>----- Original Message -----
>From: ELENABEAN@aol.com
>So heres my idea, now dig.
>I want to do some long exposures, IM talking like 24 hour exposures. I
wanted
>to make several small crude box pinhole cameras and tape them up all over
the
>city, leave them overnight and go and collect them in the morning.
>unfortunately I dont know a thing about pinhole exposures and am about to
do
>some experimenting.
People have done similar stuff, exposures of 24 hours and more. You say you
are about to do some experimenting, well that's is exactly what you have to
do. When you get to exposures that long, experimenting (trial and error) is
about the only way.
>I have a few questions about it.
>How far does the actual pinhole have to be from the film.?
As far or as close as you want it. Pinhole lenses behave very similar to a
glass lens. That distance is nothing but the focal length of your pinhole
camera. So, the distance obeys to the angle of view you want and obviously
the format size of your photo material.
>How long can I expose for.?
It depends on the amount of light. Again, for long exposures, experiment.
>how big should the pinhole be?
The so called optimum size is given by the following formula:
Diameter in inches = 0.0073 * SQRT(Focal length in inches)
If you want less "sharp" results increase the diameter.
>If you got answers, I got an ear.
I recommend you to read Pinhole Photography: Rediscovering a Historic
Technique by Eric Renner.
>thanks, Elena
Guillermo
Received on Sat Dec 30 07:15:31 2000
This archive was generated by hypermail 2.1.8 : Mon 13 Dec 2004 - 23:15:57 PST