986 Forum - The Community for Porsche Boxster & Cayman Owners - View Single Post - Porsche Headlight Retrofit [from CAD, prototyping to finish)

Pdwight · 06-29-2014, 09:08 PM

I spent most of my life in the Professional Photo Finishing industry, we had a mirror on our lamp houses called a "Cold Mirror" , it was a piece of glass with a Dichroic coating, it looked slightly silver to the naked eye but was 90% transparent to infrared light, this passed the heat from the 4 500 watt bulbs out of the back of the lamphouse and not into the optics that projected the image onto the photographic paper. Most halogen bulbs that have a built in reflector have this coating, if you look at one with a night vision viewer the silver reflector will appear to be transparent. Im not sure if any of this technology could be used for HID lamp houses....but I was thinking about it while I read your post about the 55W envelopes and ballasts.

06-29-2014, 09:08 PM	#551
Pdwight Registered User Join Date: May 2013 Location: North Alabama Posts: 2,079	Cold Mirror I spent most of my life in the Professional Photo Finishing industry, we had a mirror on our lamp houses called a "Cold Mirror" , it was a piece of glass with a Dichroic coating, it looked slightly silver to the naked eye but was 90% transparent to infrared light, this passed the heat from the 4 500 watt bulbs out of the back of the lamphouse and not into the optics that projected the image onto the photographic paper. Most halogen bulbs that have a built in reflector have this coating, if you look at one with a night vision viewer the silver reflector will appear to be transparent. Im not sure if any of this technology could be used for HID lamp houses....but I was thinking about it while I read your post about the 55W envelopes and ballasts.