Re: Composing for window effects

[P3D Dr. George A. Themelis <fj834@xxxxxxxxxxxxxxxxxxxxx>]

Grant writes:

>I'm trying to use my grey cells to figure out if the centers of the
>aperatures are shifted toward each other or away from each other.  
>Can you help me out?

Some way you would shift a mask to create a stereo window in a pair where
the window is at infinity (or beyond).  To push the window forward you need
to bring the chips closer together, or the masks further apart.  So, the
camera apertures are shifted away from each other.

>And by aperature, you're not talking about the f/stop openings, right?  
>You're talking about the aperature against the film, the frame aperature?  

Right.

>Doesn't this shifting cause keystone distortions?  

No, only tilting will cause keystone distortion.  Not parallel shifting.

>Does the Kodak have this same shifted aperatures as the Realist? 

Yes.  I think all stereo cameras have a stereo window built in at about 7
feet.

--- George Themelis

PS.  I think the correct spelling is "aperture" and not the commonly used
"aperature".   Also, some people insist in writing "lense" instead of
"lens".  None of the two words is Greek so take my word with a grain of
salt (hmmm... that margarita sounds more and more appealing in a slow
Friday morning... :-) )


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