From: Pam Niedermayer (pam_pine@cape.com)
Date: 05/08/00-03:18:39 PM Z
Is it true you can focus a zone plate image? If so, I think
I'll do something with the view camera, also just play
around a bit with some Polaroids. I've been meaning to do
this with a regular pinhole for a while, so maybe a combo experiment.
Pam
Judy Seigel wrote:
>
> On Mon, 8 May 2000 erobkin@uwc.edu wrote:
>
> > If you shine a beam of light through a pinhole the image you get has
> > alternating rings of dark and light because of interference phenomena. A
> > zone plate is an idealized version of those images with the dark rings made
> > completely opaque and the light rings as clear as possible. Because of
> > interference actions light shining through the zone plate behaves like it is
> > going through a pinhole but the amount of light is increased.
> >
> > Much detail and technical tradeoffs between pinholes and zone plates left
> > out.
>
> What I haven't seen mentioned is that the zone plate image is usually
> quite distorted, an artistic softening and warping that can be very
> beautiful, but not necessarily what one wants, or "working" with every
> image.
>
> Judy
>
> .................................................................
> | Judy Seigel, Editor >
> | World Journal of Post-Factory Photography > "HOW-TO and WHY"
> | info@post-factory.org >
> | <http://rmp.opusis.com/postfactory/postfactory.html>
> .................................................................
-- Pamela G. Niedermayer Pinehill Softworks Inc. 1221 S. Congress Ave., #1225 Austin, TX 78704 512-416-1141 512-416-1440 fax http://www.pinehill.com
This archive was generated by hypermail 2b29 : 06/13/00-03:10:18 PM Z CST