Re: [photo-3d] Base Calculator

[Herbert C Maxey <bmaxey1@xxxxxxxx>]

WARNING: The following is based solely on my narrow view and my aversion
to formulas that are too technical as to overly complicate the simple
process of Stereo Photography. Remember, I am the Old Fart Curmudgeon, so
please, no e-mails telling I am full of beans - I can't be retrained at
this late stage in my evolution.

First of all, Stereo Base Calculations are OK, but one should never
overlook the idea that separation approximate to G.N.I.S - 2-1/2 inches
or so  (God's Natural Interoccular Separation) works well for 90 percent
of subjects. I have seen a few of these and they all seem to disagree
with the other formulas I have seen. When 2 formulas disagree, I become
suspicious as to their value altogether. NOT any sort of comment on the
above poster's formulas, by the way.

I only worry about this when shooting macro stuff. In that situation, all
formulas go out the window and I wing it. I am sure that if I figure it
to the millimeter, I would find differences from slide to slide. I use
the Nudge Formula: The smaller the object, the less of a nudge I have to
use. 

Do not overlook that a millimeter is very small, and serious tests would
reveal that you, me, most of us would find little difference in the
viewed image even if you were to change say a millimeter from slide to
slide. If I am photographing subjects measuring 1 or 2 inches in size,
filling the frame, and I shoot one with some arbitrary separation and
then took one with slightly less separation and a third with slightly
more separation, you would be hard pressed to find much difference. There
would also be no way you could telll which one is correct.

Then there is the mounting considerations what add another factor. 

Bob