P3D Re: digital pointer and other stuff

["Dr. George A. Themelis" <DrT-3d@xxxxxxxxxxxxxxxxxxxxxxxxxxx>]

Ron Labbe wrote:

> I remember when you thought a Realist wide angle adapter or RBT stereo
> camera was unnecessary/ too expensive... 

And who says I've changed my mind?  :-) :-) :-)  The Realist wide angle 
adapter is still unnecessary for me.  And the RBT stereo cameras are 
too expensive!

"Unnecessary" is in the eye of the beholder.   As I have said countless
times, going from 2D to 3D with a $100 Kodak or Realist, is a
tremendous leap.  From there on, you pay a lot of money for small
improvements.  But those who have the money and want to have an
edge, equipment-wise, will take the step anyway.  Will they produce
better pictures?  Not necessarily!

Now, regarding the digital pointers, is Jon Gross still in this list?
I remember when he showed me this educational/medical system, three
years ago, there was a stereo pointer associated with it.

To be honest, I have never seen anyone use a laser pointer in stereo
projection, so I doubt that people will wake up wondering how they
could have been projecting all these years, without a *stereo* laser
pointer.

The thing I have seen and used that is the closest to the idea of a 
stereo pointer is the "floating point" in photogrammetric measurements.
The stereo pair is positioned under a large mirror stereoscope.
A "parallax bar" is placed under the pair.  A micrometer controls
the spacing of two glass plates at the end (one is moveable).  A
small cross or circle is etched at the plates.  The bar is adjusted
so that the point formed by the coincidence of the marks is at a given
depth level.  The micrometer indication is recorded and the bar is
adjusted for the floating point to mark another depth level.  The
difference in the micrometer readings is the parallax.  This is
plugged into a formula to give the true difference in depth between
the two points.

George Themelis


------------------------------