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Tags optical illusions

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Old 8th March 2019, 09:51 PM   #1
Cheetah
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Visual Illusions

I found this pic I made once playing around with a graphics program.

It appears to have four orange/magenta, two orange/green and two cyan/magenta parts spiraling out from the center.

Spiral Illusion III.jpg


What are some of your favorites?
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Old 8th March 2019, 11:33 PM   #2
SusanB-M1
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There's an art gallery in Buffalo (although it might be Washington, but can't remember as I was there in 1981 ) where as you walk towards a gap and turn left around a wall, you see a picture, which is definitely flat!, become three-dimensional. It is painted in a geometrical fashion so that the effect is a hemisphere. I used to have a link to it but have just tried it and it says 'sorry - we can't find this page' or something. It was absolutely fascinating. You can go up close and see how the painting - about 8ft square - was painted,, but you can't see it as flat. I can still see it in my mind's eye.

Albright-Knox was part of the title I had in link, but I don't know if that means anything now!

ETA I clicked on your link - I can see it approximately, but not the illusion, I'm afraid.

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Old 9th March 2019, 12:25 AM   #3
Cheetah
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Originally Posted by SusanB-M1 View Post
ETA I clicked on your link - I can see it approximately, but not the illusion, I'm afraid.
If you saw "four orange/magenta, two orange/green and two cyan/magenta parts spiraling out from the center" you were fooled.

Anyone want to guess?

The illusion is ...
that the green and cyan appear so different but are actually the same colour.
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Old 9th March 2019, 04:01 AM   #4
macdoc
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I like the motion illusions





http://mesosyn.com/mental8-1.html

and

https://www.today.com/health/best-op...orkout-t100868
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Old 9th March 2019, 11:09 AM   #5
WhatRoughBeast
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My all-time favorite is the higher-level
invisible gorilla illusion.
Of course, it does have the drawback that it only works once.
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Old 9th March 2019, 07:21 PM   #6
Trebuchet
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Originally Posted by WhatRoughBeast View Post
My all-time favorite is the higher-level
invisible gorilla illusion.
Of course, it does have the drawback that it only works once.
But if you change it up, as in the second video, you only see the gorilla and not the other stuff.

That might be the worst gorilla costume in history, by the way.
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Old 10th March 2019, 09:31 AM   #7
Squeegee Beckenheim
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The Amazing Colour-Changing Card Trick:

YouTube Video This video is not hosted by the ISF. The ISF can not be held responsible for the suitability or legality of this material. By clicking the link below you agree to view content from an external website.
I AGREE
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Old 10th March 2019, 10:36 AM   #8
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A variation on the gorilla illusion:
YouTube Video This video is not hosted by the ISF. The ISF can not be held responsible for the suitability or legality of this material. By clicking the link below you agree to view content from an external website.
I AGREE
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Old 12th March 2019, 07:40 PM   #9
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Old 15th March 2019, 11:19 AM   #10
Spektator
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There's an interesting illusion, Adelson's Checker Shadow, that fifteen years or so ago caused quite a tempest in the JREF teapot. Basically, a sketch shows a green cylinder on a white-and-gray checkerboard background; some of the "white" squares are actually gray. It's quite plainly an optical illusion but one member--Interesting Ian, if I recall correctly--insisted that no, the colors WERE different, because he SAW they were different.
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Old 15th March 2019, 05:31 PM   #11
Red Baron Farms
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Originally Posted by Cheetah View Post
If you saw "four orange/magenta, two orange/green and two cyan/magenta parts spiraling out from the center" you were fooled.

Anyone want to guess?

The illusion is ...
that the green and cyan appear so different but are actually the same colour.
No those two are different. There are illusions, but that is real.

It's easy for a skeptic to test this. Zoom in. block all except the green and the cyan where they touch. Same color? Nope.

You have blocked out the illusion part, yet the colors are still different, then that wasn't it.

The illusion is that the color green changes shades slightly to look almost bluegreen
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Old 15th March 2019, 09:18 PM   #12
Cheetah
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Originally Posted by Red Baron Farms View Post
No those two are different. There are illusions, but that is real.

It's easy for a skeptic to test this. Zoom in. block all except the green and the cyan where they touch. Same color? Nope.

You have blocked out the illusion part, yet the colors are still different, then that wasn't it.

The illusion is that the color green changes shades slightly to look almost bluegreen


They really are the same colour.


Spiral Illusion Crp.jpg
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Old 15th March 2019, 11:21 PM   #13
Red Baron Farms
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Originally Posted by Cheetah View Post


They really are the same colour.


Attachment 39759
you mean the blue green is the same as the green?
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Old 16th March 2019, 01:50 AM   #14
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With the colour illusions, you can open them in photoshop and just compare the colour values to check if they are the same.
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Old 16th March 2019, 05:29 AM   #15
p0lka
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this motion one is cool.





This colour one actually demonstrates that the colours are the same, but it's too big for the forum so I have to link to it.

https://i.imgur.com/hxJjUQB.gif

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Old 17th March 2019, 05:34 AM   #16
Cheetah
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Originally Posted by Red Baron Farms View Post
you mean the blue green is the same as the green?

Yes.
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Old 17th March 2019, 02:46 PM   #17
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Originally Posted by p0lka View Post
this motion one is cool.

http://www.internationalskeptics.com...ictureid=12099



This colour one actually demonstrates that the colours are the same, but it's too big for the forum so I have to link to it.

https://i.imgur.com/hxJjUQB.gif

Similar to when I use Netflix and scroll through the titles, the white text seems to follow slightly behind the rest of the box images.
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