P3D RE: P3D Pulfrich

[Adamson D <D.Adamson@xxxxxxxxxxx>]

> Dave Spacey wrote in reply to Dave Combs
>
>Are you sure one eye is a whole frame behind the other?  Only if the
>filter is dark enough to add exactly 1/30th of a second to the time to
>process.
>

I must admit that when I write this, I can not remember the exact (simple
level) tech. specs. of the NTSC system used in America. Here in the UK we
use PAL at 25 fps, HOWEVER each frame is composed of TWO fields (one for the
odd and one for the even lines on the screen).
When recording most cameras will use an updated version of the picture as
the source for the second set of lines. Whilst the first set of lines will
still be 'visible although fading', this does mean that a delay of only 50th
of a second is reqd. from the glasses. 

David Adamson.

p.s. I have used _supplied_ grabbed images (at a high enough resolution to
be practical) that contain both fields 'interleaved', as a source for 2d-3d
conversions. There was sufficient movement (of the appropriate objects) to
generate the background material appropriate for each eye. (I hope this
paragraph is clearer than I sounds to me!)


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End of PHOTO-3D Digest 3113
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