P3D Re: 3d shadows in Detroit

["Dr. George A. Themelis" <DrT-3d@xxxxxxxxxxxxxxxxxxxxxxxxxxx>]

>>I took a picture of my shadow in the steps of my workplace... 
>>I ended up reversing the image (R chip to L and L to R).  That did 
>>not alter the shadow but it did change the shape of the steps. 
   
>I do not understand how a shadow 
>behaves differently than say an image painted on the steps. 

It does not.  What has really changed are the steps.  They
do not look like the dirty, ugly steps any more. The picture 
was taken at a slight angle and the linear perspective of the 
steps converging at infinity has been reversed and it looks
as if they diverge with distance.  You cannot tell that you
are looking down any more.  Looks like you are looking straight
and the shadow is formed in some kind of unsually textured
surface.  Perhaps John Vala, one of the judges during the
competition and photo-3d member, can tell us what he thought
when he saw it.

>I am also interested in seeing a sample of the 3d shadow of a 2d 
>image effect you mentioned. I am having trouble visualizing the result, 
>does the 3d shadow appear to be in front or behind the 2d image?

The flash was behind the object and the shadow was falling between
the object and the camera.  When mounted properly the shadow
is formed in front of the object, towards the camera, so it can
be made to go through the window.  We got the idea from a book
(I forget the title right now and cannot find it around) that has
an anaglyph of the shadow of a chair leaping out of the window.

These are interesting concepts, worth experimenting with.  I am
glad that this Detroit assignment gave me the opportunity to 
try my hands on them.

George Themelis


------------------------------

End of PHOTO-3D Digest 3243
***************************