The above is what is called a stereo pair. Two images are
taken from positions about the same distance apart as the human eyes and
arranged in such a manner as to allow us to merge the two and create a 3-D
image approximating what the original scene looked like. This is the peg board
in my wife’s sewing nook.
This is where 3-D gets a bit complicated. First you have to
realize that normally everything we see is in 3-D. When we take a picture of
something we reduce it to a 2-D image. To see a 2-D image in 3-D we have to
re-establish its depth artificially.
The best way to accomplish this is to take two pictures
simultaneously from two different locations in the same horizontal plane
located from 65mm to 75mm apart. This is the average distance between the eyes
of humans.
Next we must view those two images in such a way that the
right eye looks at the right image and the left eye looks at the left image, thus
imitating and re-establishing the original spatial relationship between the
objects in the images.
If you stare at the middle of the two images above for a few
moments and allow your eyes to refocus a third image will form in between the
two images and will be in 3-D. I am told that only about half of all people can
do this naturally. It is called “freeviewing.” Everyone else must use some kind
of viewer. Try it and let me know if you can "see it" in 3-D.
There are a great many stereo or 3-D viewers that have been
developed over the years. Some are for use with photographs while others work
with slides, or transparencies. The Viewmaster discussion (see earlier blog post)
that introduced this whole 3-D topic represents what is probably the most
widely known and popular stereo slide viewer ever made. Millions of these have
been sold since I was a kid and they’re still available these days. In fact I
just bought one.
More recently of
course people are interested in viewers that can be used to see 3-D images with
stereo pairs displayed on the computer screen. The new Fujufilm Fine Pix 3D W3
digital camera has a display screen which shows a 3-D video
lenticular image. They also have a “tablet type device” that displays the same
image except on a 7” screen.
Lenticular photos are also available from Fujufilm (for a
price of course) using the uploaded digital images produced by their new 3-D
camera and there is at least one film processor in Canada that also produces
lenticular prints from film.
Many of these cameras & viewers, including the
Viewmasters are available from www.3dstereo.com.
If you want to see the things I’m talking about here check out their web site.
www.Stereoscopy.com is another
interesting site on this subject.
In my next blog post I will discuss and demonstrate how to
take stereo pictures and create stereo pairs to actually see your own 3-D
stereo images.
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