Smart Zoom, Innovative introduction of the SLR camera's focus screen technology. Fresnel lens is used to change the Angle of the beam by adjusting the distance between the lens and the light-emitting point. Structural engineers cleverly achieve precise focus adjustment control in small space of the lighting, so that the fixture can accurate transform beam angle to 17°,25°,36 °in any time , without having to change the lighting, it can easily create different lighting effects.