A headlamp includes a tubular housing; an electrical conductor entering the housing and connected to an electrical network; an LED assembly with a ceramic substrate and an LED having a light-emitting front surface; an iris assembly with a toroidal housing, an iris diaphragm and an actuator for adjusting the width of the aperture. A prime lens placed in front of the iris diaphragm and having an annular light block provided proximate a rear surface of the prime lens; and an optical assembly with at least a light focusing lens placed in front of the iris assembly.