Archived posting to the Leica Users Group, 1996/08/25
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]The information, founded oro unfounded, has been published in most of the popular photography magazines a number of times over the last 3 decades. The reasoning is the same as everyone observes with light bulbs in general. More than 90% of bulb failures occur when you turn on your lights.... the sudden change in temperature and the expansion that results causes the breaks. The fan/bulb/cooling theory works the same way. It has been reported numerous times that a very slow, gradual air cooling is best for projector bulbs and that the more rapid cooling produced by a fan causes the bulbs to fail faster. I have no way of knowing if this is true, but it always seemed logical to me. And, with a careful Lexus/Nexus check, I suppose someone could find a dozen articles about it. I do recall in my 28-year association with National Geographic that the instructions to picture editors were to never leave a slide in the projector gate and to simply turn off the unit and let it cool on its own. Fred Ward Replied: Forwarded 25 Aug 96 15:58