P3D 3D video systems

[Marvin Jones <Campfire@xxxxxxxxxxxxxx>]

Message text written by INTERNET:photo-3d@xxxxxxxxxxxxxxxxx
>>I vaguely remember reading somewhere about a device used to convert an 
ordinary camcorder into a 3-D camcorder by splitting the lens. Has 
anyone here used one of these? Was I hallucinating it all? How would the 
proper signal get encoded onto the video tape?
How much do real 3-D camcorders cost?
Also, are most 3-D video tapes compatible with different kinds of signal 
boxes/shutter glasses?<<

You are probably thinking of the Nu-View lens, which is not a
"beam-splitter" but an alternate-field attachment that will fit most modern
camcorders. Further information is available at
http://www.3dstereo.com/f-nuview.html. Although there was one goofy attempt
at split-screen 3D in video a few years ago, virtually all serious 3D video
currently involves some kind of alternate-field system. Briefly, although
NTSC video is quoted as running at 30 frames per second, the TV screen is
actually refreshed 60 times per second. For it to work mechanically, every
other line of the screen image is drawn in 1/60th of a second, and then the
alterate lines are filled in, making for one complete image in 1/30th of a
second. 3D video exploits this by putting the left and right eye images on
ALTERNATE lines of the image. Viewed through glasses synchronized to the
image, one eye and then the other are blocked by an LDC lens, allowing each
eye to see only the odd-numbered or even-numbered lines. The Nu-View
attachment creates such an alternate-field 3D signal. So did the old
Toshiba 3D camera, which was a rarity even in its heyday and has become so
sought-after today that people are actually asking as much as $12,000 for
one (asking, mind you, not necessarily receiving). Given improvements to
camcorders in general, the Nu-View system is probably as good as, if not
better than, the Toshiba. All AF video works on the same principal, so
tapes are playable on just about any system. The only caveat is that some
tapes reverse the fields used; in other words, some use the odd-numbered
fields for the left image, and some for the right. Most viewing systems are
easily switchable, however. Hopefully this will answer most of your
questions.



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