Re: Vertical misalignment

[P3D John Bercovitz <bercov@xxxxxxxxxxx>]

BobH writes:
> I still need convincing on why a tilted stereo camera with one lens 
> higher than the other is not like a rising front on a view camera and 
> changes the field?  Is it because the FRAME moves too when you tilt 
> the stereo camera?  

Sure you have vertical misalignment, or more properly vertical parallax, 
_within_ the chips if you tilt the camera.  This is easily confused with 
a vertical misalignment _of_ the chips which occurs in mounting or if 
the lenses of the camera are level but the gates are not (one gate higher 
than the other) and this is not corrected in mounting.

If you correct for one camera lens being higher than the other by 
rotating the film chips back to vertical, you will see vertical parallax 
within the chips.  If you just mount regularly (and for equanimity tilt 
your head when you view, the way the camera was tilted when you took the 
picture) you won't have any vertical parallax.

> would the vertical parallax result in any  kind of stereo resolution? 

There was a thread not too many years back about stereo resolution
due to vertical parallax.  Maybe Jim C can refresh our memories.
Seems like there was some speculation that it existed.

John B


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