIG pinhole camera?
    will i have any problems with image circle / coverage ?

    <p>

    thanks in advance!
    john
     
  2. John:

    <p>

    I built an 11x14 Pinhole several years ago as a bridge to larger
    format cameras. My 11x14 pinhole has a focal length of about 5" and
    uses a .016" pinhole. This arrangment covers 11x14 although you do get
    the light falloff characteristic of pinhole shots.

    <p>

    If I remember correctly, the relationship between focal length and
    image circle is approxiately 1:3.5. Thus, a 1" focal length pinhole
    camera will produce an image circle of 3.5". For the larger film
    formats you will need a minimum FL starting at about 5-6 inches.

    <p>

    ...................................
     
  3. Dave:

    <p>

    Out of fascination, can you remember what the length of exposure was
    under "sunny 16" conditions?
     
  4. thanks dave -
    if / when i build it i'll post my results :)
    - john
     
  5. Go to:http://home.online.no/~gjon/pinhole.htm. Jon has alot of useful
    info. If you also plug in "homemade cameras" into your browser, you
    will get so many sites!!!!
     
  6. I built an 8x10 pinhole a while ago. It has a focal length of 8.25"
    and an f/346 .
    I purchased a laser-drilled pinhole from Lenox Laser - they drill
    these in 1/5000th stainless and mount them on a 3/4" disk.

    <p>

    The camera itself is a plywood box with an 8x10 spring/back from an
    old Kodak. I have only used film so far, but you could use paper in
    the holder as well.
    I initially had recessed the disk (with pinhole) and made a 1.4" hole
    in the wood, but the edges of the wood showed on the negs.(the disk
    with pinhole is mounted on the inside surface of the box), so I had to
    enlarge the hole to about 3/8" -

    <p>

    I like it alot!
     
  7. This does not answer your question, but I thought I would chime in.
    I am a LF in focus kinda guy. But, a while back I purchased a 4x5
    and 8x10 Leonardo(used) and I must say they can be a kick in the
    butt. I carry the 4x5 with me most of the time and I find playing
    with the pin holes to be a great break. There is no dissatisfaction
    in a soft focused finished print because it's "supposed to be that
    way" so a lot less pressure.. And I have a lot of fun trying to play
    around with motion. It's also a great way to introduce a kid to
    photography at a very basic level. And you really can have cars and
    people go by and not get in the photo. I purchased my 4x5 at almost
    new price and the 8x10 for $15.00 with a holder. Check out Eric
    Renners(sp?) Book
    and site.

    <p>

    Good Luck,

    <p>

    Mac
     
  8. There's a great pinhole discussion forum at www.pinhole.com
     
  9. A spin-off question:

    Considering the rule of thumb for pinhole circle of coverage being about 3.5 x f.l., does using a longer f.l. than 'normal' for a format reduce the falloff?

    Numerical example - 4x5 bellows camera, pull the lens board, put in a pinhole board with right size hole for 300 mm, and extend bellows to 300 (or whatever), and still use a 4x5 filmholder, does the edge falloff end up being way out beyond the diagonal of the 4x5 film, and thus have a 'telephoto' perspective with more even illumination than one would have with 4x5 film, 150-160 mm bellows position?

    Thank you.

    Murray
     
  10. Please note that in October 2015 my webpages on building large format cameras move to: jongrepstad.com
    Jon Grepstad
     

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