I have found that my Nanuk hard case is good at preventing condensation when I go in and out of various environments. The trick is to let things come up to temperature slowly. I have had the Hassy in the cold a number of times and no problems so far. Enjoy Japan, one of my favourite urban places to travel, if you visit a Yodobashi camera store, maybe they will have a bunch of Hasselblad lenses to try out. I never left Japan without acquiring some new camera gear....