A motion detector device includes a lamp assembly, a junction box assembly with a cylindrically shaped holding arm, a rotation assembly incorporating a sensor seat, a pyro-sensor and circuitry, and a lens assembly. The lens assembly can assume a semi-spherical or cylindrical shape. The lens assembly is integrally formed by a plurality of multifaceted lenses with pre-determined focuses constituting pre-determined focusing views. Each focusing view is defined for a range/distance and angle of detection. The lens assembly can be rotated to select a specific focusing view. The sensor seat is disposed at the focus of the selected focusing view to receive infrared radiation rays. The entire or half or portion of the lens assembly carries lenses making up the pre-determined focusing views.