Neat optical illusion

[olderman]

The first two illusions didn't work for me, but the last one definitely did.

 

[dasdoing]

The black hole doesn't work for me

always liked this one

they are all the same size

 

[olderman]

I don't get it. Is it sorcery?

 

[Soniclife]

I don't get it. Is it sorcery?

It's some form of perspective trick, I don't think all the tubes are the same height, look carefully as they are moved. Or it's sorcery.

 

[sergeauckland]

It looks to me like an anamorphic projection, similar to the advertising on football pitches that looks right to the camera, but totally skewed when seen from above.
There was an album cover by Steeleye Span that used the same trick.
Very clever in any event.
S

 

[Killingbeans]

Found an STL and had a look in a slicer. The tubes are identical, but their edge changes hight in a specific wavy pattern.

Definitely going to print one when I have the time to ignore my noisy old Prusa i3 MK2.

 

[Soniclife]

It looks to me like an anamorphic projection, similar to the advertising on football pitches that looks right to the camera, but totally skewed when seen from above

And this very famous example.

 

[JSmith]

JSmith

 

[JSmith]

The black hole doesn't work for me

always liked this one

View attachment 211202

they are all the same size

This is due to the Ponzo Illusion;

... it's a photoshopped image though with the same car repeated 3 times, whereas 3 identical real cars parked that way wouldn't look the same.


JSmith

 

[RayDunzl]

Gets more interesting as he tries to defeat the illusion...

 

[olderman]

Gets more interesting as he tried to defeat the illusion...

Very cool.

 

[holdingpants01]

 

[Axo1989]

I don't get it. Is it sorcery?

The tops of the tubes have a specific height profile, like a wave. Like those 'square' skateboard wheels (from another poster) that do the same trick. Plus diffuse lighting to avoid giveaway shadows in the wrong places.

 

[Axo1989]

Often cited as proof of the perils of listening to audio gear you can see, but really not that in terms of specific mechanism. In the trick video the phonemes are the same of course, but real-life 'ba' and 'fa' are also sonically similar enough to not distinguish reliably (refer to blind testing in the linguistics literature). The video image is presented to trigger categorical perception (storage and retrieval of phoneme categories in long-term memory) to differentiate. As a general example of how visual stimulus can cue perception this is fine, but extrapolating this too comprehensively to material that can also be experienced non-categorically, like music, is tenuous.

 

[JSmith]

The ambiguous cat...

The white circles appear to form a circular shape that rolls around the inside of the circumference of the red circle. But of course, this is an optical illusion so that couldn't actually be the case. The white circles are actually all moving in a straight lines, the timing just happens to create the illusion that they're moving in a circle.

Is it moving?

Which way is the horse turning?

How many horses are there?

The hidden tiger?

Here kitty kitty... (shake your head)

This is real;

'Hovering ship' photographed off Cornish coast by walker

An illusion called "superior mirage" caused the vessel to look like it was hovering above the sea.

www.bbc.com

BBC meteorologist David Braine said the "superior mirage" occurred because of "special atmospheric conditions that bend light".
He said the illusion is common in the Arctic, but can appear "very rarely" in the UK during winter.
Superior mirages occur because of the weather condition known as a temperature inversion, where cold air lies close to the sea with warmer air above it.
Since cold air is denser than warm air, it bends light towards the eyes of someone standing on the ground or on the coast, changing how a distant object appears.
Superior mirages can produce a few different types of images - here a distant ship appears to float high above its actual position, but sometimes an object below the horizon can become visible.

JSmith

 

[Shiva]

This thread led me to a youtube channel called Grand Illusions, which I've often visited over the years. here, something completely different. but still interesting. The Eulers disc.

 

[Killingbeans]

No red pixels in this picture:

 

[Axo1989]

No red pixels in this picture:

View attachment 365751

That appears obvious, do people report seeing red strawberries? I'm guessing some do.

 

[dasdoing]

 

[dasdoing]

That appears obvious, do people report seeing red strawberries? I'm guessing some do.

well, we can see that the colors are off, so our brain can adjust it.

if we correct it a little: