Illusion of lightness

"The morning sunlight"

It appears as if intense morning sunlight were projected.

Copyright Akiyoshi.Kitaoka 2005 (April 5)


Illusory white spots scintillate in the crosses of gratings (= the scintillating grid illusion or the Hering (Hermann) grid illusion). In addition, illusory blur appears in the oblique direction when observers approach or move away from the image fixating at the center.

Copyright A.Kitaoka 2004 (June 16)

*Goban means a board where go (a kind of game like chess) is played.

"A scintillating LSI"

Illusory black spots scintillate in white squares.

Copyright A.Kitaoka 2004 (May 12)


"Fountain" appears at each cross.

Copyright A.Kitaoka 2003

"Soundproofing walls of highways"

The gray flanked by walls appears to be different in lightness from the gray in the surround, though they are actually identical.

Copyright A.Kitaoka 2003

"More white"

The white in diamonds appears to be more white than the white in the surround.

Copyright A.Kitaoka 2003

cf the Logvinenko illusion

Thanks to Bruno


*kind of Japanese monters

Circles appear to be dark-gray or light-gray, though they are of the same luminance (the snake illusion). Moreover, the circles appear to change in size, though they are identical.

Copyright A.Kitaoka 2003

"Shooting stars"

Illusory white lines that run from upper-right to lower-left, are seen. This is a kind of the pincushion grid illusion. In addition, gray gratings sometimes appear to move.

Copyright A.Kitaoka 2003


Illusory black dots appear to sparkle. See the scintillation grid illusion*.

Copyright A.Kitaoka 2003

*For the scintillation grid illusion, see:

Schrauf, M., Lingelbach, B., Lingelbach, E., Wist, E.R. (1995) The Hermann grid and the scintillation effect. Perception, 24, suppl. 88-89
--- Actually the third author Elke Lingelbach discovered the effect.
Schrauf, M., Lingelbach, B., Wist, E.R. (1997) The scintillating grid illusion. Vision Research, 37, 1033-1038.
Institut fur Augenoptik Aalen --- Click "Taushungen" (illusions).

"A gray grating"

The low-contrast, gray grating appears to move horizontally. Actually, the gray between black diamonds and the gray between white diamonds give the same level of lightness. See the argyle illusion.*

Copyright A.Kitaoka 2002

*Perceptual Organization and the Judgment of Brightness
  Adelson, E. H., Science, 262:2042-2044 (1993).


Half annuli appear to show two different levels of lightness but they are actually identical. The essential illusion of this work was presented by Professor Adelson.

Copyright A.Kitaoka 2002

see Professor Adelson's modulation of the Koffka ring

"Eggs of a frog"

The same gray of circles appears to show two levels of lightness. Anomalous motion illusion also appears.

Copyright A.Kitaoka 2002

see Professor Adelson's snake illusion

"Disappearing circles"

White circles disappear with the Hermann-grid illusion.

Copyright A.Kitaoka 1999