Re: Stereo with your SLR!!!

[P3D Larry Berlin <lberlin@xxxxxxxxx>]

It turns out with a little experimentation in TrueSpace that it isn't
possible to achieve ortho-ness with the two mirror system for any object
whose visible image is greater in size than the interocular distance. This
is because at an angle to provide a full image in each mirror, there is a
minimum separation between the centers of these images matching the apparent
size of the object. This forces the effective observation points from the
two mirrors to be of a hyper-stereo perspective for many objects.

If you like stretch, it may not bother you. For devices with more mirrors,
such as the *beamsplitter*, this is not a problem. If one gets used to the
effect, it is actually enjoyable. The context of the usage will determine
whether or not it *works*.

Obviously if you use a wide angle lens, or are far enough away from the
object, the apparent image size is reduced and orthoness could be achieved
with a typical subject such as a person's head.

Others on this list could probably come up with the formula that matches
object size, perspective, lens length, and distance to the camera to obtain
actual orthoness. This may not be necessary since *beamsplitters* already
exist and would make it relatively easy to circumvent this problem.

I am preparing some images that help illustrate this situation and will post
it on the web soon.

Larry Berlin

Email: lberlin@xxxxxxxxx
http://www.sonic.net/~lberlin/


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