[photo-3d] Camera separation in stereo photography

["Dr. George A. Themelis" <drt-3d@xxxxxxx>]

>> Saturday 4 PM
>> David Lee
>> Camera Separation in Stereo Photography
>
>Will full body armor be provided, or should we bring
>our own?  ;-)
>
>If it's anything like P3D when this topic is discussed,
>perhaps the riot police should be alerted and standing
>by on-site.  ;-)


You have to take into account who is giving the workshop.
A person with lots of personal experience on this subject
and no religious convictions about it.  I think it will
be a great educational experience and I am planning to
attend!!!  (We've only had problems in P3d when the
dangerous combination of personal philosophy and
mathematics has taken over the art of stereo photography :))

I remember this topic coming up in the 3D Window, the
excellent newsletter of the Sydney Stereo Camera Club.
Unfortunately, I cannot find the specific copy right
now (Ray Moxom, the Editor, can correct me if I am wrong)
but I seem to remember that someone concluded that
there is no such thing as "optimum separation", a
theory to which I always subscribed.  In the following
issue, a letter by Steve Spicer (of the famous "Spicer
Mounts", carried by RMM) replied by saying that there
is such an optimum separation and this is the spacing
of the eyes. (I might be oversimplifying here, so Ray
please correct me).

I thought this was a VERY interesting concept.  There
is only one frame of reference for us humans.  This is
the spacing of our eyes.  In one sense, this is the
"optimum".  But when you have your subject too far
or too close to the camera, it is better to increase
or decrease your stereo base.  The minute you deviate
from this "optimum", there is no way to define the best
stereo base... There are different formulas that give
different answers, depending on what you are trying
to achieve.

In the MF list recently, one member, new to stereo
photography, was wondering about the optimum stereo
base and he shot a lot of pairs with mixed results
(apparently, there was some problem with mounting
that caused complications).  A lot of helpful
discussions and formulas and spreadsheets were discussed
in an effort to help this guy.  My approach to this
would have been different.  I would say to the beginner:
"What is the spacing of your eyes? 65mm?  OK, then
use this as your stereo base".  If you clear objects
within 7-10 feet from your camera, you should end
up with perfectly acceptable stereo pictures and that's
a good way to get started.

George Themelis