I have never done the freezer test, being I live in an area where below freezing while hunting is the norm never saw the need to I guess. In any regard I have yet to find an optic that was subjected to cold air for a period to bring the ambient lens surface temp down significantlynot fogon the externallens surfaceto some degree when palced inwarmer air. Leupolds, Elites, Zeiss, etc are included...some worse then others.Such an event doesn't bother me as it has never been an issue in regards to hunting.

Skeeter,I think I'm getting a better picture of the nitrogen purging it is good going from warm to cold,not cold to warm I never knew it made a difference till I asked.but I am relieved to know the difference thanks.........Ted