gkuep1945 Loc: Dowling Park, Florida

I wanted to try to narrow down whether the problem was mine or the equipment before bothering Canon. UHH people are a wealth of information that I wanted to explorer first.

So far I believe the problem was changing lenses before the equipment fully adjusted to the outside temp. Here in Florida, I have been used to just swap and go. I hadn't considered the low temp and high humidity from recent rain. I should do better next time.

Thanks everyone for helping me figure this out! I appreciate the help!

amfoto1 Loc: San Jose, Calif. USA

Very odd.

I've been using Canon cameras... film and digital... for over 15 years and in all sorts of climates.

I have occasionally had battery issues at very low temps (much colder than 40F). But when that happens the entire camera shuts down, not just the AF. And swapping out to a spare battery that I've kept warm in an inside pocket always immediately revives the camera to full functionality. Once it warms back up, the cold battery that failed also is usable again. That's happened to me with brands other than Canon, too.

mwsilvers Loc: Central New Jersey

I understand, but its still extremely odd that three Canon cameras should all have the identical problem at more or less the same time. Its interesting that all three were using 3rd party lenses at the time, but that should not have been an issue. I use Sigma as well as Canon lenses in cold weather.