Re: requirements for a new camera

[bercov@xxxxxxxxxxx (John Bercovitz)]

Dick Twichell writes:

[...]

> A question:  with John B.'s suggested displacement of 2.25mm, would there
> be visible keystone distortion due to this offset?  [...]

Keystone distortion comes from not making the lens axis perpendicular to
the film plane.  In the present case, stereo cameras, the situation is the 
same as shift, rise, or fall and is not like swing or tilt which do cause 
keystone distortion.

>   I am not sure if Piper means
> displacement for each lens off center, or the total of both.

He must mean to measure the distance between the centers of the film gates 
and subtract the distance between the centers of the lenses.  That would
give the window distances you quote.  Somewhere bobcat has a listing of all
cameras' measurements which Alex Klein did.

John B


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