From: SFPhysics@aol.com
Date: Sat Dec 18 1999 - 08:03:05 PST
From: SFPhysics@aol.com Message-ID: <0.1bbc482c.258d0a39@aol.com> Date: Sat, 18 Dec 1999 11:03:05 EST Subject: More 3D!
Eric:
One other thing about projecting a 3D image, image alignment is CRITICAL.
The images have to vertically be identical or the viewer gets an eyestrain
headache. For this you simply use the projectors thumbwheel to move the
image up or down. Horizontally you want the farthest object away to align,
the 3D effect is done in the human brain by the nearest objects being out of
position in relation to the single point references in the background. Do
this with glasses off and pick a good set of slides where the background
images are identical. Stereo slides taken by a single camera will not be
100% on target horizontally but the eye compensates reasonably well,
horizontally. Both images should be of equal brightness, old bulbs get
dimmer as they get used, and identical projectors helps. Use the same
polarizing film for both projectors and the best place is in front of the
lenses. Make sure with a pair of polarized glasses that you have the left
and right image in the correct projectors. Turn on only the left projector
and only the left eye should see the light. The 3D glasses are cheap and
some light will get through the right eye. Good projectors have heat
absorbing glass in the source focusing system. A cheap projector will melt
the polarizing plastic film. All Kodaks are OK. Lastly, the source for 3D
materials mentioned by David Fryman is at:
http://stereoscopy.com/reel3d/projection.html
There are more than the two sources mentioned but these are a good place to
start. I know I am forgetting something but at my age cannot remember what.
;-)
Best again to the list,
Al Sefl
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