Well, you are supposed to pick out 2 points on the image and then look through the image . When I did that a huge guppy pounced at me and then disappeared. Working around one point I think I saw a coiled snake but not it's head! regards
I note that the order of blue vs green is reversed on each adjacent circle, which seems to be why it looks like half are turning one way, and half the other. I wonder, if all the circles has the blue-green going the same way, would it look like everything is turning the same way? Or would the illusion go away because the constrase in patters is what sets it off? [Paul S]: Look at it at an angle and the illusion stops. Not for me, though it might be reduced a bit in effect. Curious. Closing one eye has no effect on the motion part of it. Dunno if HST is pulling our legs about an embedded steroscopic image; I never can see those things anyway. But the illusion of motion is there, and has nothing to do with stereo vision, IMO. [ October 07, 2003: Message edited by: Jim Yingst ]
Originally posted by Jim Yingst: I note that the order of blue vs green is reversed on each adjacent circle, which seems to be why it looks like half are turning one way, and half the other. I wonder, if all the circles has the blue-green going the same way, would it look like everything is turning the same way?
I printed it in black and white and the effect was still there.
Right, as Elaine said - but when you do that, do blue & green translate to two different shades of gray, or do they look the same? If they're so close in tone that you can't tell the difference, I doubt you'll see much motion. But maybe I'm wrong. Someone with Photoshop or something similar might try making a version of this in which all the circles are copies of the same pattern, rather than half going one way and half the other. I've got very, very primitive image editing capabilities at the moment...
My theory is as follows: Peripheral vision is distorted. When you move your eyes the amount of distortion changes creating movement illusion. It is like looking through imperfect window glass. If you move your head, the outside world appears to change shape. This implies the following: 1)The point you focus at never moves. 2)If you look from a distance there is no movement, because entire picture is in focus, outside peripheral vision 3)Movement stops even in your peripheral vision if your eyes don�t move. This is because distortion at point X is constant. 4)The more your eyes shake and wonder around, the more movement you see. This is because distortion at point X changes, as its image enters the eye at different angles. Colors only help see the movement. The movement still exist even if you look at white screen, you just don�t notice it.
Joined: Mar 25, 2001
JY: Dunno if HST is pulling our legs about an embedded steroscopic image; I never can see those things anyway. As far as I can tell, yes, HS is pulling our leg. When I look at it, um, stereoscopically, no hidden 3-d image emerges. The motion illusion goes away and the circular patterns deepen into wells with the the four complete circles (six, under "normal" viewing) seeming deeper than the partial circles. The key to stereograms is that there are slight discrepancies in the repeated pattern. This one seems entirely regular to me. [ October 07, 2003: Message edited by: Michael Matola ]
Joined: May 15, 2002
JY: But the illusion of motion is there, and has nothing to do with stereo vision, IMO. The image has been named Notmoving.Gif. See here for the image in isolation web page
I think you are supposed to see something and no, I wasn't kidding. Though I can't see a guppy, today. I can see an owl. The snake tongues sticking out from under the pile of coils may have added to the illusion for me. regards [ October 07, 2003: Message edited by: HS Thomas ]
Here's another neat illusion that abuses retinal processing of colors. If you stare at the black cross in the center, the magenta spots will disappear and be replaced by a single light green spot that is moving around the center.