Cheapo Retroreflector aka true environmental light sensor
A retroreflector is basically a mirror that reflects light back directly to its source no matter the orientation. It basically can take a light source of any angle and reflect it back at the source. This "retroreflector" Takes incoming light from the outside and bounces it around in the half sphere, until it hits the CdS cell. This means that even with minimal light (not completely dark) the sensor still recieves more light than if you were to use the raw sensor. More later.