This past weekend I was trying get some photos on a small mountain, but the weather was rainy and I was basically in the clouds about half way up. (They were very low.) This produced some really cool lighting, but I got very few usable shots because the lens kept fogging over. I tried leaving it exposed to the air, and keeping it closed in the bag till I was ready, but no matter what it would fog over in seconds. Any suggestions to help shoot in fog or clouds at altitude? Thanks!
It sounds as though you were actually in the clouds and the moisture collected on your lens. Did it also collect on other stuff, like your clothes, or whatever? If it did, then you had no choice but to carefully wipe off the lens and shoot before it fogged up again. This situation is, in my opinion, a case where it would've been handy to have a UV filter (or a plain glass filter) attached to your lens because the moisture would've collected on the filter and, if during the process of wiping off the moisture, you inadvertently caused a scratch, it would've been on the relatively inexpensive filter and not the front lens element.