Original Message: ----------------- >It seems that if there's any significant pupil restriction, then the brightness is set way-way too high=2E I agree=2E I often temporarily turn my Telrad brightness up to 11 just to= find the rings, and then quickly turn it back down such that it is only slightly brighter than the dark gray of the night sky=2E It shouldn't hav= e any effect on dark adaptation=2E As Paul and others mention, though, ther= e is some light loss through the cheap glass surfaces=2E >Anyway, my conclusion, assuming I'm no weirder than anybody else, is that the idea that exposure of one eye to bright light leaves the other other eye unaffected (at least as regards pupil size) is incorrect=2E One more visual astronomy myth that should be avoided! Maybe it does not leave the one eye unaffected, but it is certainly much less affected=2E Everybody who has viewed the moon unfiltered through a telescope has had that "blind in one eye" sensation=2E Tom (only slightly weirder than Brian) -------------------------------------------------------------------- mail2web - Check your email from the web at http://link=2Email2web=2Ecom/mail2web -- See message header for info on list archives or unsubscribing, and please send personal replies to the author, not the list.