Re: zone plate distortions, was RE: Zero pinhole camera

Date view Thread view Subject view Author view

From: Pam Niedermayer (pam_pine@cape.com)
Date: 05/09/00-12:46:29 AM Z


Would this hold if the film/paper is held in more of a
sphere attitude rather than flat?

Pam

Sam Wang wrote:
>
> At 9:22 PM -0400 5/8/00, Judy Seigel wrote:
> >
> >Actually I was thinking of the zone plate pinhole prints by a onetime
> >student of Sam Wang's that I saw in The Pinhole Journal. So either I
> >generalized from the particular mistakenly, or what to me looked "soft
> >and distorted" wasn't -- or anyway not to someone else !
> >
> >Judy
> >
>
> Sorry, but I was buried under end of semester grading and have not
> been able to dive in till now.
>
> Yes, zone plates do distort. For normal focal lengths, no. But once
> you use it as wide angle, you will find quite pronounced pincushion
> distortion, especially if you use a red filter to sharpen up the
> central area of the image.
>
> Moral: don't photograph people's faces near the edges of the frame if
> you value their friendships.
>
> BTW, a red filter also shortens the focal length a tad.
>
> Sam Wang

-- 
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


Date view Thread view Subject view Author view

This archive was generated by hypermail 2b29 : 06/13/00-03:10:18 PM Z CST