I've finally experienced conditions where I could not use Lymax.
Epic humidity. We set up, clear night and within 15 minutes everything was dripping with dew, the little valley close to us was filled with fog and so was a little depression the other way. Flashlight looked like a light sabre. I cranked heater to the max, it was burning non stop and still the corrector was occasionally suspect when viewing at zenith. My SCT was acclimatised to begin with, but after some time I noticed tube currents (M11 at 100x), so I just did low power nebulae observation and called it quits when I started shivering.
Using Lymax under such conditions would essentially be pumping water into the OTA.
Edited by BGazing, 07 July 2019 - 11:57 AM.