P3D digital camera 3D capture by multi recording

["Stuart Stiles" <sstiles@xxxxxxx>]

	There have been several reports of sightings of unintentional stereo pairs
in newspaper and magazine photos. This is the first time that I have heard
of the capturing of an unintentional 3D image by a photographer who was
using the multi function on a digital camera.

	Jan Berlin does programs about animals for school children. After visiting
an exhibit featuring the viewing of 3D images that I had set up at my
campus, she wanted to use 3D viewing in her work with the children. She has
a couple of my 3D Book Viewers, an explanation of how to take stereo photos
with a homemade rig, and a few stereo pairs.  She is looking for additional
photos of pets, if any of you have such photos. She also has a curiosity
about the arts and sciences that leads her to explore new ways of looking at
things. I am not surprised that she experimented with the photos that her
friend sent her.

	In response to her excited e-mail, I attempted to explain how her stereo
pairs might have been produced.  I have not actually seen the images, but I
know that she understands how to move the photos around to bring out the
stereo effects.  If you find my explanations a bit weak, or in error, I
would appreciate your thoughts. If, as I am sure some of you will do, you
attempt to replicate her friend's results, please share your findings with
us.

	Here is her letter to me, followed by my response to her.


-----Original Message-----
From: Jan Berlin [mailto:janimals@xxxxxxxxxxx]
Sent: Wednesday, January 19, 2000 12:43 AM
To: sstiles@xxxxxxx
Subject: P3D something interesting


Hi,
Thanks again for dropping off the 3D Book Viewers.  I just sent your
email address to my best friend in Detroit and she will be contacting
you about placing an order.  She works with elementary kids in after
school enrichment programs and is very interested in doing something
with your book viewer.

Yesterday evening a friend emailed me a 9 photo montage of her dog that
was taken with a digital camera (Sony Mytek or Myvek(sp?) 71). With just
one touch of the button she was able to snap nine photos in a row in
just a few seconds. Because the dog didn't move much each photo had only
the most subtle of differences. I printed off the photos and when I
placed the viewer between two photos of the montage - voila! I got a 3D
image!!  I asked her to bring the camera to my house so that I could get
pictures of my pets in the same fashion.  They came out even better than
what she sent me due to more light in the room.  If you don't have a
digital camera you must borrow one that has this feature so you can see
how cool this is.  In the manual it is listed under "Recording - multi".
The photos go right onto a floppy disk that is placed in the camera and
then into the computer.
She now has the same assignment that your group has - to get me nature
photos by the bunches!

Thanks again,

Jan Berlin

---- Reply by Stuart Stiles-----

"Jan:

	There is a technique for taking stereo photos with a single lens rapid
fire, or automatic advance, camera.  We call it "cha cha" because it
involves a slight movement that is similar to the cha cha dance step.  Put
your weight on your right foot when you take the first photo, then shift
your weight to your left foot before taking the second photo.  The problem
is that this technique works only with stationary objects.

	What you have discovered from images produced by the SONY Mavica
.. and I believe that I am using the right term there.. "discovered".. is an
effect similar to that which we get with the Pulfrich technique in
videography.  By steadily moving the camera to the left you produce an image
in which the scene slowly appears to move to the right.  When viewed through
a pair of pulfrich glasses (clear lens on left, darkened sunglass type lens
on the right) your right eye sees the image that just passed by, while your
left eye is seeing the image that is actually "present." Two differing
perspectives of each object will result.  Pulfrich viewing is a bit hard for
the brain to digest, but the technique works. You need to adjust to looking
at images that have retinal rivalry in brightness. You may also get tired of
looking at the scene after a few minutes.

	Your digital image technique is much easier to view, because it uses fixed
images that represent changes in perspective produced by the movement of the
animals and the photographer. Those fixed images are viewed by the more
standard lens system of the 3D Book Viewer.

	Want to try something that is based on the "Magic Eye" technique?  You
mentioned using single image stereograms.  If you can view them, try the
same technique of "parallel viewing" with one of the images in the STEREO
WORLD magazine that I gave you. You may be lucky enough to see the three
image display immediately. One of the images will be in 3D.  If not, with
some practice, you will notice that you see a double image of the stereo
pair photo. That will be four images.  Stare ahead, move the magazine page
so that the doubled images align horiozntally, then move the magazine, or
relax your eyes while continuing to look past the page, until the right
image of the left pair and the left image of the right pair overlap.  You
will then see three images.  The center one will be in 3D.  If you perfect
that technique, you will no longer need to buy any of my viewers, except for
the purpose of showing the children what they are supposed to see when
"freeviewing" as described in this paragraph.

	Thank you for sharing your discovery.  If you don't mind, I would like to
share our e-mails with the Photo 3D list.

	Welcome to the world of stereoscopic images."

---- end of reply-----


	Jan gave me her permission to pass along the e-conversation.  She also
asked that you contact her, if you have any "animal pet" 3D images for her.
Her e-mail address is in the heading of her letter above.

				Stuart

					http://www.orn.net/~sstiles