Mobile screen brightness easily auto-adjusts in a variety of conditions so that it remains easily visible. However, if the screen faces the sun, the objects on the screen become difficult to discern with the human eye.
What could be the reason that best explains this phenomenon?
A light ray that bounces off a surface with high
specular reflection bounces back following the law that the angle of incidence equals the angle of reflection as divided by the normal to the surface.
A mirror has high specular reflectance.
In contrast, a rough piece of wood, for example, has high diffuse reflectance, where the reflected rays will return outward in every direction. A glossy piece of glass can have both types of reflectance, and can act in part like a mirror. So, when a display screen with a glass cover faces the sun, much more light can come right back at you, thus lowering the contrast of the illuminated pixels.
Edited on July 8, 2020, 2:54 am
specular reflection of high gloss screen cover
