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 pivotally connected to the housing, a laser diode module disposed within the barrel, and a screw disposed on the housing and contacting the barrel for adjusting the pivotal position of the barrel.