Infinity window

[P3D Paul S. Boyer <boyer@xxxxxxxxxxxxx>]

IMHO Gregory J. Waheman is correct, that the lenses in a stereo

camera are moved very slightly inward in order to place the stereo
 
window.  Several publications have diagrams illustrating the

geometry which makes this necessary.  The lenses are not really
"toed in," but are simply slid inward (by translation, not rotation).


In the earlier days, there were some stereo experts who recommended  
the "infinity frame" which results from centering each lens over     
each half of the stereogram.  According to my notes, they included

L.E.W. van Albada  (1931.  Stereographie, in Handbuch der

wissenschaftlichen und angewandten Photographie, Bd. 6, Erster Teil,

pp. 1-101. Wien) and A. von Barsy (1943.  Raumbild-Photographie;

Technik und Gestaltung der Stereoaufnahme, 108 pp., Halle an der

Saale).  See also W. L. Bergssenbrugge, 1948, "Framing the image in

the stereoscope," American Photography vol. 42, no. 5, pp. 276-279;

no. 6, pp. 350-354.


I seem to recall that the taking lenses in the Macro Realist are
moved closer inward than in normal Realist-format cameras, in order
to place the window closer than the 2.1 m standard for the regular
Realist.  Check it out if you ever see Macro Realist.
--Paul S. Boyer  <boyer@xxxxxxxxxxxxx>


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