Optical illusions that flip between concave and convex

[berkeman]

 

[Borek]

That's a classic, same happens with Moon craters that look either convex or concave on photos. And a bit similar to the hollow-face illusion.

 

[256bits]

The bowls were easy.
Finally, it took several seconds to get the top left tray to flip .

 

[davenn]

That's a classic, same happens with Moon craters that look either convex or concave on photos.

Yeah, I have always found that one screwy on the eyes/brain
Also happens on hilly/mountains views, on, say on google earth

 

[Keith_McClary]

http://illusionoftheyear.com/cat/top-10-finalists/2021/
If you hover over the "Illusions" tab, it goes back to 2005.

 

[bland]

I saw a tiny fuzzy version of this and I liked it so much I redrew it in vector and added some randomness, it's very simple but mesmerising. I tried it in different colours but monotone looks best, being vector it can be printed at any size. Enjoy.

 

[DaveE]

Sorry in advance for making y'all waste so much time on this web site. Lots of optical illusions here:
http://www.ritsumei.ac.jp/~akitaoka/index-e.html

 

[bland]

Another one redrawn, not vector. Simple is always best.