Re: pinhole camera

j.r. pierce [see .sig] (antispam@here.not)
Sun, 06 Apr 1997 20:30:28 GMT (Laurie) wrote:

>Has anyone ever made their own pinhole camera? If so, what were your
>results like? I have some directions on how to make on but I am
>relucant to do so as of yet. I am also having a hard time finding the
>126 film it asks for. Any tips on where to buy it? Thanks in advance!

I did once a long time ago. We used 4x5" Tri-X sheet film and pushed
it to about asa1000 in the darkroom. 126 was the OLD instamatic,
yuck. You -probably- could modify the plans for 110 pocket

For any given 'focal length' (really pinhole-to-film distance) there
is an optimal pinhole size. Any bigger, and the image is blurrier
because of the size of the hole. Any smaller and the image is
blurrier because of diffraction. I forget the formula. I believe its
around f/64 or f/90 (diameter / distance). The distance, of course,
determines the magnification. Whatever this f/ ratio is, you compute
your exposure based on that. With asa100 film, a typical exposure in
bright daylight might be 1/2 second @ f/64 or 1 second @ f/90.

Mostly I've used pinholes to view solar eclipses and even major
sunspot activity, projecting the sun onto a screen maybe 3' from the
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