Re: Fresnel lens image, alternative

[Tom Ford <tomford@THESCIENCESOURCE.COM>]

At 06:09 PM 4/23/01 -0400, Kyle wrote:
> Couple of students were just in my office- they are trying to get an
> advertising business started and they want to use poster size images
> which show different images from different angles (as you move
> realative to the poster you see different images)...

Bill Beaty and others offered timely suggestions for turning this need into
a myriad of optics lessons. If the students just want a stunning poster
that is within the grasp of simple technology, they can:

Cut wood strips of equilaterally triangular cross section, long enough to
match the vertical dimension of the poster, and mount them touching one
another across a support for the width of the poster. The more sticks, the
better the project; but the more tedius.

Take two photos (or posters) and cut them into vertical strips of an
individual width that matches the side of the triangular sticks, without
mixing the pieces (keep them in sequence).

Glue the strips from one original, in sequence, on the same facing side of
the sticks and those from the other original on the other face.

When one walks past the finished display, the view of one original hands
off smoothly to the view of the other. The technology is simple, the
process obvious, so the viewer is rewarded not only with the two images but
the satisfaction that comes from understanding how it was done. Thus the
whole is greater than the sum of the parts.

Tom Ford