I have a Canon 550D with a widefield 10-18mm lens.
I am looking for dew zapper options where I cannot get access to mains or 12v battery power. This is for an overseas trip, so the option must be very light and transportable. (No car batteries) Suggestions?
You can get chemical handwarmer packs, just break the seal and shake it and it will generate heat for a couple of hours. You could strap that to a lense easily. I used them skiing in Canada, and you can usually find them in ski gear stores here.