PRG Foton High-CRI LED: Can a Great Photo Light Show Us a Headlamp Spectrum Fix?

Daniel Stern, DVN Global Editor
Much has been written about the kind of light that comes from LED headlamps: They look nifty; they have a high colour temperature, they give off a blue-white light, they appear brighter than halogens for any given intensity, and (lest we forget!) that long-serving, oft-recycled marketing slogan, they’re “closer to natural daylight”. Fact is, though, artificial light produced by a non-blackbody source—that is, by something other than a glowing filament—usually isn’t much like natural daylight at all. And it looks as though the light we’ve been making so far with LED headlamps may not be the best kind for headlamps. Automotive Lighting’s Dr. M. Hamm presented at ISAL this past September a paper raising unsettling new questions about LED headlamps as they’ve been made so far: “…LED threshold detection appears to be significantly weaker than halogen. The reasons are unknown, a first explanation could be the differing spectral power distribution leading to different visual acuity and thus increased thresholds.” Dr. Hamm takes care to be clear that this preliminary finding requires more investigation before it can be considered a fact with an established causal chain, and indubitably he and his estimable colleagues will carry on with the kinds of research needed to scrutinise the matter thoroughly.