Stereo Window

[P3D Dylan The Hippy Wabbit <spacey@xxxxxxxxxxxxx>]

Hi,

First I'd like to say thanks to all who have contributed to the discussion
of the stereo window.  Being new to stereo I was just marshalling my
thoughts to ask about that myself.  It's been very helpful.

Secondly I've come across a web site with a useful discussion of the
subject at http://www.werple.net.au/~kiewavly/beginner.html.

Now this caused some confusion for a while because thier discussion
concentrates on what happens at the edges.  How the left eye sees more of
the right-hand edge, and vice versa.  On the other hand your discussion
has mostly been about the 'plane of coincidence.'  I think I've got it
sussed though.

Now this may seem obvious to you old hands, but the thought came as a
revelation to me.  In an uncropped stereo pair the stereo window is
optically *at infinity.*  That is, only distant objects are in the same
position in each frame, and every foreground object is apparently closer.
So the object becomes to crop so that the closest object is in the same
place in each frame if it is required to be level with the stereo window.
To move it behind the window it then needs to be moved so that it's left
image is closer to the left edge of the frame than the right one.

As for the stuff about whether the window is moving forward or the image
moves back doesn't that depend on whether the frame is moved or the images
behind it?

Correct me if I'm wrong, but that seems like a useful summary to me.

Dave Spacey

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