http://www.youtube.com/watch?v=4eTH69GNX_0
http://www.youtube.com/watch?v=p-HK9ubIEL8
http://www.youtube.com/watch?v=DtPnMzNh2Zs
http://www.youtube.com/watch?v=OHYmY7lw3nQ
The Pulfrich 3D group on Facebook…
http://www.facebook.com/group.php?gid=10788759479
From WIKIPEDIA…
It sounds alot fancier than it really is: Get a buddy to drive a car about 10 MPH along a suburban neighborhood where you have things (trees, fences, houses, etc.) both near the road and far away from the road. Your job is to sit in the front passenger seat, hold the recording video camera steady, and just point it out the right window, perpendicular to the direction of travel. Then rush back home and watch the video with only the right eye covered by sunglasses (I used polarized flip-down shades, but polarization has nothing to do with it) and you have Pulfritch 3d ! I saw my first homemade Pulfritch at the 1989 NSA Convention in Portland, OR, which was taken out the side of a Disneyland monorail.
The reason: Things closer to the camera will move faster across the TV screen. The dark lens on the right eye reduces the scene’s light intensity to the right eye. The brain takes longer to process dark scenes. So, by the time the brain has processed the fast moving tree in right eye’s scene, the left eye’s tree has already moved farther to the right. To focus the tree the eyes must cross more, thereby giving the illusion of a closer tree. So, with the dark lens on the right eye, things that move faster to the right appear closer, and things that move faster to the left appear farther away.
Prove it: Hang a spectular reflector (like a metal spoon) in the center of a doorway with a string. Swing the spoon side to side like a pendulum (always same distance to you). With the dark lens on your right eye, the spoon will appear to swing in a circle: closer to you when moving to the right, and farther from you when moving to the left (counterclockwise from above). Move the single dark lens to your left eye and the spoon will now appear to swing clockwise from above.
Mike Watters adds:
Rotation (ie having the CAMERA spin around) doesn’t work. If you think about it briefly, you’ll see that the camera’s orientation never changes in relation to the subject(s) so their isn’t any source of stereo information. However having the SUBJECT spin around, like the Ukranian skater (you’ll have to forgive me for not trying to spell her name) in the olympics, the bed in the “magic bed” video or in the goldilocks and the 3(-D) Bears video, works fairly well.
The foreground (moving from left to right) will appear to be in front of the screen and the background (moving right to left) will appear to be behind the screen.
Moving the camera sideways (ie stick it out the side window of your car as you drive) also works well. In this case everything is moving left to right (if you stick the camera out of the right-hand window) and will appear to be in front of the screen. Since closer objects will move across the screen faster, they will be more “in front”.
For a handy-dandy preview, put on your pulfritch glasses next time you are in the car (hopefully as a passenger) and look out the window as you move along. The world will look like it’s in hyper-stereo. I can’t recall who on the list originally posted about this last suggestion, but I tried it and it works great. I guess what I SHOULD have tried was putting the glasses on backwards and having a peek at “pseudo-world”. :)
Oh, one final note: Since the effect works off motion (I think the dark filter must be having some sort of effect on persistance of vision, in terms of a mechanism) only objects that are in motion on the screen will show any stereo. Thus; the skater will appear fully 3D when shoe spins (with a flat background), while as she skates sideways both she and the background will be flat but seperated from each other (the infamous cardboard-cutout effect).
http://www.photo-3d.info/wiki/Pulfrich_Effect
