P3D Keystoning - mea culpa

[David Spacey <spacey@xxxxxxxxxxxxx>]

Hi All,

George T corrected my comments:-

>>Assuming the ol' 1 in 30 rule, for the sake of
>>argument, that puts the closest object 900 feet away.  The perspective
>>distortion at that distance will be zero to as many decimal places as
you
>>like, surely?

>Hmmm, not really.  Ever heard of "similar triangles" :-)  It does not
>really matter if your subject is 900 or 9 feet away.  If you double the
>distance (from 900 to 1800 or from 9 to 18) sizes are cut in half.  
>It is a matter of ratios. 

Good point, I obviously hadn't thought it through properly.

OTOH at 1 in 30 the cameras are toed in fractionally less than one degree
each.  (I *can* do this geometry thing really  ;-)  Boris uses more toe in
than that, and when challenged we all found it difficult to see any
keystoning reliably.  It could still be OK.  Certainly worth trying it,
and see what the results are like.




Dave Spacey
____________________________________________________________________________

Walk tall, walk straight,
Spit the world right in the eye.

-Kevin Godley and Lol Creme


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