Xref: utzoo comp.graphics:4189 rec.arts.tv:8277
Path: utzoo!attcan!uunet!datapg!sewilco
From: sewilco@datapg.MN.ORG (Scot E Wilcoxon)
Newsgroups: comp.graphics,rec.arts.tv
Subject: How to view Superbowl 3-D
Keywords: TV 3-D graphic
Message-ID: <3230@datapg.MN.ORG>
Date: 23 Jan 89 06:02:50 GMT
Reply-To: sewilco@DataPg.MN.ORG (Scot E Wilcoxon)
Distribution: na
Organization: Data Progress, Minneapolis, MN
Lines: 68

I don't care for the Diet version of Coke, so I don't have
the "official" 3-D glasses.  Nevertheless, I taped the
Superbowl halftime show in case it was worth later getting
the glasses.  I found the 3-D effect can be viewed from
the tape (SP speed) as well as live.

All I knew of the glasses was what was shown on TV, with
an almost clear left lens and a dark right lens.  I
suspected the right lens was either polarized or was
creating an interference pattern (perhaps both), as
the image was supposed to look good without glasses.

While watching the show live, I found the 3-D can be
seen by looking with the right eye through a narrow slit.
The left eye should be uncovered.  The slit was about as
far from the eye as a pair of glasses (I wear glasses,
and I simply had the slit on my right lens).

When looking only through the right eye, the slit should
be narrow enough to cause any TV image to have a series
of narrow horizontal bands.  The bands look to me like
an interference pattern, so they are an optical effect
of the small slit.  A single slit works if it happens
to cover most of the TV image.

With a little experimentation later with the taped
image, I found three objects which work better than
the slit between two fingers.

1. Tape together two large nails.  They are not exactly
straight, and can be taped together with a very small
slit between them.  This is awkward, but is useful for
experimenting with small slits.  (The same effect could
probably be done with flat-edged calipers)

2. Take a small piece of window screen (six inch
diameter).  Fold several times.  I used three folds
for a pie-shaped piece with eight layers.

3. Take a 1.5 inch by 2 inch Post-It note.  (Yes, I
used a 3M Post-It for 3-D)  Place on suitable surface
and with a razor blade or utility knife cut many
parallel slits.  I made them about 1/16 inch apart,
although closer together would probably work better.
Put them as close together as you can..you can keep
making them until you find the right dimensions.

I prefer Number 3, the 3-D Post-It.  I just stick it
on the lens of my right eye, but I sometimes have to
wriggle it a bit to make the slits open up just right.

Number 2, the screen filter, seems to work with the
least adjustment.  Photographers might try a star
filter.  Nylon or woven fabric might also work.

Anyone have a diffraction grating handy?  I suspect
a dark filter over a diffraction grating might work.

How about one dark polarized lens?

As you might expect, the animated backgrounds and
closeups have the most extreme 3-D effects.  The
planet/star background and rotating cards are my
favorites for testing.
-- 
Scot E. Wilcoxon  sewilco@DataPg.MN.ORG    {amdahl|hpda}!bungia!datapg!sewilco
Data Progress 	 UNIX masts & rigging  +1 612-825-2607    uunet!datapg!sewilco
	I'm just reversing entropy while waiting for the Big Crunch.