Up here in Darwin , especially when the dry season is comming to and end ,, late september that is a real problem , dew , but its the other way around , eg taking the scope from a cooler 24 degrees air cond house to the 32 degrees and 95% humidity out side , we get dew build up .
, its a pain .
Thats when a hair drier comes in handy .
But for storage I use those miosture absorbing pads from Bunnings , $15 for a pack and leave the scope opened lying horizintal over night inside with the air con and fans on after use , and place 1 pad in the eyepiece end and 1 in the dew shield till next time ,
. its a pain in the XXXX but you gotta do it up here , or any where its really humid .
The Mould builds up so fast here it's amazing .
Every so often I place the pads in the oven for 20 miniutes at about 80 degrees to dry them out , this works for 1/2 a dozen times until they dont work any more .
Brian.