polytropos' photos with the keyword: diagonals

Macro Mondays – Mo. 04.05.2020: Diagonale Linien Do you can see the optical illusion? In the main picture it looks as the tiles are swales (concave). In the thumbnail (PiP 1) which is the same picture, you can see that is not! The tiles are elevated (convex), as it should be. It's the same effect as ► HERE (in PiP 4). This effect is called ► The Hollow-Face Illusion. Why this effect appears here (at same picture with different size) I can not answer. :-) ► PiP 1: thumbnail 100x100 of the main pic. ► PiP 2: version 240x240 of the main pic. ► PiP 3: version 500x500 of the main pic. ► PiP 4: the tiles.