There is disclosed a light source module comprising a high intensity discharge light source; optical elements including at least a reflector for redirecting and focusing the light emanating from said light source; and electronic elements for supplying said light source with voltage and current of a predetermined waveform and magnitude. The light source may have optical and/or electric parameters at least partially different from optical and/or electrical standard parameters of a light source of identical type. In order to provide a predetermined illuminating beam pattern compatible with the standard, the optical and/or electronic elements are adjusted to the optical and/or electrical parameters of said light source.