----- Original Message -----
From: <Photoed77@aol.com>
> I never heard of anyone using a slide projector to find the optimal
pinhole
> aperture. Somebody else out there might have heard about it.
Slide projectors, enlargers and even scanners (
http://members.home.com/penate/diameter.htm ) have been used, NOT to find
the optimal pinhole aperture, per se, but to simply find the diameter of the
hole.
> There are many formulas that various pinhole photographers have used.
Many
> have their own personal formula.
All the formulas are in essence the same, all are of the form:
Diameter = SQRT( Constant * light wavelength * focal length )
As for the Light wavelength, everybody uses "generally speaking" around 550
nanometers. The real and only difference would then be the value of the
Constant.
> Some pinhole photographers do not want the most optimal aperture. They
> prefer a softer or blurred image.
That's right, but to be 100% sure the pinhole you are using is not "optimum"
(before any exposure is made) you'd have to measure the pinhole.
Guillermo
Received on Sun Apr 8 09:33:58 2001
This archive was generated by hypermail 2.1.8 : Mon 13 Dec 2004 - 23:33:20 PST