The topic of the visual illusion Dr. Hoi discussed a lot about this with us in the presentation which reminded me of an image I saw on the internet. It is called “Checker shadow illusion” published by Edward H. Adelson. It is an image of a green cylinder placed on a checkerboard. The image is marked with a white and black square chessboard with A and B. The grids marked A seem to be darker than the grids marked B, but they are actually the same gray scale. Basically, Adelson explains that the human visual system makes judgments about the colors of objects seen in the real world. In this case, to determine the color of the chessboard under the shadow, the actual light received by the eyes is not enough. The human visual system uses several techniques to compensate to determine the gray color of the surface.

 

More information about this optical illusion: https://en.wikipedia.org/wiki/Checker_shadow_illusion

 

I personally love gray tone colors and I am recently doing some paintings with gray tone colors. Therefore, I decided to paint the checkerboard image on the watercolor paper using the methods I usually do on my paintings, which are to simply observe, and paint. To explore the colors and to see the picture would still be content with the illusion if I do it manually. It finally comes up that the illusion is not as obvious as the original image, but I can still see different gray scales even if I use the same gray.