[MF3D.FORUM:418] Re: fl/30

[Tloc54452@xxxxxxx]

In a message dated 2000/04/05 20:47:41, koganlee@xxxxxxxxxxxxx writes:

>This, by the way, seems to be the opposite of the PePax principle which
>McKay used to try to cancel 2 deviations with each other. He increased
>the stereo base in exactly the same proportion as the focal length of the 
taking
>lens was increased (p. 61 of Three Dimensional Photography by Herbert
>McKay). However, he was not concerned about on film deviation, only with
>making the distortions cancel each other (which, of course, is impossible).

In fairness, he wasn't the only one making this error.  Binocular gurus
were saying the same thing.  Maybe McKay got it from them.  Binoculars
are stereo systems too - they have a taking lens, an image, and a viewing 
lens.  But they can't be ortho if they have any magnification.  It's 
interesting
that even telescopes exhibit squash.  Monocular squash is numerically
equal to stereo squash, so they cannot and do not conflict.

John B