…but woodworkers are curious and clever, so I figured that if anybody would know, it would be you folks.
Remember when kid’s books had moving pictures? As you moved the page, a picture would flip back and forth between two views. There was always a striated layer of clear plastic over the picture. Do you know how do they work?(–or just what they are called, so I can Google it.)
I’d take one apart and figure it out myself, but it’s been years since I’ve seen one. Then I came across a table that has a moving design:
http://melbournearchitects.blogspot.com/2010/12/magic-carp-pet-rug-design.html
(click on the video)
and I wondered if it worked the same way as the kid’s books, with striations in the glass table top. Any ideas on how to research these moving images?
Janet
Replies
kids books and optical illusions
Older children's books had "pop-up" figures that were based on the difference in geometry when the book/page were folded/closed vesus open. More recent books used printed holograms or striped images viewed through a fresnel covering, giving different views from different angles. The coffee table function appears to be based on moire pattern optical illusions.
I think you might be referring to hollowgrams. I think the slats on the table fill in the voids in the rug figures, giving the illusion that you see movement. You actually are just seeing the voids filled in from a different perspective as you move. Not sure how effective it would be in real life, interesting, though.
Much older technology
Hammer1,
I don't think they were holograms, which are made with lasers. I remember the pictures from my own childhood, and that was before electricity!
Janet
I remember some album covers, the Rolling Stones, Satanic Majesty's Request, for one, that had what I think you are talking about. Which led me to the correct name, lenticular image.
http://en.wikipedia.org/wiki/Lenticular_image
jyang,
I remember the pictures as prizes from Crackerjack candy boxes.
The striations in the plastic top act as tiny prisms, refracting the light thru the plastic sheet at different angles as you shift the way you look at it. the light strikes two different images under the plastic, depending on the angle.
"Chatoyance" is the word, the same effect works on wood with strongly inclined grain, making it appear darker or lighter in color depending on the angle you look at it.
Ray
Ray,
How do they fit two pictures in there? Are they alternating strips?
Janet
Janet,
I presume that is the case, but can't say for sure. I guess that's one thing I didn't tear apart when I was a kid. ;-)
Ray
: )
I'd call Click and Clack. They'll know. They even take marriage counseling questions. Those guys go sooooooo faaaaarrrrr back one of them even worked on the first transistor. (can you imagine ?) He said on the days they got it to conduct before it went pop they would all quit for the day and head for the bar to celebrate.
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