Archived posting to the Leica Users Group, 1998/06/07
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]> From: Jeff S > -----Original Message----- > From: Gary Todoroff <datamaster@humboldt1.com> > >The RT300 . . . A special "dichroic" mirror sits at 45 > >degrees to reflect the bulb down that path. My mirror has a mottled > >appearance with a green cast to it, which is probably reducing light output > >and maybe even affecting the color. Does anyone know who carries the mirror > >as a part? Can it be resurfaced? (Leica no longer carries RT300 parts). > > > Very interesting, Gary; I wonder if it's using a "cold mirror" to reduce > damaging heat, rather than a very thick heat absorbing element, as the > American Kodak projectors do. Jeff - To quote form the RT300 Instruction Manual: "Dichroic mirror heat reducing system - to remove heat without color distortion." Directly behind the mirror, a spring-clipped sheet-metal bracket would appear to absorb the IR heat, and a couple of slots nearby are probably part of the fan duct-work for cooling. Besides being fully Kodak Carousel compatible (including their dissolve units), the RT300 dichroic mirror system was reported to submit the slide itself to one of the lowest temperatures of any projector. The mottled, green pattern on my RT300 mirror is a circular shape in the same size as the projector bulb. I'm wondering if anyone else with an RT300 has a similar condition on their mirror. Thanks, Jeff, for the Edmund Scientific lead - I'll check it out. Gary