P3D RE: Alignment of seperate 35mm Cameras...

["Johnson, Stuart" <SLJ4@xxxxxxx>]

        George T.,

          Thank you for your explanation of Diverging,
Converging, and Parallel axes.  I guess my initial research and
work in the field had not solidified these exact concepts very
well.  From what I had read (and I assume correctly used) I
have been using the PARALLEL axis technique.  This is why
I was originally puzzeled when folks were talking about the 
converging axis principal.  The terminology you chose was 
most appreciated too, as I guess I had been taking some
liberties with my description of my observations. (Oooops)

        O.K.... So I'll return to Parallel shooting, but I think
what I observe may be happening is that when shooting 
parallel axis, that the stereo window is PARALEL to each
camera's film plane.  But when the camera is adjusted to
where the effect is Converging at some point before
infinity,  it appears that the two seperate lenses see the
exact point of convergence, but that the stereo window is 
only the same at this point. The Right lens film plane
on the LEFT side of the film would see an object to be
farther than the what the Left lens would see its LEFT
side. The opposite would occur for like information on
the Right side of each lens's film planes.  My experience
seems to indicate a more "pleasing" and "sharper"
stereo window (3d area) when the stereo windows is
exactly parallel with each cameras film plane. This seems
to be logical to me as our eyes do not appear to be 
fixed at a convergence (like two seperate cameras would
be), but set straight ahead.

>>      -Is the "fixed mask" designed to crop a little more
>> of the left side of the right image, as well as cropping
>>  a little more of the right side of the  left image?
>> (or visa-versa as you move it around the pair)

and...

<<<There are many good books out there, explaining the
<<< concept.  I liked  the "3L" rule that says:  "The Left
<<< eye sees Less in the Left side"

        -Would you mind going into a little more detail on
 the above? I do not use a "mask", but instead use a 
hooded viewer without the long focusing bar (I cut it off)
and just move the picture until they appear to be at the
optimum position for cropping/mounting. (as opposed to
just cutting an exact amount off of each image with 
something like a mask)

Once again George, I appreciate your information a LOT.

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

PS-     HOLY GREAT TIMING!    Imediately after my last
request on Stereo Clubs in Sacramento, the RANCHO 
CORDOVA CAMERA club happened to be having a
meeting later that night (I missed it).  But PAULINE said
they have a strong Stereo group, and were having a
competion & show that night (I'll catch a repeat of it Sunday
I hope).


                        Thanks for the time,

                                -Stuart Johnson
                                Sacramento Ca.
                                GCSPHOTO@xxxxxxx


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End of PHOTO-3D Digest 2769
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