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Old 06-16-2012, 08:23 PM
 
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thecoalman, those don't spin....
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Old 06-16-2012, 09:15 PM
 
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What does it mean when they don't spin?

I made FF (13.0.1) full screen and then the image, nada, nothing changed....
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Old 06-16-2012, 11:03 PM
 
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Quote:
Originally Posted by 11thHour View Post
I'm fairly certain the eye has a biological 'frame rate.' IE, our eyes (brains more accurately) still 'see' an image for a certain fraction of a second after actually seeing it. Maybe an eye doc can chime. To answer your other question, I too have seen a car drive by while I was on a sidewalk that appeared to have wheels spinning backwards. Actually I've seen this a ton of times, it's normal. No, they were not the ghetto spinner wheels.
I think I've noticed, when turning on an electric fan, as the blade accelerates, there is a subtle shift from a perception from backwards to forwards, before the spin rate is so high that it just a blur. But I'm going from memory, and I don't have such a fan to test it.
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Old 06-17-2012, 12:54 AM
 
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Quote:
Originally Posted by Tek_Freek View Post
thecoalman, those don't spin....
Well they shouldn't "spin" but there should be a really weird type of movement going on, almost like it's alive. Think along the lines of a pile of worms.
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Old 06-17-2012, 01:05 AM
 
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Quote:
Originally Posted by plwhit View Post
What does it mean when they don't spin?

I made FF (13.0.1) full screen and then the image, nada, nothing changed....
Good question, I don't remember anyone ever saying they don't see it move. If recall correctly the effect is caused by your eye trying to focus in and out. This is old trick, perhaps the lack of movement might be explained by newer monitor/display capabilities. I'm using newer flatscreen and it still works for me so that is just a guess.

Instead of looking at one part of the image try panning from one side to the other.
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Old 06-17-2012, 09:21 AM
 
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Tek, perhaps the people who see wheels going backwards in real life are the same ones that see images of Jesus in burned toast?

I don't think the sodium vapor lamps do it, but I wonder if some of the mercury lamps might give light that has a strong 60 Hertz component that could work as a strobe.
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Old 06-17-2012, 11:03 AM
 
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Quote:
Originally Posted by thecoalman View Post
Well they shouldn't "spin" but there should be a really weird type of movement going on, almost like it's alive. Think along the lines of a pile of worms.
I tried again and it moved some.
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Old 06-17-2012, 04:38 PM
 
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Quote:
Originally Posted by kazyn View Post
It's much easier to see on video because of frame rate syncing up with the RPM of the wheel:


Spinning Wheel - YouTube

It's just how your eyes interpret the incredibly rapidly changing light patterns. Sometimes at the right "frequencies" it will look like they are going backwards. It's a basic strobe effect.
Just fyi my post had nothing to do with watching a wheel on video. I said it's just easier to see the effect, which is why I posted it. The rest of the text explains what you see in person, like you asked about.
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Old 06-17-2012, 04:50 PM
 
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Quote:
Originally Posted by Tek_Freek View Post
I tried again and it moved some.
ROFL....


Seinfeld: It Moved - YouTube
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