A light detector which includes a housing having front and rear walls, a light receiving section disposed on the front wall, and displays disposed on the front and rear walls for showing the location of received light relative on the light receiving section. Also disclosed is a laser level including a motor, a shaft driven by the motor, a housing fixedly disposed on the shaft, the housing having a bore therein, a barrel, and a screw disposed on the housing and contracting the barrel for adjusting the pivotal position of the barrel.