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Re: How does the AstraIIIb split mirror work?
From: Jim Thompson
Date: 2004 Apr 27, 07:06 -0300
From: Jim Thompson
Date: 2004 Apr 27, 07:06 -0300
> -----Original Message----- > From: Trevor J. Kenchington > Are some horizon mirrors given low-reflectivity coatings? I have been wondering in fact whether the clear glass portion of this mirror has a slight increased reflectivity coating of some kind that allows plenty of light to come through the glass from the horizon, but also allows more reflection of the index mirror's image from the clear glass than plain glass alone? This would create the effect that I have been enjoying with this traditional split mirror add-on that I bought from Celestaire a couple of weeks ago: persistence of the index mirror's image over the clear glass portion. I had anticipated that the celestial body would disappear at the center of the FOV. This phenomenon is what started this thread, which has been very educational. Jim.
