Telegraph, 28 October 2016
Glossy legs or painted legs, an optical illusion
This week, a new ‘optical illusion’ picture has hit the internet in a big way. Do you see glossy legs or legs with white paint on them? Daniel Hardiman-MCartney, Clinical Adviser at the College explained why you might see what you see in the Telegraph. He also explains in full here:
“The explanation for this is similar to that of the black and blue dress; ambiguity. For the dress, it was about ambiguity in the colour constancy, this time it’s about surface ambiguity. Metallic, wet or shiny surfaces reflect light in a unique way and our visual perceptual system has to spot clues in the reflected light in order to differentiate between shiny and matt, despite perhaps being the same apparent colour. Vision scientists think that one of the important clues the brain uses to tell if a surface is wet or metallic is the skew of the spectral luminance; how much light is being reflected and where it is reflected from.”
Are the legs glossy and wet, or are they painted with white paint?
For those who initially see the image as a pair of shiny wet legs:
We use past experiences and our knowledge of objects to prejudice our interpretation of what we see, legs are more commonly wet and shiny, much less commonly covered in white paint. In this case it may be the first time you have seen a pair of legs with white paint on them. The lack of focus on the skin, making the skin look like plastic and tight crop adds to the ambiguity. What room is the photo taken in?
For those who initially see the image as a pair of matt painted legs:
There are markers and paints in the right of the image. The legs are matt without a diffuse specular reflection like you would expect if they were wet, so the white strip is not a highly skewed reflection of light, it is white paint, as the person who took the photo has confirmed. Now try covering the pens and imaging the photograph is taken in a bathroom, do the legs now look wet?
It always comes back to that dress!
One interesting theory that came up with the dress was that whether you were an night owl or morning person influenced how you initially perceived the image, night owls opting for white and gold in the first instance as more of their day is spend in rich yellow sunlight. With this picture, how you perceive the image may influence where you believe the location of where the photo was taken. Those who assume the legs are wet initially may believe the image is taken in a bathroom, whereas those who are aware that the legs are painted and can see pens in the right of the photo may assume the location is more likely a study. These context clues contribute to how the visual system will decide to decode and perceive the image.