P3D Re: telephoto depth?

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

>>I'm wondering how the apparent  "squashing" of depth that a telephoto lens
>>produces (in 2D) would affect a stereo shot?
>    
>It would be the same for a stereo shot. That is, the image would looked squashed
>when viewed with a normal viewer that has a shorter f.l. viewer (compared to a
>telephoto lens on a camera). If you match the viewer and camera lens f.l., the
>image won't looked squashed or stretched but rather ortho Correspondingly, if your
>viewer has a much longer f.l. than the camera, then the image would look stretched.
>Hope this helps.

In addition to what Gabriel said, let me add that, depending on the shot,
as a result of this squash, you might also get a "cardboard cutout effect" 
where objects (especially people or animals) look like cardboard cutouts 
instead of real objects.  It is usually recommended that you increase your
stereo base accordingly, i.e. if you use 135 mm lenses (45 mm x 3) increase
the base to 7.5 inches (2.5 inch x 3) to reduce this effect.

George Themelis


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