Re: Pinhole sharpness.
Tue, 15 Jul 1997 17:02:10 -0600

In article <5qep1q$>, (fisheye) wrote:
> "Geoffrey V. Brown" <> writes:
> > Well, I got my pinhole pictures back, and the exposures were almost dead
> > perfect.
> > Sharpness, on the other hand, left something to be desired. The
> > material that I made the pinhole in was about 1mm thick. I think that
> > this might have caused some reflections and so forth, but I'm not sure.
> > Can anyone offer suggestions for improving the sharpness of the image?
> > Does it have to do with the pinhole size, or something else?
> The material made the pinhole in is much too thick. Find some brass shim stock. This is
> available at many hardware stores. The stock is flexible, but not too thin, maybe as thick
> as 16 layers of aluminum foil (but don't use layred foil, though a single sheet may be OK,
> but not very strong. The hole should be small , and may be drilled with a small bit, or put
> a needle in a pencil eraser and use spin that between the palms of your hande to drill a
> hole in the stock. A clean hole is also very important. Sand doun any burrs and use a
> magnifying glass to inspect the edges around the hole. It should be round and clean.

PMFJI, I have done a couple of projects like this, and have found the
best stuff to be the .001 or .002 " brass shim stock, it is much harder
than the Aluminium -- we also used disposable Al pie type sheets, and
easier to get a clean hole. Since doing this project with my classes, we
have located a ton of web sites devoted to pinhole -- do a search on
Yahoo on Pinhole Photography, Kodak has sheets too.

This is probably close to the thickness of Al. foil.

I found the shim stock at a hardware store, and if you want, I can
provide a couple addresses of manufacturers of the stuff. Used to be
able to get it at any auto parts shop, but newer engines evidentally have
better gaskets, etc. Time marchs on?

You kinda want to use a needle, not a pin, and "drill" it through. Also
, Pinhole Resource in N. Mexico? Eric Renner-- check out his book at the
library, fantastic source -- or buy it from Eric.

Compuserve Photoforum deals with this now and again, and some of the
Sysops are experts.


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