Question: Have Your Lenses Ever Developed Less Accurate Focus in Severely Cold Temperatures?

I’m going to do something on the blog today that I’ve never done before, and that’s ask a question to the ENTIRE INTERNET! Well, ok, that’s a slight exaggeration, but this can’t hurt to try. I’m doubtful that I’ll find the answer immediately from regular readers, but by putting this question out there publicly, I hope that perhaps one day someone else might be searching Google for the same information, and then stumble upon this post. Many of you know that I shoot with the wonderful Canon 400mm f/4 DO IS II  super telephoto lens. This lens is sharp as