Foggy Lens
 

After my booboo with the fogged lens, I'm wondering for next time, what works at keeping the lens fog free? I read a few suggestions on keeping the lens warm before exiting the building but is there a better answer?

The thing you have to remember is to avoid rapid temperature transitions. Keeping the lens in a camera bag or similar, and keeping the bag lid closed for half an hour or more whilst the temperature between the air inside the bag stabilises with the temperature of the air outside the bag is a sensible precaution.

We're dealing with some pretty basic laws of physics here so I'd be very interested if anyone has found a way to beat them.

Middle of last December I went into Stratford Butterfly House with the Panasonic and Raynox. The Raynox and UV filter on the pana fogged up as soon as I went in. Cold and dry outside, hot and humid inside. I gave the Raynox and the filter a quick wipe. Breathed on them and wiped them again.

This was taken 5 minutes later.