A method for constructing a lamp for radiating a warning signal within a desired polar angular range around a mean polar direction includes the steps of fixing a base body at a mounting location, arranging each of an annular support element having an annular reflector, an inner and an outer annular optical system concentrically around a lamp axis to form an optical arrangement and arranging a plurality of lighting elements on the annular support element in an annular distribution around the lamp axis. The annular reflector, inner annular optical system and outer annular optical system and portions thereof are shaped to reflect and/or direct light radiated by the plurality of lighting elements in such a manner that light emerges from the outer annular optical system in a direction within the desired polar angular range around the mean polar direction.