Aside from the humidity concerns, we have anecdotal evidence that the ceramic based lamp may be acoustically quieter--see this post in reference to lamp sing.n the early 90’s the HPL lamp was developed in close cooperation of ETC™ and USHIO. A decade later
the ceramic base was the response for applications in humid surrounding where arcing between the
socket and the metal base occurred. As some of our customers prefer the traditional design, we now
re-launch the Metal base type next to our Ceramic base type.
Both types are identical in life-time and optical performances. Certainly they both feature USHIO’s ultra
compact filament design giving maximum intensity with an even circular light distribution ...