If you cover the penumbra with a black marker, the perception of the border _____.
A) remains constant
B) changes from an illumination edge to a reflectance edge
C) changes from a reflectance edge to an illumination edge
D) can be predicted from the ratio principle

Question

Quizplus · Accepted Answer

The penumbra is the area of transition between two regions with different levels of illumination or reflectance. By covering it with a black marker, the reflectance of this region increases, which changes the perception of the border from an illumination edge (brighter region transitioning to a darker region) to a reflectance edge (region of higher reflectance transitioning to a region of lower reflectance).

If You Cover the Penumbra with a Black Marker, the Perception