P3D Re: Cardboarding

["Greg Wageman" <gjw@xxxxxxxxxx>]

From: Bob_Maxey@xxxxxxxxxxxx <Bob_Maxey@xxxxxxxxxxxx>


>CARDBOARDING: Under what specific conditions is everyone seeing this
>effect? If you take a photograph using a stereo camera, everything in the
>scene will have depth. Granted, not much in the mountains in the
>background, but even there, there is stereo separation - however slight. So
>what some are describing as cardboarding is unclear (to me anyway).


I often encounter it in stereo prints.  I've run into it in ViewMagic over-under
prints, and in Holmes card format prints (including some of my own).  I can't
recall seeing it in slides.  I haven't looked at any VM reels recently enough to
say whether or not I've seen it there (with "real" images).

That isn't to say that it cannot occur in transparencies, just that in my
experience it usually doesn't.

>In some images such as many VM reels, the effect described as
>"Cardboarding" happens because some of the props in the image as well as
>the actors in some cases, actually have no depth


This is true, but this isn't what we're talking about specifically.  We're
talking about an effect that sometimes occurs that gives real scenes the
appearance of those reels you mention.  That is to say, you can see that the
objects in the scene are at different depths, but the objects themselves all
appear to be flat (when we know that they were not).

I attribute it to insufficient resolution in the viewed image to allow
stereopsis to occur within the objects.  This is not the same as a lack of
parallax; in this case the parallax may exist, but the brain is unable to
correlate homologous details on the objects to produce a sense of shape.

It's possible you've never seen it, or at least never noticed it.

     -Greg W. (gjw@xxxxxxxxxx)




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