Homemade sky beamer

I've always been fascinated by Philips's UHP lamps. Those operate under truly mind-boggling conditions and have superlative characteristics. It was my good fortune to have worked on some aspects of the technology at a time when the company pushed the boundaries towards brighter and more powerful sources. Naturally, I got my hands on a few of those lamps (and their electronic ballasts) and I played quite a bit with that technology, resulting in the scene depicted in the photo above, among other things. It is a key characteristic of UHP lamps to have a near point-like source of light of extreme brightness, which enables the projection of a very narrow beam of light when used in conjunction with a parabolic mirror. In the case shown here, the projector is fitted with a small 200 W lamp, which is surprisingly effective in this sky beaming application.