Question for printmakers

[P3D Dr. George A. Themelis <DrT-3d@xxxxxxxxxxxxxxxxxxxxxxxxxxx>]

Greg Kane asked if the maximum infinity point separation (IPS) of 
prints should be equal to the lens' spacing of the lenses in a 
stereoscope.  Alan Lewis responded:

>Answer: technically yes.  
>[...] As far as I know there is no ideal IPS. Antique views used 
>different standards for infinity separation, and for window placement.  
>As long as the max. inf. separation on your view doesn't exceed the 
>optical centers of those particular lenses then viewing should be 
>comfortable.  

The same questions/answers can be given for viewing slides in a
slide viewer.

My question:  Why is it that slide makers pay so much attention to the
placement of the stereo window while print makers appear to have
basically neglected it?  I am not very familiar with contemporary
print making but this is the case in antique stereo prints that I
collect.  In most antique views the window is placed *beyond* infinity!

Is it that in prints the window is not as important as in slides?
Is this a fact?  Why?

George Themelis


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