The invention relates to the technical field of lamps, in particular to a light sensor, a lamp and a using method. A light sensor includes: a condenser lens; a light sensor; the shell is provided with a containing space, a through hole is formed in the shell, the
condensing lens and the light sensor are fixedly arranged in the containing space of the shell, part of the
condensing lens is arranged in the through hole, the
condensing lens and the light sensor are correspondingly arranged, the condensing lens is used for collecting light outside the shell, and the light sensor is used for sensing the light outside the shell. And the light sensor is used for sensing the change of the light rays collected by the condensing lens. The invention provides a light sensor, a lamp and a use method, and aims to solve the problems that a lighting element and a sensing element are fixed through two parts in the
design process of an existing sensor, and in later
assembly and use, due to the fact that the lighting element and the sensing element have installation errors, positioning of the lighting element and the sensing element is not accurate, and the cost is low. The use effect of the sensor is affected, and the experience is poor.